Research Paper |
Corresponding author: Ben J. Strohbach ( strohbachben@gmail.com ) Academic editor: Jürgen Dengler
© 2023 Ben J. Strohbach, Marianne M. Strohbach.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Strohbach BJ, Strohbach MM (2023) A first syntaxonomic description of the vegetation of the Karstveld in Namibia. Vegetation Classification and Survey 4: 1241-284. https://doi.org/10.3897/VCS.99045
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Aims: The Karstveld in Namibia has been recognized as an area of high plant diversity. However, this area is also recognised as a hotspot of various forms of degradation including bush encroachment. Minimal baseline data on the composition and diversity of vegetation in this area is available, therefore this paper is a first attempt to rectify this data deficiency. Study area: The Karstveld in Namibia is formed around the Otavi Mountain Range in northern Central Namibia, consisting of strongly karstified carbonate bedrock, rising up to 2000 m a.s.l. The Karstveld includes the Ovambo Basin plains with shallow calcrete soils north of the range, up to the Omuramba Ovambo. Because of orographic effects, the area receives some of the highest rainfall in Namibia, with up to 600 mm per year. Methods: A set of 889 relevés with 868 species was selected from the GVID ID AF-NA-001 database. A partial data set, using trees, shrubs, dwarf shrubs and grasses only, was used for the classification with modified TWINSPAN. The initial result yielded four main groups, according to which the data was split and further classified. Several vegetation types observed during field surveys were not reflected in the classification results; these were refined using Cocktail with known characteristic species. Results: The four main units represented wetlands and grasslands with six associations, a Thornbush savanna – Karstveld transition zone with four associations, Kalahari vegetation with four associations and the Karstveld proper with eight associations. The latter are grouped together as the Terminalietea prunioides, with two orders and three alliances recognised under them. We describe 16 associations according to the ICPN. Conclusions: Although the associations presented in this paper are clearly defined, there exists a high degree of diversity within these. The Karstveld is also extraordinary species rich within the context of the arid to semi-arid Namibian environment.
Taxonomic reference:
Abbreviations: ga = annual grass; gp = perennial grass; GPS = Global Positioning System, referring to a hand-held ground receiver; hl = herb layer, containing all hemicryptophytes, therophytes and geophytes, but excluding grasses (Poaceae); ICPN = International Code of Phytosociological Nomenclature (
Braun-Blanquet, Karst vegetation, Karstveld, modified TWINSPAN, Namibia, Otavi Mountains, syntaxonomy, Terminalietea prunioides, vegetation classification
Although much is known about the flora of Namibia, the assemblage of species in relation to their habitat in specific areas (i.e. “vegetation”) is often less well known and understood (
Within the southern African region, mixed attempts have been undertaken to describe vegetation. In east Africa, potential vegetation maps have been published for several countries, at varying levels of detail (
In Namibia, a similar approach to vegetation descriptions has been followed. Early attempts to collect baseline information on natural resources for land use and conservation planning purposes were confined to conservation areas, in particular the Etosha National Park, the Waterberg Plateau Park and the Namib-Naukluft National Park (
The Karstveld sensu
The Karstveld sensu
The Otavi Mountain Range forms the northern platform of the Damara Orogenic Belt. A succession of clastic and carbonate sedimentation resulted in four main strata (
(a) Topographical map of the study area; (b) simplified geological map of the study area. On these two maps two transects are indicated by red lines. These are presented in Figure
The carbonate rocks of the Otavi Mountains are strongly karstified, forming steep and rough mountain slopes (
To the south the Otavi Mountain Range transitions into the northern zone of the Damara Orogen (
To the east, north and west the Otavi Mountain Range tapers out into the plains of the Ovambo Basin, forming part of the greater Kalahari Basin (
The climate of the study area is a typical summer-rainfall, hot, semi-arid steppe (Bsh) following the classification of
Average temperatures can raise to between 34° and 36°C during the hottest months, whilst the average coldest temperatures are between 4° and 8°C during winter. Frost can occur; up to 5 days of frost per year are expected (
Climate diagram for Tsumeb in the central Karstveld. The diagram follows the scheme of
A data set of 889 relevés with 868 vascular plant species was selected from the phytosociological database of Namibia (GVID ID AF-NA-001) (
All vegetation data were collected according to the standards of the Vegetation Survey of Namibia, i.e. as regular relevés compiled on a 20 m × 50 m plot (1000 m2) plot, whilst plot layout was restricted to a specific habitat (
For the initial relevés done in 1991/92 (data subset North-Kal), no GPS was available, and the position was determined using 1:50 000 topographic map series of Namibia. Later plot positions could be determined by GPS, initially using the old Schwarzeck reference standard (
Overview of data used for this study. All data form part of GVID ID AF-NA-001 (
Relevés | Dataset Name | Number | Year | Season quality | Surveyor | Area of interest | Reference (if any) |
---|---|---|---|---|---|---|---|
1301 - 1307 | DMP | 7 of 422 | 2004 | dry | Marianne Strohbach | South-east of Grootfontein adjacent to Omurambo Omatako | Strohbach ( |
2259 - 2318 | BS-GFT_1999 | 60 | 1999 | wet | B. Strohbach | Eastern Karstveld | |
2772 - 2796 | BS_GFT_2003 | 25 | 2003 | normal | B. Strohbach | Karstveld-Kalahari transition near Maroelaboom | |
3183 – 3546 (intermittent) | MS_BIOTA | 137 of 558 | 2001-2002 | normal | Marianne Strohbach | Southern edge of Karstveld, transitioning into Thornbush savanna |
|
3813 – 4066 (intermittent) | North-Kal | 131 of 344 | 1991-1992 | normal very dry | B. Strohbach | Eastern Karstveld including Omuramba Ovambo and transition to Kalahari | |
4259 - 4350 | Uitkomst_9597 | 92 | 1995 & 1997 | very dry dry | B. Strohbach | John Pandeni Research Station near Grootfontein | |
7683 - 7829 | BS_GFT_2007 | 147 | 2007 | normal | B. Strohbach | North-east and south of Grootfontein | |
7830 - 7869 | BS_Sargberg_2008 | 40 | 2008 | normal | B. Strohbach | Farm Sargberg near Otavi | Strohbach ( |
7902 - 8151 | BS_Oshikoto_2008 | 250 | 2008 | normal | B. Strohbach | Central and western Karstveld up to Etosha border |
The combined data was imported into Juice (
A partial data set comprising trees, shrubs, dwarf shrubs and grasses only, was prepared from the original complete relevés. This resulted in a matrix with 306 species only. This data set reduction was done to avoid confusions with incorrect field identifications over various seasons, composition differences due to seasonal variations and general ‘observer bias’ of especially the ephemeral (herbaceous) component of the vegetation. This reduced data set was used for the classification procedure.
An initial classification was done using modified TWINSPAN (
The classification of the clusters using partial data was transferred to the full data set. During analysis of the resulting clusters some subdivisions were found to be not ecologically interpretable; thus such branches were merged for an ecological interpretable result. Also, some of the grasslands were found to be classified with the Thornbush savanna. Likewise, a wetland type was classified within the true Karstveld types. These groups were manually moved to Cluster 1 (Wetlands and Grasslands) for easier interpretation. It was also realised that some vegetation types observed during field surveys were not represented in the classification results. To rectify this, a refinement of the classification results was done using Cocktail procedures (
Once an ecologically interpretable result was achieved, phytosociological tables were compiled and the synopsis for various associations extracted. Diagnostic species were determined and sorted using the phi coefficient of association (
The resulting terminal units were formally described as associations according to the International Code of Phytosociological Nomenclature (ICPN;
The average cumulative cover values of the trees, shrubs, dwarf shrubs, perennial grasses, annual grasses and forbs was calculated based on the available growth form data. Structural descriptions follow
As bush encroachment is a topic in the current study area, Simpson’s Dominance Index and Smith-Wilson’s Index (Evar) (
From the original data set, a subset consisting of relevés of the Thornbush – Karst transition, Kalahari and Karstveld (clusters 3, 4 and 5) was compiled for importing into PC-Ord 7.02 (
This data set was used to calculate an NMS ordination (
The classification results are depicted in Figure
Within the grasslands associated with the Thornbush – Karstveld transition, two distinct associations were observed during field work, recognisable by different species composition and different habitats These however were not separated by the modified TWINSPAN classification. For this, Cocktail (
Also in the Thornbush – Karstveld transition, thickets with Olea europea subsp. africana were found in the plains and footslopes of the Otavi mountains. These differed from the thornbush shrublands (association 3.1.1.3) further south through a far denser and higher structure and containing several distinct species not found elsewhere. Although these were not separated using modified TWINSPAN, these were recognised as an association based on their composition and physiognomy. To separate this association from the remainder of the thornbush shrublands, Cocktail was employed, searching for relevés containing Olea europea subsp. africana, Enneapogon desvauxii, Elaeodendron transvaalensis, Fingerhuthia africana, Euclea undulata, Vachellia karroo and Croton gratissimus. All selected relevés come from the clusters 3.1.1.3.1 and 3.1.1.3.2 and were grouped as 3.1.1.4.
An abbreviated synoptic table, containing only diagnostic and/or constant species, is provided with each major grouping (Tables
The ephemeral wetlands are characterized by the presence of Lagarosiphon muscoides, Nymphoides indica subsp. occidentalis, Eragrostis rotifer, Panicum gilvum, Nymphaea nouchali var. caerulea, Marsilea nubica and Echinochloa species. The vegetation is dominated by the plant families Poaceae (9 species), Cyperaceae (6 species) and Asteraceae (4 species). Within central and northern Namibia, a number of these ephemeral wetlands, locally referred to as vleys, are known (
Abbreviated synoptic table for the wetlands and grasslands, showing all species occurring in more than 10% of relevés of these groups, with fidelity (phi coefficient x 100) and frequency of occurrence (%).
Higher grouping | 1.1 Wetlands | 2.1 Grasslands | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
2.1.1 Ishana grasslands | 2.1.2 Mesic grasslands | |||||||||||
Association | 1.1.1.1 | 1.1.1.2 | 2.1.1.1 | 2.1.1.2 | 2.1.2.1 | 2.1.2.2 | ||||||
No of relevés | 4 | 3 | 3 | 11 | 10 | 6 | ||||||
Species | phi | % | phi | % | phi | % | phi | % | phi | % | phi | % |
Nymphoides indica subsp. occidentalis | 100 | 100 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Eragrostis rotifer | 86 | 100 | --- | 0 | --- | 0 | --- | 18 | --- | 10 | --- | 0 |
Echinochloa pyramidalis | 67 | 50 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Cyperus compressus | 67 | 50 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Nymphaea nouchali var. caerulea | 67 | 50 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Lapeirousia avasmontana | --- | 0 | 79 | 67 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Marsilea nubica | --- | 0 | 79 | 67 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Panicum gilvum | --- | 0 | 79 | 67 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Combretum imberbe | --- | 50 | 64 | 100 | --- | 0 | --- | 0 | --- | 30 | --- | 17 |
Sporobolus spicatus | --- | 0 | --- | 0 | 100 | 100 | --- | 0 | --- | 0 | --- | 0 |
Leptochloa fusca | --- | 25 | --- | 0 | 87 | 100 | --- | 0 | --- | 0 | --- | 0 |
Odyssea paucinervis | --- | 0 | --- | 0 | 86 | 100 | --- | 27 | --- | 0 | --- | 0 |
Sporobolus acinifolius | --- | 0 | --- | 0 | 83 | 100 | --- | 36 | --- | 0 | --- | 0 |
Chloris virgata | --- | 0 | --- | 0 | --- | 0 | 89 | 82 | --- | 0 | --- | 0 |
Willkommia sarmentosa | --- | 0 | --- | 0 | --- | 0 | 83 | 73 | --- | 0 | --- | 0 |
Sporobolus ioclados | --- | 0 | --- | 0 | --- | 0 | 83 | 73 | --- | 0 | --- | 0 |
Aristida stipoides | --- | 0 | --- | 0 | --- | 0 | 77 | 64 | --- | 0 | --- | 0 |
Eragrostis viscosa | --- | 0 | --- | 0 | --- | 0 | 71 | 55 | --- | 0 | --- | 0 |
Hirpicium gazanioides | --- | 0 | --- | 0 | --- | 0 | 71 | 55 | --- | 0 | --- | 0 |
Dactyloctenium aegyptium | --- | 0 | --- | 0 | --- | 67 | 66 | 91 | --- | 0 | --- | 0 |
Sesuvium sesuvioides | --- | 0 | --- | 0 | --- | 0 | 57 | 36 | --- | 0 | --- | 0 |
Ipomoea coptica | --- | 0 | --- | 0 | --- | 0 | 57 | 36 | --- | 0 | --- | 0 |
Cyperus atriceps | --- | 0 | --- | 0 | --- | 0 | 57 | 36 | --- | 0 | --- | 0 |
Commelina subulata | --- | 0 | --- | 0 | --- | 0 | 57 | 36 | --- | 0 | --- | 0 |
Blepharis leendertziae | --- | 0 | --- | 0 | --- | 0 | 57 | 36 | --- | 0 | --- | 0 |
Sericorema sericea | --- | 0 | --- | 0 | --- | 0 | 52 | 45 | --- | 0 | --- | 17 |
Eragrostis trichophora | --- | 0 | --- | 0 | --- | 0 | 52 | 45 | --- | 0 | --- | 17 |
Microchloa caffra | --- | 0 | --- | 0 | --- | 0 | 49 | 55 | --- | 20 | --- | 17 |
Xerophyta humilis | --- | 0 | --- | 0 | --- | 0 | 49 | 27 | --- | 0 | --- | 0 |
Ophioglossum lancifolium | --- | 0 | --- | 0 | --- | 0 | 49 | 27 | --- | 0 | --- | 0 |
Themeda triandra | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 100 | 100 | --- | 0 |
Elionurus muticus | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 81 | 70 | --- | 0 |
Eragrostis lehmanniana | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 81 | 70 | --- | 0 |
Hilliardiella oligocephala | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 77 | 90 | --- | 33 |
Ipomoea oblongata | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 75 | 60 | --- | 0 |
Hypoxis iridifolia | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 71 | 70 | --- | 17 |
Eragrostis superba | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 71 | 70 | --- | 17 |
Hermannia depressa | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 67 | 50 | --- | 0 |
Corchorus asplenifolius | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 67 | 50 | --- | 0 |
Hermannia eenii | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 67 | 50 | --- | 0 |
Wahlenbergia undulata | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 60 | 40 | --- | 0 |
Solanum delagoense | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 60 | 40 | --- | 0 |
Lantana angolensis | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 60 | 40 | --- | 0 |
Hyparrhenia hirta | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 60 | 40 | --- | 0 |
Convolvulus sagittatus | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 60 | 40 | --- | 0 |
Hibiscus trionum | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 60 | 40 | --- | 0 |
Pollichia campestris | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 55 | 50 | --- | 17 |
Andropogon gayanus var. polycladus | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 55 | 50 | --- | 17 |
Cymbopogon caesius | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 55 | 60 | --- | 33 |
Solanum lichtensteinii | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 55 | 60 | --- | 33 |
Osteospermum muricatum | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 51 | 30 | --- | 0 |
Alternanthera pungens | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 51 | 30 | --- | 0 |
Urochloa oligotricha | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 51 | 30 | --- | 0 |
Listia heterophylla | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 51 | 30 | --- | 0 |
Indigofera vicioides | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 51 | 30 | --- | 0 |
Cynodon dactylon | --- | 0 | --- | 0 | --- | 33 | --- | 18 | 50 | 70 | --- | 17 |
Setaria pumila | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 47 | 40 | --- | 17 |
Euphorbia inaequilatera | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 47 | 40 | --- | 17 |
Urochloa brachyura | --- | 0 | --- | 0 | --- | 0 | --- | 18 | 46 | 50 | --- | 17 |
Fingerhuthia africana | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 10 | 94 | 100 |
Cymbopogon pospischilii | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 40 | 81 | 100 |
Geigeria otaviensis | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 79 | 67 |
Helichrysum cerastioides var. aurosicum | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 79 | 67 |
Jamesbrittenia atropurpurea subsp. pubescens | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 79 | 67 |
Melhania virescens | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 79 | 67 |
Striga bilabiata | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 79 | 67 |
Dicoma anomala | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 79 | 67 |
Eriocephalus luederitzianus | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 79 | 67 |
Brachiaria serrata | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 20 | 78 | 83 |
Scabiosa columbaria | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 10 | 72 | 67 |
Anginon streyi | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 67 | 50 |
Eragrostis nindensis | --- | 0 | --- | 0 | --- | 0 | --- | 18 | --- | 0 | 67 | 67 |
Tarchonanthus camphoratus | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 40 | 57 | 67 |
Rhynchosia totta | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 54 | 33 |
Hibiscus caesius | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 54 | 33 |
Kohautia aspera | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 54 | 33 |
Euphorbia spartaria | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 54 | 33 |
Lagarosiphon muscoides | 54 | 75 | 45 | 67 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Heteropogon contortus | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 49 | 80 | 68 | 100 |
Tragus racemosus | --- | 0 | --- | 0 | --- | 33 | 39 | 45 | --- | 10 | --- | 0 |
Dichrostachys cinerea | --- | 0 | --- | 0 | --- | 0 | --- | 18 | --- | 30 | --- | 17 |
Schkuhria pinnata | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 38 | 40 | --- | 33 |
Oxalis depressa | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 38 | 40 | --- | 33 |
Aristida effusa | --- | 0 | --- | 0 | --- | 33 | --- | 0 | --- | 20 | --- | 33 |
Tragus berteronianus | --- | 0 | --- | 0 | --- | 0 | --- | 9 | --- | 30 | --- | 17 |
Kyllinga alba | --- | 0 | --- | 0 | --- | 0 | --- | 18 | --- | 30 | --- | 0 |
Nidorella resedifolia | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 30 | --- | 33 |
Eragrostis echinochloidea | --- | 0 | --- | 0 | --- | 33 | --- | 0 | --- | 10 | --- | 33 |
Bulbostylis hispidula | --- | 0 | --- | 0 | --- | 0 | --- | 27 | --- | 0 | --- | 17 |
Melinis repens subsp. grandiflora | --- | 0 | --- | 0 | --- | 0 | --- | 9 | --- | 20 | --- | 17 |
Aristida adscensionis | --- | 0 | --- | 0 | --- | 0 | --- | 18 | --- | 20 | --- | 0 |
Brachiaria nigropedata | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 30 | --- | 17 |
Anthephora pubescens | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 30 | --- | 17 |
Euclea undulata | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 30 | --- | 17 |
Vachellia reficiens / luederitzii | --- | 25 | --- | 0 | --- | 0 | --- | 0 | --- | 10 | --- | 17 |
Aristida rhiniochloa | --- | 0 | --- | 0 | --- | 33 | --- | 0 | --- | 10 | --- | 17 |
Gisekia africana | --- | 0 | --- | 0 | --- | 0 | --- | 18 | --- | 0 | --- | 17 |
Aristida meridionalis | --- | 0 | --- | 0 | --- | 0 | --- | 18 | --- | 0 | --- | 17 |
Indigofera charlieriana | --- | 0 | --- | 0 | --- | 0 | --- | 9 | --- | 10 | --- | 17 |
Tephrosia dregeana var. dregeana | --- | 0 | --- | 0 | --- | 0 | --- | 9 | --- | 20 | --- | 0 |
Pogonarthria fleckii | --- | 0 | --- | 0 | --- | 0 | --- | 18 | --- | 0 | --- | 17 |
Ziziphus mucronata | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 20 | --- | 17 |
Monsonia glauca | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 20 | --- | 17 |
Commelina livingstonii | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 20 | --- | 17 |
Aristida congesta subsp. congesta | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 20 | --- | 17 |
Thesium xerophyticum | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 10 | --- | 33 |
Panicum coloratum | --- | 25 | --- | 0 | --- | 0 | --- | 0 | --- | 10 | --- | 0 |
Vahlia capensis | --- | 0 | --- | 33 | --- | 0 | --- | 9 | --- | 0 | --- | 0 |
Overview of the ephemeral wetlands:
1.1 Undefined upper hierarchy
1.1.1.1 Nymphoides indica-Echinochloa pyramidalis community
1.1.1.2 Panicum gilvum-Marsilea nubica community
1.1.1.1 Nymphoides indica - Echinochloa pyramidalis community
Number of relevés: 4
Number of species observed: 22
Estimated number of species: 34
Average species density in 1000 m2: 9
Diagnostic species: Nymphoides indica subsp. occidentalis, Eragrostis rotifer, Nymphaea nouchali var. caerulea, Echinochloa pyramidalis, Cyperus compressus, Lagarosiphon muscoides
These vleys occur embedded in the Omuramba Ovambo, surrounded by a fringe of Terminalio prunioidis–Spirostachyetum africanae (see 5.2.3.1). The vley vegetation is dominated by the aquatic plants Lagarosiphon muscoides, Eragrostis rotifer, Echinochloa pyramidalis, Schoenoplectus corymbosus, Nymphoides indica subsp. occidentalis, Leptochloa fusca and Echinochloa crus-galli. The presence of the geophytic hydrophyte Nymphaea nouchali indicates that these vleys are generally deeper (about 1 m or more), and regularly filled with water, allowing this species to survive. Similar vleys have been found to the east in the Maroelaboom Dune Belt and the Tsumkwe district (
Typical structure of the associations of the wet- and grasslands: (a) Nymphoides indica–Echinochloa pyramidalis community; (b) Panicum gilvum–Marsilea nubica community; (c) Sporobolus spicatus–Odyssea paucinervis community; (d) Aristido stipoidis-Willkommietum sarmentosae; (e) Hilliardiello oligocephalae-Themedetum triandrae; (f) Geigerio otaviensis-Fingerhuthietum africanae.
Typical views of the associations of the wet- and grasslands: (a) Example of the Nymphoides indica-Echinochloa pyramidalis community, relevé 4097, ca 50 km east of the study area; (b) Panicum gilvum-Marsilea nubica community, relevé 7776; (c) Aristido stipoidis-Willkommietum sarmentosae, relevé 7773, foreground. In the background is a Terminalio prunioidis-Spirostachyetum africanae island; (d) Hilliardiello oligocephalae-Themedetum triandrae, relevé 7947; (e) Geigerio otaviensis-Fingerhuthietum africanae, relevé 7960; (f) soil surface of the Geigerio otaviensis-Fingerhuthietum africanae habitat at relevé 7960.
1.1.1.2 Panicum gilvum-Marsilea nubica community
Number of relevés: 3
Number of species observed: 14
Estimated number of species: 20
Average species density in 1000 m2: 7
Diagnostic species: Panicum gilvum, Marsilea nubica, Lapeirousia avasmontana, Combretum imberbe, Lagarosiphon muscoides
The Panicum gilvum-Marsilea nubica community is found in feeder streams to the Omuramba Ovambo system, and is dominated by the aquatic species Marsilea nubica, Marsdenia macrantha and Lagarosiphon muscoides. A similar association has been described by
Grasslands are limited in extent in Namibia and are often associated with wetland systems or desert environments. Within the study area, these are dominated by the plant families Poaceae (65 species), Fabaceae (22 species) and Asteraceae (21 species). Two higher order groupings could be recognised, but at this stage are not formally described, pending an extensive revision of these grasslands in comparison to other similar types in Namibia, as well as in the South African Grassland Biome (
Overview of the grassland groupings:
2.1 Undefined upper hierarchy
2.1.1 Ishana grasslands (Sporobolus-dominated)
2.1.1.1 Sporobolus spicatus-Odyssea paucinervis community
2.1.1.2 Aristido stipoidis-Willkommietum sarmentosae
2.1.2 Mesic grasslands
2.1.2.1 Hilliardiello oligocephalae-Themedetum triandrae
2.1.2.2 Geigerio otaviensis-Fingerhuthietum africanae
2.1.1 Ishana grasslands (Sporobolus-dominated)
The Sporobolus-dominated grasslands are associated with pans and shallow water courses, typically the ishana and pans of the Cuvelai Delta (
2.1.1.1 Sporobolus spicatus-Odyssea paucinervis community
Number of relevés: 3
Number of species observed: 10
Estimated number of species: 13
Average species density in 1000 m2: 6
Diagnostic species: Sporobolus spicatus, Leptochloa fusca, Odyssea paucinervis, Sporobolus acinifolius
Constant species: Dactyloctenium aegyptium
Along the eastern fringe of the Omuramba Ovambo, on the farm Nukuwis, occurs an isolated clay pan. The pan is zoned in three concentric zones: The outer ring is a mixture of Sporobolus spicatus, with some Odyssea paucinervis and Cynodon dactylon, the following ring is dominated by Leptochloa fusca, whilst the inner ring is dominated by Sporobolus acinifolius. In the centre is a bare patch. The structure is best described as a low, open grassland (Figure
The soils consist of a heavy, whitish clay with 73% clay in the topsoil, increasing to 83% in the B-horizon. The pH ranged between 9.8 to 10.0, with the soil conductivity ranging between 4,700 to 6,480 µS/cm. Sodium content of the soils was 12,200 ppm. The high salinity is reflected in the presence of Odyssea paucinervis (
2.1.1.2 Aristido stipoidis-Willkommietum sarmentosae ass. nov.
Number of relevés: 11
Number of species observed: 67
Estimated number of species: 99
Average species density in 1000 m2: 16
Type relevé: 2781 (holotypus), sampled on 2 April 2003 at 19.17861°S, 18.61083°E (Begus)
Hyphaene petersiana (t2) 0.1%, Hyphaene petersiana (s1) 1%, Eragrostis trichophora (gp) 10%, Willkommia sarmentosa (gp) 10%, Sporobolus ioclados (gp) 5%, Odyssea paucinervis (gp) 2%, Microchloa caffra (gp) 1%, Aristida stipoides (ga) 2%, Eragrostis viscosa (ga) 2%, Chloris virgata (ga) 1%, Dactyloctenium aegyptium (ga) 1%, Pogonarthria fleckii (ga) 1%, Commelina erecta (hl) 1%, Hirpicium gazanioides (hl) 1%, Kyllinga alba (hl) 1%, Portulaca kermesina (hl) 1%, Sesuvium sesuvioides (hl) 1%
Diagnostic species: Chloris virgata, Willkommia sarmentosa, Sporobolus ioclados, Aristida stipoides, Hirpicium gazanioides, Eragrostis viscosa, Dactyloctenium aegyptium, Sesuvium sesuvioides, Ipomoea coptica, Cyperus atriceps, Commelina subulata, Blepharis leendertziae, Sericorema sericea, Eragrostis trichophora, Microchloa caffra, Xerophyta humilis, Ophioglossum lancifolium
The Aristido stipoidis-Willkommietum sarmentosae form the matrix of the Omuramba Ovambo vegetation, being the typical short open grasslands of the ‘Parkiesveld’ (Figures
The A-horizon is about 10 cm deep and consists of a near-pure, white sand (94% sand and 5% clay), with a pH of 7.3 and an electric conductivity of 49 µS/cm. The B-horizon is slightly loamier with 7% clay and 92% sand and has a pH of 9.7. The steeply increased electric conductivity (1117 µS/cm) is due to sodium and calcium collecting in this horizon (1380 ppm Na and 1322 ppm Ca). The horizon has also a gleyic, mottled appearance. The Aristido stipoidis-Willkommietum sarmentosae occur at an altitudinal range of between 1164 and 1201 m a.s.l.
a Aerial image showing the mosaic of vegetation associations. (a) A portion of the Omuramba Ovambo at the farm Nukuwis. Alternatively to the Terminalietum sericeo-prunioidis, the Combreto apiculati-Terminalietum prunioidis can surround this mosaic, depending on the depth of the Kalahari sand cover. (b) The central Otavi mountains north of Kombat. The mountains are covered by one of the three associations of the Commiphoro glaucescentis- Kirkietalia acuminatae, depending on steepness and massiveness of the rocks, whilst the light-coloured bands on top of the mountains represent the Auros shales with a cover of Geigerio otaviensis-Fingerhuthietum africanae. Image source: Microsoft Maps (Bing Maps).
2.1.2 Mesic grasslands
The Mesic grasslands found within the Karstveld resemble the Grassland Biome in South Africa, in particular the Highveld Mesic Grasslands (
2.1.2.1 Hilliardiello oligocephalae - Themedetum triandrae ass. nov.
Number of relevés: 10
Number of species observed: 115
Estimated number of species: 177
Average species density in 1000 m2: 30
Type relevé: 7953 (holotypus), sampled on 18 February 2008 at 19.63861°S, 17.77306°E (Neu Sommerau)
Heteropogon contortus (gp) 20%, Brachiaria nigropedata (gp) 10%, Elionurus muticus (gp) 10%, Themeda triandra (gp) 10%, Anthephora pubescens (gp) 5%, Cymbopogon pospischilii (gp) 2%, Andropogon gayanus (gp) 1%, Brachiaria serrata (gp) 1%, Cymbopogon caesius (gp) 1%, Eragrostis lehmanniana var. lehmanniana (gp) 1%, Microchloa caffra (gp) 0.5%, Hilliardiella oligocephala (hl) 2%, Thesium xerophyticum (hl) 2%, Clematis villosa subsp. villosa (hl) 1%, Hypoxis iridifolia (hl) 1%, Ipomoea oblongata (hl) 1%, Scabiosa columbaria (hl) 1%, Chamaecrista mimosoides (hl) 0.5%, Corchorus asplenifolius (hl) 0.5%, Hermannia eenii (hl) 0.5%, Tephrosia dregeana var. dregeana (hl) 0.5%
Diagnostic species: Themeda triandra, Eragrostis lehmanniana, Elionurus muticus, Hilliardiella oligocephala, Ipomoea oblongata, Hypoxis iridifolia, Eragrostis superba, Hermannia eenii, Hermannia depressa, Corchorus asplenifolius, Wahlenbergia undulata, Solanum delagoense, Lantana angolensis, Hyparrhenia hirta, Hibiscus trionum, Convolvulus sagittatus, Pollichia campestris, Andropogon gayanus var. polycladus, Solanum lichtensteinii, Cymbopogon caesius, Urochloa oligotricha, Osteospermum muricatum, Listia heterophylla, Indigofera vicioides, Alternanthera pungens, Cynodon dactylon, Heteropogon contortus, Setaria pumila, Euphorbia inaequilatera, Urochloa brachyura
The Hilliardiello oligocephalae-Themedetum triandrae forms a tall, closed grassland very similar to the Highveld Grasslands of the central and eastern Grassland Biome in South Africa (
The Hilliardiello oligocephalae-Themedetum triandrae occur in intermontane valleys filled with deep red soils derived from phyllites of the Mulden Group. They occur at altitudes between 1460 and 1860 m a.s.l., on gently undulating, undulating and rolling slopes. No obvious stone cover has been observed. Next to bush encroachment and erosion, these grasslands are threatened by tillage for crop production. Most of the original vegetation in the Otavi valley has been transformed in this way; only in the Sommerau – Gauss valley north of Kombat pristine examples were found.
2.1.2.2 Geigerio otaviensis - Fingerhuthietum africanae ass. nov.
Number of relevés: 6
Number of species observed: 89
Estimated number of species: 140
Average species density in 1000 m2: 27
Type relevé: 7960 (holotypus), sampled on 19 February 2008 at 19.57389°S, 17.70111°E (Gauss)
Helichrysum cerastioides var. aurosicum (s2) 1%, Amphiglossa triflora (s2) 0.5%, Eriocephalus luederitzianus (s2) 0.5%, Jamesbrittenia atropurpurea subsp. pubescens (s2) 0.5%, Tarchonanthus camphoratus (s2) 0.5%, Fingerhuthia africana (gp) 20%, Cymbopogon pospischilii (gp) 10%, Heteropogon contortus (gp) 10%, Brachiaria serrata (gp) 5%, Eragrostis nindensis (gp) 1%, Geigeria otaviensis (hl) 1%, Striga bilabiata (hl) 1%, Dicoma anomala (hl) 0.5%, Scabiosa columbaria (hl) 0.5%, Anginon streyi (hl) 0.1
Diagnostic species: Fingerhuthia africana, Cymbopogon pospischilii, Striga bilabiata, Melhania virescens, Jamesbrittenia atropurpurea subsp. pubescens, Helichrysum cerastioides var. aurosicum, Geigeria otaviensis, Eriocephalus luederitzianus, Dicoma anomala, Brachiaria serrata, Scabiosa columbaria, Heteropogon contortus, Eragrostis nindensis, Anginon streyi, Tarchonanthus camphoratus, Rhynchosia totta, Kohautia aspera, Hibiscus caesius, Euphorbia spartaria
The Geigerio otaviensis–Fingerhuthietum africanae forms a short, moderately closed grassland dominated by Heteropogon contortus, Cymbopogon pospischilii and Fingerhuthia africana (Figures
The southern Karstveld vegetation transitions into the Thornbush savanna sensu
Abbreviated synoptic table for the Thornbush savanna - Karstveld transition, showing all species occurring in more than 10% of relevés of this group, with fidelity (phi coefficient × 100) and frequency of occurrence (%).
Association | 3.1.1.1 | 3.1.1.2 | 3.1.1.3 | 3.1.1.4 | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Subassociation | 3.1.1.3.1 | 3.1.1.3.2 | ||||||||
No of relevés | 93 | 56 | 71 | 145 | 32 | |||||
Species | phi | % | phi | % | phi | % | phi | % | phi | % |
Brachiaria nigropedata | 59 | 54 | --- | 5 | --- | 0 | --- | 1 | --- | 6 |
Anthephora pubescens | 53 | 87 | --- | 7 | --- | 1 | --- | 23 | 27 | 63 |
Sesamum triphyllum | 51 | 45 | --- | 2 | --- | 0 | --- | 3 | --- | 9 |
Rotheca myricoides | 51 | 39 | --- | 0 | --- | 0 | --- | 1 | --- | 6 |
Schmidtia pappophoroides | 49 | 78 | --- | 34 | --- | 7 | --- | 23 | --- | 19 |
Vernonia fastigiata | 48 | 37 | --- | 4 | --- | 3 | --- | 2 | --- | 0 |
Dicoma anomala | 46 | 38 | --- | 2 | --- | 0 | --- | 1 | --- | 9 |
Ozoroa paniculosa | 43 | 68 | --- | 34 | --- | 3 | --- | 17 | --- | 22 |
Tragus racemosus | 43 | 68 | --- | 4 | --- | 7 | --- | 19 | 20 | 47 |
Triraphis purpurea | 42 | 37 | --- | 2 | --- | 4 | --- | 7 | --- | 3 |
Indigofera charlieriana | 42 | 66 | --- | 4 | --- | 7 | --- | 20 | 18 | 44 |
Indigofera pechuelii | 40 | 20 | --- | 0 | --- | 0 | --- | 1 | --- | 0 |
Hermannia eenii | --- | 5 | 58 | 54 | --- | 6 | --- | 3 | --- | 0 |
Aristida pilgeri | --- | 5 | 55 | 43 | --- | 0 | --- | 1 | --- | 0 |
Melhania acuminata | --- | 2 | 55 | 54 | --- | 4 | --- | 11 | --- | 3 |
Vachellia erioloba | --- | 6 | 49 | 57 | --- | 14 | --- | 12 | --- | 3 |
Terminalia sericea | --- | 0 | 49 | 30 | --- | 0 | --- | 1 | --- | 0 |
Senegalia cinerea | --- | 4 | 47 | 59 | --- | 20 | --- | 12 | --- | 9 |
Dicoma schinzii | --- | 15 | 45 | 45 | --- | 1 | --- | 5 | --- | 3 |
Waltheria indica | --- | 9 | 43 | 50 | --- | 4 | --- | 17 | --- | 6 |
Digitaria seriata | --- | 0 | 41 | 29 | --- | 1 | --- | 3 | --- | 3 |
Heliotropium nelsonii | --- | 3 | --- | 0 | 52 | 48 | --- | 11 | --- | 3 |
Leucosphaera bainesii | --- | 2 | --- | 0 | 52 | 45 | --- | 12 | --- | 0 |
Monechma genistifolium | --- | 0 | --- | 0 | 51 | 37 | --- | 5 | --- | 0 |
Ipomoea obscura var. obscura | --- | 1 | --- | 2 | 49 | 35 | --- | 3 | --- | 0 |
Asparagus cooperi | --- | 0 | --- | 0 | 46 | 30 | --- | 4 | --- | 0 |
Eragrostis porosa | --- | 4 | --- | 2 | 43 | 48 | --- | 14 | --- | 13 |
Solanum tettense var. renschii | --- | 0 | --- | 2 | 43 | 34 | --- | 7 | --- | 3 |
Hibiscus calyphyllus | --- | 0 | --- | 2 | 42 | 35 | --- | 10 | --- | 3 |
Geigeria acaulis | --- | 0 | --- | 2 | 41 | 23 | --- | 0 | --- | 0 |
Boscia albitrunca | --- | 0 | --- | 9 | 41 | 48 | --- | 16 | --- | 13 |
Hibiscus palmatus | --- | 0 | --- | 0 | 41 | 23 | --- | 2 | --- | 0 |
Ptycholobium biflorum subsp. angolensis | --- | 3 | --- | 0 | 40 | 42 | --- | 19 | --- | 6 |
Corchorus tridens | --- | 3 | --- | 0 | 63 | 58 | --- | 9 | --- | 0 |
Olea europaea subsp. africana | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 100 | 100 |
Fingerhuthia africana | 30 | 74 | --- | 4 | --- | 7 | --- | 47 | 46 | 91 |
Digitaria eriantha | --- | 1 | --- | 0 | --- | 0 | --- | 5 | 45 | 31 |
Euclea undulata | 21 | 62 | --- | 21 | --- | 3 | --- | 39 | 43 | 84 |
Croton gratissimus | --- | 3 | --- | 7 | --- | 14 | 22 | 46 | 41 | 63 |
Kohautia aspera | --- | 10 | --- | 4 | --- | 0 | --- | 8 | 40 | 38 |
Heteropogon contortus | 28 | 81 | --- | 27 | --- | 8 | --- | 59 | 38 | 91 |
Senegalia mellifera subsp. detinens | --- | 88 | --- | 89 | --- | 87 | 9 | 97 | --- | 97 |
Dichrostachys cinerea | --- | 77 | 13 | 88 | --- | 77 | --- | 76 | --- | 66 |
Grewia flava | --- | 73 | --- | 61 | --- | 73 | --- | 76 | --- | 66 |
Combretum hereroense | 24 | 85 | --- | 55 | --- | 10 | 18 | 79 | 20 | 81 |
Vachellia reficiens / luederitzii | --- | 29 | --- | 68 | 21 | 87 | --- | 69 | 21 | 88 |
Eragrostis trichophora | --- | 68 | --- | 45 | 21 | 80 | --- | 52 | --- | 56 |
Tarchonanthus camphoratus | 30 | 85 | --- | 21 | --- | 39 | --- | 63 | --- | 66 |
Stipagrostis uniplumis var. uniplumis | 17 | 75 | 22 | 80 | --- | 42 | --- | 50 | --- | 47 |
Melhania virescens | --- | 65 | --- | 7 | --- | 48 | 15 | 70 | 32 | 88 |
Lantana angolensis | --- | 59 | --- | 41 | --- | 51 | --- | 59 | --- | 69 |
Urochloa brachyura | 16 | 67 | --- | 50 | --- | 45 | --- | 50 | --- | 41 |
Seddera suffruticosa | 21 | 71 | --- | 16 | --- | 41 | --- | 57 | --- | 66 |
Ziziphus mucronata | --- | 51 | --- | 59 | --- | 39 | --- | 50 | 18 | 72 |
Melinis repens subsp. grandiflora | 23 | 70 | --- | 21 | --- | 52 | --- | 47 | --- | 44 |
Enneapogon scoparius | 17 | 61 | --- | 5 | --- | 24 | 16 | 60 | 28 | 72 |
Otoptera burchellii | 16 | 60 | --- | 23 | 14 | 58 | --- | 43 | --- | 38 |
Eragrostis echinochloidea | --- | 25 | --- | 9 | --- | 51 | 20 | 66 | 33 | 78 |
Cenchrus ciliaris | --- | 23 | --- | 4 | 29 | 75 | 12 | 57 | 24 | 69 |
Searsia marlothii | 10 | 56 | --- | 21 | --- | 10 | 11 | 57 | 39 | 84 |
Combretum imberbe | 31 | 69 | --- | 39 | --- | 6 | --- | 41 | --- | 38 |
Aristida rhiniochloa | 32 | 68 | --- | 21 | --- | 27 | --- | 37 | --- | 31 |
Peltophorum africanum | 18 | 56 | 14 | 52 | --- | 3 | --- | 34 | --- | 47 |
Enneapogon cenchroides | --- | 42 | --- | 7 | 22 | 56 | --- | 36 | --- | 38 |
Aristida effusa | --- | 41 | --- | 9 | --- | 45 | 12 | 44 | --- | 25 |
Grewia flavescens | --- | 9 | --- | 45 | 11 | 49 | 4 | 42 | --- | 47 |
Ocimum americanum var. americanum | --- | 40 | --- | 41 | --- | 32 | --- | 35 | --- | 25 |
Hibiscus caesius | --- | 32 | --- | 11 | --- | 7 | 14 | 45 | 36 | 66 |
Aptosimum decumbens | --- | 37 | --- | 29 | --- | 28 | --- | 30 | --- | 28 |
Ehretia rigida | --- | 10 | --- | 11 | 33 | 59 | 9 | 37 | --- | 28 |
Pogonarthria fleckii | 24 | 52 | --- | 27 | --- | 37 | --- | 17 | --- | 16 |
Sericorema sericea | 24 | 51 | --- | 4 | --- | 10 | --- | 30 | 23 | 50 |
Phyllanthus maderaspatensis | --- | 29 | --- | 18 | --- | 31 | --- | 31 | --- | 31 |
Terminalia prunioides | --- | 12 | --- | 21 | --- | 14 | 28 | 49 | --- | 28 |
Aristida adscensionis | 21 | 45 | --- | 9 | --- | 37 | --- | 22 | --- | 19 |
Aristida congesta subsp. congesta | 24 | 48 | 12 | 38 | --- | 32 | --- | 11 | --- | 6 |
Urochloa oligotricha | 9 | 37 | --- | 4 | --- | 27 | --- | 23 | 27 | 53 |
Evolvulus alsinoides | --- | 12 | 21 | 48 | 18 | 45 | --- | 21 | --- | 19 |
Tragus berteronianus | --- | 31 | --- | 4 | 20 | 42 | --- | 22 | --- | 25 |
Eragrostis nindensis | 15 | 33 | --- | 2 | --- | 10 | 15 | 34 | --- | 28 |
Grewia bicolor | --- | 11 | --- | 21 | 28 | 45 | --- | 26 | --- | 6 |
Limeum sulcatum | 24 | 45 | --- | 5 | --- | 8 | --- | 17 | 26 | 47 |
Tephrosia dregeana var. dregeana | --- | 27 | --- | 29 | --- | 8 | --- | 22 | --- | 31 |
Ocimum filamentosum | --- | 6 | --- | 5 | 21 | 38 | 14 | 32 | --- | 22 |
Pavonia burchellii | --- | 12 | --- | 23 | 12 | 34 | --- | 21 | --- | 28 |
Geigeria ornativa | --- | 8 | --- | 29 | --- | 28 | --- | 26 | --- | 16 |
Commiphora glandulosa | --- | 22 | --- | 18 | --- | 0 | 18 | 33 | --- | 22 |
Nidorella resedifolia | --- | 8 | --- | 13 | 22 | 38 | 9 | 27 | --- | 16 |
Gymnosporia senegalensis | --- | 6 | --- | 16 | --- | 7 | 12 | 33 | 36 | 53 |
Stipagrostis hirtigluma subsp. hirtigluma | --- | 1 | --- | 2 | --- | 20 | 33 | 41 | --- | 19 |
Clerodendrum ternatum | --- | 4 | --- | 18 | 13 | 30 | 12 | 28 | --- | 16 |
Rhynchosia totta | --- | 16 | --- | 14 | --- | 15 | 9 | 26 | --- | 25 |
Searsia ciliata | 32 | 44 | --- | 13 | --- | 10 | --- | 13 | --- | 16 |
Enneapogon desvauxii | --- | 13 | --- | 0 | --- | 11 | 8 | 28 | 40 | 53 |
Kyphocarpa angustifolia | 16 | 33 | 15 | 32 | --- | 24 | --- | 6 | --- | 6 |
Commelina livingstonii | 39 | 49 | --- | 4 | --- | 10 | --- | 10 | --- | 22 |
Catophractes alexandri | --- | 9 | --- | 5 | --- | 17 | 20 | 31 | --- | 19 |
Leucas pechuelii | --- | 4 | --- | 2 | 38 | 44 | 11 | 24 | --- | 6 |
Phyllanthus pentandrus | --- | 8 | --- | 11 | --- | 21 | 5 | 23 | 19 | 34 |
Heliotropium ovalifolium | --- | 9 | --- | 14 | --- | 6 | 3 | 23 | 37 | 50 |
Panicum coloratum | 36 | 45 | --- | 5 | --- | 6 | --- | 8 | --- | 25 |
Eragrostis rigidior | --- | 5 | 26 | 39 | 14 | 30 | --- | 13 | --- | 6 |
Melinis repens subsp. repens | --- | 23 | 20 | 34 | --- | 11 | --- | 11 | --- | 13 |
Eriocephalus luederitzianus | 14 | 26 | --- | 0 | --- | 14 | --- | 19 | --- | 19 |
Commiphora angolensis | --- | 6 | --- | 5 | --- | 23 | 13 | 24 | --- | 16 |
Chascanum pinnatifidum | --- | 12 | --- | 4 | 31 | 35 | --- | 19 | --- | 0 |
Acalypha segetalis | 31 | 39 | --- | 0 | --- | 3 | --- | 12 | --- | 25 |
Commiphora africana | --- | 15 | --- | 0 | --- | 10 | 11 | 23 | 18 | 28 |
Pupalia lappacea | --- | 9 | --- | 5 | 23 | 34 | --- | 14 | --- | 22 |
Combretum apiculatum | 12 | 26 | --- | 11 | --- | 0 | --- | 15 | 20 | 31 |
Rhynchosia minima | 10 | 24 | --- | 2 | --- | 11 | --- | 15 | 17 | 28 |
Pogonarthria squarrosa | 20 | 30 | 35 | 41 | --- | 1 | --- | 6 | --- | 0 |
Eragrostis superba | 37 | 41 | --- | 2 | --- | 3 | --- | 10 | --- | 19 |
Hermannia tomentosa | 26 | 33 | --- | 13 | --- | 8 | --- | 10 | --- | 9 |
Cymbopogon pospischilii | 39 | 44 | --- | 4 | --- | 1 | --- | 6 | --- | 25 |
Helinus spartioides | 19 | 26 | --- | 5 | --- | 11 | --- | 14 | --- | 9 |
Raphionacme lanceolata | --- | 12 | --- | 2 | --- | 21 | --- | 18 | --- | 13 |
Acrotome inflata | --- | 17 | --- | 5 | 22 | 31 | --- | 7 | --- | 16 |
Solanum lichtensteinii | 12 | 23 | --- | 2 | 18 | 27 | --- | 7 | --- | 13 |
Aristida stipoides | 35 | 37 | --- | 0 | --- | 3 | --- | 8 | --- | 19 |
Sida ovata | --- | 4 | 25 | 32 | --- | 13 | --- | 13 | --- | 9 |
Andropogon gayanus var. polycladus | 32 | 35 | --- | 7 | --- | 0 | --- | 6 | --- | 19 |
Eragrostis lehmanniana | --- | 2 | 31 | 34 | --- | 0 | 10 | 19 | --- | 9 |
Gisekia africana | 26 | 31 | --- | 7 | --- | 3 | --- | 7 | --- | 19 |
Andropogon chinensis | 30 | 32 | --- | 2 | --- | 3 | --- | 7 | --- | 19 |
Brachiaria deflexa | --- | 6 | --- | 0 | 19 | 25 | --- | 12 | --- | 19 |
Albizia anthelmintica | --- | 2 | --- | 5 | 31 | 30 | --- | 15 | --- | 0 |
Bothriochloa radicans | --- | 5 | --- | 2 | --- | 11 | 24 | 22 | --- | 3 |
Mundulea sericea | --- | 5 | --- | 2 | --- | 1 | 12 | 20 | 30 | 31 |
Commiphora pyracanthoides | --- | 0 | --- | 2 | 37 | 34 | --- | 13 | --- | 6 |
Pentarrhinum insipidum | 8 | 19 | --- | 5 | --- | 3 | --- | 8 | 30 | 34 |
Hyphaene petersiana | --- | 13 | 27 | 27 | --- | 1 | --- | 11 | --- | 0 |
Oxygonum alatum | --- | 12 | --- | 7 | 14 | 21 | --- | 7 | --- | 13 |
Commelina benghalensis | --- | 2 | --- | 5 | 34 | 34 | --- | 8 | --- | 9 |
Ruellia species | --- | 1 | --- | 0 | 30 | 27 | 11 | 16 | --- | 3 |
Aizoon virgatum | --- | 0 | --- | 0 | 32 | 30 | --- | 14 | --- | 6 |
Monechma spartioides | --- | 0 | 27 | 30 | --- | 6 | --- | 12 | --- | 16 |
Hermannia modesta | --- | 11 | --- | 2 | 24 | 27 | --- | 6 | --- | 13 |
Sporobolus panicoides | --- | 4 | --- | 4 | --- | 4 | 8 | 17 | 26 | 28 |
Philenoptera nelsii | --- | 0 | 23 | 27 | 27 | 30 | --- | 4 | --- | 0 |
Cyperus palmatus | 26 | 27 | --- | 0 | --- | 11 | --- | 3 | --- | 13 |
Brachiaria malacodes | 11 | 16 | --- | 0 | --- | 14 | --- | 9 | --- | 9 |
Indigofera daleoides | 36 | 31 | --- | 14 | --- | 1 | --- | 2 | --- | 0 |
Kohautia caespitosa subsp. brachyloba | 11 | 17 | --- | 2 | 22 | 24 | --- | 3 | --- | 6 |
Vachellia hebeclada subsp. hebeclada | --- | 5 | --- | 13 | 31 | 30 | --- | 5 | --- | 0 |
Euphorbia inaequilatera | --- | 9 | --- | 0 | 21 | 24 | --- | 7 | --- | 16 |
Ruelliopsis damarensis | --- | 11 | --- | 4 | --- | 15 | --- | 9 | --- | 13 |
Talinum arnotii | --- | 3 | --- | 7 | 39 | 32 | --- | 6 | --- | 0 |
Sporobolus fimbriatus | --- | 2 | 16 | 20 | --- | 8 | --- | 11 | --- | 9 |
Tinnea rhodesiana | 19 | 16 | --- | 0 | --- | 0 | 15 | 14 | --- | 3 |
Senegalia hereroensis | 15 | 22 | --- | 0 | --- | 1 | --- | 4 | 31 | 31 |
Ipomoea bolusiana | --- | 4 | --- | 16 | --- | 7 | --- | 12 | --- | 3 |
Peliostomum leucorrhizum | --- | 1 | --- | 0 | 35 | 27 | --- | 12 | --- | 0 |
Hermannia quartiniana | --- | 5 | --- | 13 | --- | 6 | --- | 10 | --- | 16 |
Aristida meridionalis | 31 | 26 | --- | 14 | --- | 0 | --- | 2 | --- | 0 |
Pechuel-Loeschea leubnitziae | --- | 5 | --- | 11 | 11 | 15 | --- | 8 | --- | 6 |
Antiphiona pinnatisecta | 12 | 17 | --- | 5 | --- | 0 | --- | 6 | 20 | 22 |
Monechma divaricatum | --- | 1 | --- | 5 | --- | 7 | 21 | 17 | --- | 3 |
Achyranthes aspera var. sicula | --- | 8 | --- | 0 | 13 | 17 | --- | 7 | --- | 16 |
Dicoma tomentosa | --- | 3 | --- | 9 | 15 | 18 | --- | 7 | --- | 9 |
Solanum delagoense | --- | 3 | --- | 5 | --- | 8 | 15 | 14 | --- | 3 |
Ipomoea sinensis | --- | 5 | --- | 0 | 30 | 23 | --- | 8 | --- | 0 |
Tribulus terrestris | --- | 1 | --- | 0 | 25 | 20 | --- | 11 | --- | 3 |
Bidens biternata | --- | 6 | --- | 2 | --- | 6 | --- | 8 | 34 | 31 |
Bulbostylis hispidula | 10 | 14 | --- | 7 | --- | 11 | --- | 3 | --- | 6 |
Hermbstaedtia odorata | 22 | 19 | --- | 4 | --- | 4 | --- | 5 | --- | 6 |
Helinus integrifolius | --- | 8 | --- | 0 | 26 | 21 | --- | 6 | --- | 3 |
Hypoestes forskaolii | --- | 0 | --- | 0 | --- | 7 | 14 | 15 | --- | 16 |
Setaria verticillata | --- | 8 | --- | 0 | 11 | 14 | --- | 7 | --- | 13 |
Chloris virgata | --- | 9 | --- | 0 | 26 | 20 | --- | 6 | --- | 0 |
Petalidium englerianum | --- | 2 | --- | 0 | --- | 6 | 20 | 15 | --- | 6 |
Aloe zebrina | 9 | 13 | --- | 13 | --- | 0 | --- | 6 | --- | 9 |
Overview of the Thornbush savannah – Karst transition syntaxa:
3.1 Undefined upper hierarchy
3.1.1.1 Combreto hereroense-Tarchonanthoetum camphorate
3.1.1.2 Aristido pilgeri-Vachellietum eriolobae
3.1.1.3 Cenchro ciliaris-Senegalietum detinentis
3.1.1.3.1 Cenchro ciliaris-Senegalietum detinentis typicum
3.1.1.3.2 Cenchro ciliaris-Senegalietum detinentis stipagrostietosum hirtiglumae
3.1.1.4 Eucleo undulatae-Oleetum africanae
3.1.1.1 Combreto hereroense-Tarchonanthoetum camphorati ass. nov.
Number of relevés: 93
Number of species observed: 226
Estimated number of species: 368
Average species density in 1000 m2: 48
Type relevé: 4318 (holotypus), sampled on 19 March 1997 at 19.69361°S, 18.05528°E (John Pandeni Research Station / Gressenhof)
Combretum hereroense (s1) 5%, Tarchonanthus camphoratus (s1) 5%, Senegalia mellifera subp. detinens (s1) 2%, Senegalia cinerea (s1) 0.1%, Ziziphus mucronata (s1) 0.1%, Grewia flava (s2) 1%, Dichrostachys cinerea (s2) 0.3%, Euclea undulata (s2) 0.3%, Ozoroa paniculosa (s2) 0.3%, Searsia ciliata (s2) 0.3%, Grewia bicolor (s2) 0.1%, Lantana angolensis (s2) 0.1%, Anthephora pubescens (gp) 1%, Aristida congesta subsp. congesta (gp) 1%, Brachiaria nigropedata (gp) 1%, Schmidtia pappophoroides (gp) 1%, Andropogon gayanus (gp) 0.3%, Cymbopogon pospischilii (gp) 0.3%, Fingerhuthia africana (gp) 0.3%, Heteropogon contortus (gp) 0.3%, Panicum coloratum (gp) 0.3%, Pogonarthria squarrosa (gp) 0.3%, Stipagrostis uniplumis var. uniplumis (gp) 0.3%, Aristida rhiniochloa (ga) 60%, Pogonarthria fleckii (ga) 2%, Urochloa brachyura (ga) 1%, Aristida adscensionis (ga) 0.3%, Aristida effusa (ga) 0.3%, Aristida stipoides (ga) 0.3%, Tragus berteronianus (ga) 0.3%, Tragus racemosus (ga) 0.3%, Triraphis purpurea (ga) 0.3%, Eustachys paspaloides (ga) 0.1%, Indigofera charlieriana (hl) 1%, Bulbostylis hispidula (hl) 0.3%, Cyperus palmatus (hl) 0.3%, Dicoma anomala (hl) 0.3%, Hermannia tomentosa (hl) 0.3%, Indigofera pechuelii (hl) 0.3%, Kyphocarpa angustifolia (hl) 0.3%, Limeum sulcatum (hl) 0.3%, Melhania virescens (hl) 0.3%, Otoptera burchellii (hl) 0.3%, Rotheca myricoides (hl) 0.3%, Seddera suffruticosa (hl) 0.3%, Sesamum triphyllum (hl) 0.3%, Acalypha segetalis (hl) 0.1%, Aptosimum decumbens (hl) 0.1%, Euphorbia inaequilatera (hl) 0.1%, Geigeria ornativa (hl) 0.1%, Hibiscus caesius (hl) 0.1%, Pentarrhinum insipidum (hl) 0.1%, Trochomeria macrocarpa subsp. vitifolia (hl) 0.1%
Diagnostic species: Brachiaria nigropedata, Anthephora pubescens, Sesamum triphyllum, Rotheca myricoides, Schmidtia pappophoroides, Vernonia fastigiata, Dicoma anomala, Ozoroa paniculosa, Tragus racemosus, Triraphis purpurea, Indigofera charlieriana, Indigofera pechuelii
Constant species: Senegalia mellifera subsp. detinens, Tarchonanthus camphoratus, Combretum hereroense, Heteropogon contortus, Dichrostachys cinerea, Stipagrostis uniplumis var. uniplumis, Fingerhuthia africana, Grewia flava, Seddera suffruticosa, Melinis repens subsp. grandiflora, Combretum imberbe, Eragrostis trichophora, Aristida rhiniochloa, Urochloa brachyura, Melhania virescens, Euclea undulata, Enneapogon scoparius
The Combreto hereroense-Tarchonanthoetum camphorati forms an extensive low bushland to tall shrubland south of Grootfontein towards the Omuramba Omatako (Figures
This association occurs on shallow to moderately deep, medium-textured soils (often Leptsols) over calcrete, as part of lower Kalahari deposits (
Typical structure of the associations of the Thornbush – Karstveld transition: (a) Combreto hereroense-Tarchonanthoetum camphorati; (b) Aristido pilgeri-Vachellietum eriolobae; (c) Cenchro ciliaris-Senegalietum detinentis typicum; (d) Cenchro ciliaris-Senegalietum detinentis stipagrostietosum hirtiglumae; (e) Eucleo undulatae-Oleetum africanae.
Typical views of the associations of the Thornbush – Karstveld transition: (a) Combreto hereroense-Tarchonanthoetum camphorati, relevé 7987; (b) Aristido pilgeri-Vachellietum eriolobae, relevé 7804; (c) Cenchro ciliaris-Senegalietum detinentis typicum, relevé 3534; (d) Cenchro ciliaris-Senegalietum detinentis stipagrostietosum hirtiglumae, relevé 3521; (e) The Cenchro ciliaris-Senegalietum detinentis can degrade to this badly encroached state, relevé 7823; (f) Eucleo undulatae-Oleetum africanae, relevé 8001.
3.1.1.2 Aristido pilgeri-Vachellietum eriolobae ass. nov.
Number of relevés: 55
Number of species observed: 155
Estimated number of species: 292
Average species density in 1000 m2: 32
Type relevé: 7803 (holotypus), sampled on 26 April 2007 at 19.93222°S, 17.96028°E (Omambonde Tal)
Vachellia erioloba (t2) 10%, Vachellia luederitzii (t3) 2%, Philenoptera nelsii (t3) 1%, Senegalia mellifera subsp. mellifera (s1) 20%, Dichrostachys cinerea (s1) 5%, Grewia flava (s1) 5%, Senegalia cinerea (s1) 5%, Grewia bicolor (s1) 2%, Grewia flavescens (s1) 2%, Combretum hereroense (s1) 1%, Ehretia rigida (s1) 0.4%, Tarchonanthus camphoratus (s1) 0.4%, Pechuel-Loeschea leubnitziae (s2) 1%, Asparagus nelsii (s2) 0.4%, Commiphora angolensis (s2) 0.4%, Lantana angolensis (s2) 0.4%, Stipagrostis uniplumis var. uniplumis (gp) 40%, Aristida pilgeri (gp) 5%, Eragrostis rigidior (gp) 5%, Pogonarthria squarrosa (gp) 0.4%, Melinis repens subsp. grandiflora (ga) 1%, Urochloa brachyura (ga) 0.4%, Hermannia eenii (hl) 5%, Aptosimum angustifolium (hl) 1%, Hibiscus caesius (hl) 0.4%, Kyphocarpa angustifolia (hl) 0.4%, Melhania acuminata (hl) 0.4%, Nidorella resedifolia (hl) 0.4%, Otoptera burchellii (hl) 0.4%, Phyllanthus pentandrus (hl) 0.4%, Polydora steetziana (hl) 0.4%, Rhynchosia totta (hl) 0.4%, Seddera suffruticosa (hl) 0.4%, Waltheria indica (hl) 0.4%
Diagnostic species: Hermannia eenii, Aristida pilgeri, Melhania acuminata, Vachellia erioloba, Terminalia sericea, Senegalia cinerea, Dicoma schinzii, Waltheria indica, Digitaria seriata
Constant species: Senegalia mellifera subsp. detinens, Dichrostachys cinerea, Stipagrostis uniplumis var. uniplumis, Vachellia reficiens / luederitzii, Grewia flava
The Aristido pilgeri-Vachellietum eriolobae is mainly found near riverine systems through sandy substrate. Typical is the floodplain valley of the Omambonde Omatako along the southern edge of the study area, but also the Ugab headwaters south-west of Otavi and to the north and east of the Omuramba Ovambo between Maroelaboom and Oshivelo. The structure is typically a moderately closed tall bushland dominated by Senegalia mellifera subsp. detinens, Terminalia sericea, Peltophorum africanum, Vachellia erioloba, Senegalia cinerea, Dichrostachys cinerea, Vachellia reficiens / luederitzii and Philenoptera nelsii. In the grass layer, Stipagrostis uniplumis var. uniplumis, Eragrostis trichophora, Eragrostis rigidior, Eragrostis rotifer, Eragrostis lehmanniana, Aristida congesta subsp. congesta, Schmidtia pappophoroides and Pogonarthria fleckii dominate (Figures
3.1.1.3 Cenchro ciliaris-Senegalietum detinentis ass. nov.
Number of relevés: 216
Number of species observed: 323
Estimated number of species: 490
Average species density in 1000 m2: 44
Type relevé: 3330 (holotypus), sampled on 14 March 2002 at 19.85778°S, 17.42083°E (Okoruso)
Senegalia mellifera subsp. detinens (s1) 5%, Vachellia reficiens (s1) 5%, Ziziphus mucronata (s1) 0.5%, Lycium bosciifolium (s1) 0.2%, Grewia flava (s1) 0.1%, Pechuel-Loeschea leubnitziae (s2) 0.5%, Hibiscus calyphyllus (s2) 0.2%, Ziziphus mucronata (s2) 0.2%, Aizoon virgatum (s2) 0.1%, Asparagus cooperi (s2) 0.1%, Ehretia rigida (s2) 0.1%, Heliotropium nelsonii (s2) 0.1%, Leucosphaera bainesii (s2) 0.1%, Ptycholobium biflorum (s2) 0.1%, Solanum lichtensteinii (s2) 0.1%, Tarchonanthus camphoratus (s2) 0.1%, Eragrostis trichophora (gp) 25%, Cenchrus ciliaris (gp) 20%, Eragrostis echinochloidea (gp) 1%, Eragrostis rotifer (gp) 0.1%, Urochloa oligotricha (ga) 5%, Aristida adscensionis (ga) 0.1%, Aristida effusa (ga) 0.1%, Eragrostis porosa (ga) 0.1%, Melinis repens subsp. grandiflora (ga) 0.1%, Tragus berteronianus (ga) 0.1%, Nidorella resedifolia (hl) 0.5%, Cucumis anguria (hl) 0.2%, Ocimum filamentosum (hl) 0.2%, Commicarpus pentandrus (hl) 0.1%, Corchorus tridens (hl) 0.1%, Gomphrena celosioides (hl) 0.1%, Hibiscus palmatus (hl) 0.1%, Indigastrum costatum (hl) 0.1%, Ipomoea obscura var. obscura (hl) 0.1%, Ipomoea sinensis (hl) 0.1%, Ocimum americanum var. americanum (hl) 0.1%, Osteospermum muricatum subsp. muricatum (hl) 0.1%, Phyllanthus maderaspatensis (hl) 0.1%, Rhynchosia minima (hl) 0.1%, Ruellia species (hl) 0.1%, Senna italica (hl) 0.1%, Tribulus terrestris (hl) 0.1%
Diagnostic species: Corchorus tridens
Constant species: Senegalia mellifera subsp. detinens, Dichrostachys cinerea, Vachellia reficiens / luederitzii, Grewia flava, Melhania virescens, Cenchrus ciliaris, Eragrostis trichophora, Eragrostis echinochloidea
The Cenchro ciliaris-Senegalietum detinentis forms the relatively dense bushlands south of the Otavi Mountain range, roughly covering the triangle Rietfontein – Otavi – Otjiwarongo. The association occurs on the flat to undulating landscapes formed by the marbles and schists of the Swakop Group (
3.1.1.3.1 Cenchro ciliaris-Senegalietum detinentis typicum subass. nov.
Number of relevés: 71
Number of species observed: 216
Estimated number of species: 324
Average species density in 1000 m2: 46
Diagnostic species: Corchorus tridens, Heliotropium nelsonii, Leucosphaera bainesii, Monechma genistifolium, Ipomoea obscura var. obscura, Asparagus cooperi, Eragrostis porosa, Solanum tettense var. renschii, Hibiscus calyphyllus, Geigeria acaulis, Boscia albitrunca, Hibiscus palmatus, Ptycholobium biflorum subsp. angolensis
Constant species: Vachellia reficiens / luederitzii, Senegalia mellifera subsp. detinens, Eragrostis trichophora, Dichrostachys cinerea, Cenchrus ciliaris, Grewia flava
The Cenchro ciliaris-Senegalietum detinentis typicum occurs on deeper sandy loams and sandy clay loams, mostly Chromic Cambisols. There has only limited stone cover recorded on single relevés. The subassociation occurs on flat to gently undulating slopes at an altitudinal range of between 1170 and 1550 m a.s.l.
3.1.1.3.2 Cenchro ciliaris-Senegalietum detinentis stipagrostietosum hirtiglumae subass. nov.
Number of relevés: 145
Number of species observed: 254
Estimated number of species: 431
Average species density in 1000 m2: 43
Type relevé: 3521 (holotypus), sampled on 25 April 2002 at 20.05667°S, 17.04750°E (Gerhardtshausen / Felsenquelle)
Peltophorum africanum (t3) 5%, Senegalia mellifera subsp. detinens (s1) 40%, Croton gratissimus var. gratissimus (s1) 10%, Dichrostachys cinerea (s1) 5%, Vachellia reficiens (s1) 5%, Grewia flava (s1) 2%, Tarchonanthus camphoratus (s1) 2%, Terminalia prunioides (s1) 2%, Catophractes alexandri (s1) 1%, Combretum hereroense (s1) 0.5%, Euclea undulata (s1) 0.5%, Searsia marlothii (s1) 0.2%, Ehretia rigida (s2) 0.5%, Hypoestes forskaolii (s2) 0.5%, Melhania virescens (s2) 0.5%, Aizoon virgatum (s2) 0.2%, Lantana angolensis (s2) 0.2%, Mundulea sericea (s2) 0.2%, Seddera suffruticosa (s2) 0.2%, Boscia foetida subsp. foetida (s2) 0.1%, Chascanum pinnatifidum (s2) 0.1%, Commiphora pyracanthoides (s2) 0.1%, Helichrysum tomentosulum (s2) 0.1%, Hibiscus caesius (s2) 0.1%, Enneapogon scoparius (gp) 5%, Eragrostis echinochloidea (gp) 5%, Heteropogon contortus (gp) 2%, Cenchrus ciliaris (gp) 0.5%, Fingerhuthia africana (gp) 0.5%, Dichanthium annulatum var. papillosum (gp) 0.2%, Stipagrostis hirtigluma (ga) 15%, Indigofera charlieriana (hl) 0.1%, Ocimum americanum var. americanum (hl) 0.1%, Sericorema sericea (hl) 0.1%
Constant species: Senegalia mellifera subsp. detinens, Combretum hereroense, Grewia flava, Dichrostachys cinerea, Melhania virescens, Vachellia reficiens / luederitzii, Eragrostis echinochloidea, Tarchonanthus camphoratus
The soils consist of sandy loam and sandy clay loam, often mollic Leptosols or petric Calcisols (
3.1.1.4 Eucleo undulatae - Oleetum africanae ass. nov.
Number of relevés: 32
Number of species observed: 189
Estimated number of species: 318
Type relevé: 8097 (holotypus), sampled on 15 April 2008 at 19.44583°S, 17.95917°E (Toggenberg)
Spirostachys africana (t1) 10%, Elaeodendron transvaalense (t2) 1%, Vachellia luederitzii (t3) 5%, Commiphora glandulosa (t3) 1%, Senegalia mellifera subsp. detinens (s1) 20%, Croton gratissimus var. subgratissimus (s1) 10%, Olea europaea subsp. africana (s1) 10%, Euclea undulata (s1) 5%, Searsia marlothii (s1) 2%, Terminalia prunioides (s1) 2%, Commiphora africana (s1) 1%, Commiphora glandulosa (s1) 1%, Dombeya rotundifolia (s1) 1%, Flueggea virosa (s1) 1%, Mundulea sericea (s1) 1%, Vachellia nilotica (s1) 1%, Lantana angolensis (s2) 1%, Aerva leucura (s2) 0.5%, Fingerhuthia africana (gp) 5%, Enneapogon scoparius (gp) 2%, Eragrostis echinochloidea (gp) 2%, Eragrostis rigidior (gp) 2%, Heteropogon contortus (gp) 2%, Andropogon chinensis (gp) 1%, Anthephora pubescens (gp) 1%, Cenchrus ciliaris (gp) 1%, Eragrostis nindensis (gp) 1%, Oropetium capense (gp) 1%, Urochloa oligotricha (gp) 1%, Cymbopogon pospischilii (gp) 0.5%, Digitaria eriantha (gp) 0.5%, Eustachys paspaloides (gp) 0.5%, Enneapogon cenchroides (ga) 10%, Eragrostis porosa (ga) 10%, Aristida effusa (ga) 5%, Aristida rhiniochloa (ga) 2%, Enneapogon desvauxii (ga) 2%, Melinis repens subsp. grandiflora (ga) 2%, Brachiaria malacodes (ga) 1%, Tragus racemosus (ga) 0.5%, Cyperus amabilis (hl) 2%, Blepharis obmitrata (hl) 1%, Buchnera hispida (hl) 1%, Calostephane divaricata (hl) 1%, Achyranthes aspera var. sicula (hl) 0.5%, Aptosimum lineare (hl) 0.5%, Commelina benghalensis (hl) 0.5%, Geigeria ornativa (hl) 0.5%, Heliotropium ovalifolium (hl) 0.5%, Hibiscus calyphyllus (hl) 0.5%, Indigofera charlieriana (hl) 0.5%, Kohautia aspera (hl) 0.5%, Melhania virescens (hl) 0.5%, Monechma spartioides (hl) 0.5%, Pavonia burchellii (hl) 0.5%, Pentarrhinum insipidum (hl) 0.5%, Pupalia lappacea (hl) 0.5%, Sericorema sericea (hl) 0.5%, Tagetes minuta (hl) 0.5%, Tephrosia dregeana var. dregeana (hl) 0.5%
Diagnostic species: Olea europaea subsp. africana, Fingerhuthia africana, Digitaria eriantha, Euclea undulata, Croton gratissimus, Kohautia aspera
Constant species: Senegalia mellifera subsp. detinens, Heteropogon contortus, Vachellia reficiens / luederitzii, Melhania virescens, Searsia marlothii, Combretum hereroense, Eragrostis echinochloidea, Ziziphus mucronata, Enneapogon scoparius, Lantana angolensis, Cenchrus ciliaris, Tarchonanthus camphoratus, Seddera suffruticosa, Hibiscus caesius, Grewia flava, Dichrostachys cinerea, Anthephora pubescens
The Eucleo undulatae-Oleetum africanae forms a short, moderately closed thicket dominated by the phanerophytes Senegalia mellifera subsp. detinens, Olea europaea subsp. africana, Vachellia reficiens / luederitzii, Dichrostachys cinerea, Combretum imberbe, Combretum hereroense, Euclea undulata and Catophractes alexandri. The grass sward consists of predominantly Enneapogon desvauxii, Heteropogon contortus, Urochloa oligotricha, Stipagrostis uniplumis var. uniplumis, Fingerhuthia africana, Enneapogon scoparius, Cenchrus ciliaris, Eragrostis trichophora and Eragrostis echinochloidea (Figures
This association occurs on the southern footslopes and pedeplains of the Otavi mountain range. It is especially widespread around Otavi but is found also elsewhere along the mountain range as far east as Gaikos mountain. The soils are described as medium-textured, dark Leptosols on calcretes (
Pockets of Kalahari sand deposits are found within the Otavi Mountain range, supporting vegetation typical for the Woodland savanna of the northern Kalahari sensu
Abbreviated synoptic table for the Kalahari vegetation, showing all species occurring in more than 10% of relevés of this group, with fidelity (phi coefficient × 100) and frequency of occurrence (%).
Association | 4.1.1.1 | 4.1.1.2 | 4.1.1.3 | 4.1.1.4 | ||||
---|---|---|---|---|---|---|---|---|
No of relevés | 11 | 25 | 15 | 21 | ||||
Species | phi | % | phi | % | phi | % | phi | % |
Grewia olukondae | 69 | 100 | --- | 28 | --- | 0 | --- | 38 |
Tricholaena monachne | 65 | 55 | --- | 4 | --- | 0 | --- | 0 |
Monechma debile | 62 | 45 | --- | 0 | --- | 0 | --- | 0 |
Schinziophyton rautanenii | 56 | 45 | --- | 0 | --- | 7 | --- | 0 |
Pterocarpus angolensis | 55 | 36 | --- | 0 | --- | 0 | --- | 0 |
Indigofera daleoides | 51 | 64 | --- | 12 | --- | 20 | --- | 5 |
Phyllanthus maderaspatensis | 51 | 64 | --- | 24 | --- | 0 | --- | 14 |
Aristida stipitata | 48 | 91 | --- | 52 | --- | 20 | --- | 33 |
Hibiscus vitifolius | 47 | 27 | --- | 0 | --- | 0 | --- | 0 |
Strychnos pungens | 47 | 27 | --- | 0 | --- | 0 | --- | 0 |
Chamaecrista biensis | 42 | 36 | --- | 8 | --- | 0 | --- | 5 |
Burkea africana | 42 | 45 | --- | 12 | --- | 13 | --- | 0 |
Ochna pulchra | 41 | 64 | --- | 32 | --- | 27 | --- | 0 |
Jacquemontia tamnifolia | --- | 9 | 76 | 80 | --- | 7 | --- | 0 |
Calostephane divaricata | --- | 0 | 61 | 44 | --- | 0 | --- | 0 |
Ozoroa schinzii | --- | 9 | 59 | 52 | --- | 0 | --- | 0 |
Combretum engleri | --- | 9 | 56 | 48 | --- | 0 | --- | 0 |
Phyllanthus omahakensis | --- | 0 | 55 | 36 | --- | 0 | --- | 0 |
Acanthosicyos naudinianus | --- | 0 | 54 | 56 | --- | 7 | --- | 14 |
Schmidtia kalahariensis | --- | 0 | 48 | 28 | --- | 0 | --- | 0 |
Megaloprotachne albescens | --- | 0 | 44 | 24 | --- | 0 | --- | 0 |
Polydora steetziana | --- | 0 | 42 | 44 | --- | 0 | --- | 24 |
Bauhinia petersiana subsp. macrantha | --- | 64 | 40 | 84 | --- | 40 | --- | 10 |
Grewia flavescens | --- | 0 | --- | 56 | 62 | 100 | --- | 29 |
Pavonia burchellii | --- | 0 | --- | 4 | 59 | 47 | --- | 0 |
Limeum sulcatum | --- | 0 | --- | 0 | 56 | 53 | --- | 14 |
Senegalia ataxacantha | --- | 36 | --- | 60 | 53 | 93 | --- | 0 |
Commelina benghalensis | --- | 0 | --- | 4 | 51 | 47 | --- | 10 |
Ziziphus mucronata | --- | 0 | --- | 4 | 50 | 53 | --- | 19 |
Ipomoea welwitschii | --- | 0 | --- | 0 | 47 | 33 | --- | 5 |
Chamaecrista absus | --- | 0 | 25 | 52 | 43 | 67 | --- | 10 |
Tarchonanthus camphoratus | --- | 0 | --- | 0 | 40 | 27 | --- | 5 |
Terminalia prunioides | --- | 0 | --- | 32 | --- | 13 | 65 | 86 |
Combretum hereroense | --- | 0 | --- | 0 | --- | 7 | 53 | 43 |
Seddera suffruticosa | --- | 0 | --- | 0 | --- | 0 | 48 | 29 |
Senegalia mellifera subsp. detinens | --- | 18 | --- | 16 | --- | 67 | 45 | 86 |
Aristida rhiniochloa | --- | 0 | --- | 12 | --- | 7 | 44 | 43 |
Hyphaene petersiana | --- | 9 | --- | 0 | --- | 0 | 43 | 33 |
Boscia albitrunca | --- | 0 | --- | 4 | --- | 7 | 41 | 33 |
Combretum collinum | 45 | 82 | 57 | 92 | --- | 0 | --- | 0 |
Terminalia sericea | --- | 91 | --- | 96 | --- | 93 | --- | 67 |
Dichrostachys cinerea | --- | 55 | --- | 80 | --- | 87 | 29 | 100 |
Urochloa brachyura | --- | 55 | --- | 84 | --- | 87 | --- | 95 |
Stipagrostis uniplumis var. uniplumis | --- | 82 | --- | 80 | --- | 60 | --- | 86 |
Croton gratissimus | 38 | 100 | 27 | 92 | --- | 47 | --- | 43 |
Combretum apiculatum | --- | 45 | --- | 60 | --- | 60 | 32 | 90 |
Senegalia cinerea | --- | 45 | --- | 68 | --- | 87 | --- | 62 |
Melinis repens subsp. grandiflora | --- | 64 | 30 | 88 | --- | 47 | --- | 52 |
Grewia bicolor | --- | 27 | --- | 64 | --- | 60 | 27 | 81 |
Pogonarthria fleckii | --- | 18 | 37 | 84 | --- | 27 | 33 | 81 |
Commiphora glandulosa | --- | 36 | --- | 64 | --- | 53 | --- | 67 |
Peltophorum africanum | --- | 36 | --- | 16 | 32 | 80 | 28 | 76 |
Eragrostis dinteri | --- | 55 | 33 | 68 | --- | 0 | --- | 38 |
Commiphora angolensis | --- | 9 | 40 | 64 | --- | 40 | --- | 14 |
Vachellia erioloba | --- | 18 | 25 | 52 | --- | 20 | --- | 38 |
Oxygonum alatum | --- | 18 | 26 | 52 | --- | 27 | --- | 29 |
Melhania acuminata | --- | 18 | --- | 20 | 32 | 60 | --- | 38 |
Grewia flava | --- | 0 | --- | 40 | --- | 33 | --- | 33 |
Limeum fenestratum | --- | 45 | --- | 40 | --- | 7 | --- | 24 |
Schmidtia pappophoroides | --- | 18 | --- | 28 | --- | 20 | --- | 43 |
Tephrosia dregeana var. dregeana | --- | 18 | --- | 28 | --- | 47 | --- | 24 |
Clerodendrum ternatum | --- | 18 | --- | 24 | --- | 47 | --- | 24 |
Philenoptera nelsii | --- | 0 | --- | 40 | --- | 33 | --- | 24 |
Eragrostis rigidior | --- | 0 | --- | 12 | --- | 40 | 35 | 52 |
Aristida adscensionis | --- | 36 | 31 | 48 | --- | 0 | --- | 14 |
Bidens biternata | --- | 36 | --- | 20 | 30 | 53 | --- | 10 |
Combretum psidioides | 33 | 55 | --- | 32 | --- | 13 | --- | 14 |
Evolvulus alsinoides | --- | 9 | --- | 28 | --- | 13 | 27 | 43 |
Digitaria seriata | --- | 18 | --- | 36 | --- | 13 | --- | 29 |
Ximenia americana | 35 | 55 | --- | 20 | --- | 7 | --- | 29 |
Rhynchosia venulosa | 40 | 64 | --- | 8 | --- | 40 | --- | 14 |
Syncolostemon bracteosus | --- | 9 | 29 | 44 | --- | 33 | --- | 5 |
Vachellia reficiens / luederitzii | --- | 0 | --- | 24 | --- | 13 | 37 | 48 |
Sida ovata | --- | 27 | --- | 32 | --- | 13 | --- | 19 |
Eragrostis trichophora | --- | 36 | --- | 16 | --- | 7 | --- | 33 |
Searsia tenuinervis | --- | 36 | --- | 20 | --- | 13 | --- | 24 |
Waltheria indica | --- | 9 | --- | 12 | --- | 33 | --- | 33 |
Asparagus nelsii | --- | 0 | --- | 32 | --- | 27 | --- | 19 |
Mundulea sericea | --- | 27 | --- | 24 | --- | 20 | --- | 14 |
Bulbostylis hispidula | --- | 0 | 29 | 36 | --- | 13 | --- | 19 |
Xenostegia tridentata subsp. angustifolia | --- | 0 | 37 | 40 | --- | 7 | --- | 19 |
Tragus berteronianus | --- | 9 | --- | 28 | --- | 7 | --- | 24 |
Cyperus margaritaceus | --- | 27 | --- | 8 | 24 | 40 | --- | 14 |
Enneapogon cenchroides | --- | 0 | 34 | 36 | --- | 0 | --- | 24 |
Lantana angolensis | --- | 0 | --- | 16 | --- | 27 | --- | 29 |
Panicum maximum | --- | 36 | --- | 28 | --- | 7 | --- | 5 |
Commelina africana | --- | 36 | --- | 12 | --- | 27 | --- | 10 |
Albizia anthelmintica | --- | 0 | --- | 24 | --- | 20 | --- | 19 |
Commiphora africana | --- | 0 | 29 | 32 | --- | 7 | --- | 19 |
Tephrosia purpurea | --- | 0 | 30 | 32 | --- | 0 | --- | 24 |
Eragrostis lehmanniana | --- | 0 | --- | 28 | 35 | 40 | --- | 0 |
Dicoma tomentosa | --- | 0 | --- | 8 | --- | 20 | 34 | 38 |
Kyphocarpa angustifolia | --- | 9 | --- | 20 | --- | 7 | --- | 24 |
Melinis repens subsp. repens | --- | 27 | --- | 0 | --- | 33 | --- | 19 |
Triraphis schinzii | --- | 18 | --- | 4 | --- | 20 | --- | 29 |
Aristida congesta subsp. congesta | --- | 9 | --- | 12 | --- | 0 | 38 | 38 |
Phyllanthus pentandrus | --- | 0 | --- | 8 | 36 | 40 | --- | 19 |
Cyperus amabilis | --- | 0 | --- | 28 | --- | 13 | --- | 14 |
Cleome rubella | --- | 0 | --- | 12 | --- | 33 | --- | 19 |
Heteropogon melanocarpus | --- | 0 | 34 | 32 | --- | 13 | --- | 5 |
Acrotome angustifolia | --- | 0 | 37 | 32 | --- | 0 | --- | 14 |
Gisekia africana | --- | 0 | --- | 12 | --- | 27 | --- | 19 |
Rhynchosia totta | --- | 0 | --- | 24 | --- | 7 | --- | 19 |
Sporobolus panicoides | --- | 0 | --- | 12 | --- | 20 | --- | 24 |
Vachellia nilotica | --- | 0 | --- | 12 | --- | 13 | --- | 29 |
Zornia milneana | --- | 0 | --- | 12 | 30 | 33 | --- | 14 |
Aristida pilgeri | --- | 0 | --- | 0 | --- | 20 | 39 | 38 |
Blepharis obmitrata | --- | 27 | --- | 12 | --- | 0 | --- | 19 |
Thunbergia aurea | --- | 27 | --- | 8 | 25 | 33 | --- | 0 |
Blepharis maderaspatensis | --- | 27 | --- | 4 | --- | 27 | --- | 10 |
Tephrosia lupinifolia | --- | 9 | 36 | 32 | --- | 7 | --- | 0 |
Spermacoce senensis | --- | 0 | --- | 16 | 33 | 33 | --- | 5 |
Dicoma schinzii | --- | 9 | --- | 20 | --- | 7 | --- | 10 |
Sesamum triphyllum | --- | 9 | 24 | 24 | --- | 7 | --- | 5 |
Ximenia caffra | --- | 9 | --- | 12 | 33 | 33 | --- | 0 |
Setaria pumila | --- | 9 | --- | 0 | 32 | 33 | --- | 14 |
Spirostachys africana | --- | 0 | --- | 8 | --- | 13 | --- | 24 |
Monechma spartioides | --- | 0 | --- | 4 | --- | 20 | --- | 24 |
Combretum imberbe | --- | 0 | --- | 0 | --- | 20 | 29 | 29 |
Erlangea misera | 40 | 36 | --- | 16 | --- | 0 | --- | 0 |
Indigofera flavicans | 38 | 36 | --- | 12 | --- | 7 | --- | 0 |
Asparagus exuvialis | --- | 0 | --- | 16 | --- | 0 | --- | 19 |
Gymnosporia senegalensis | --- | 0 | --- | 0 | --- | 13 | 34 | 29 |
Overview of the Kalahari associations:
4.1 Undefined upper hierarchy
4.1.1.1 Terminalio sericeae-Schinziophyetum rautanenii
4.1.1.2 Combreto collini-Terminalietum sericeae
4.1.1.3 Senegalio cinereae-Peltophoretum africanae
4.1.1.4 Terminalietum sericeo-prunioidis
4.1.1.1 Terminalio sericeae - Schinziophyetum rautanenii B. Strohbach 2014
Number of relevés: 11
Number of species observed: 72
Estimated number of species: 106
Average species density in 1000 m2: 30
Type relevé: 4013 (holotypus), designated by Strohbach (
Schinziophyton rautanenii (t1) 2a, Pterocarpus angolensis (t1) +, Burkea africana (t2) 1, Combretum collinum (t2) +, Lannea discolor (t2) r, Peltophorum africanum (t3) +, Croton gratissimus var. gratissimus (s1) 2b, Terminalia sericea (s1) 2b, Bauhinia petersiana subsp. macrantha (s1) +, Grewia olukondae (s1) +, Ochna pulchra (s2) +, Strychnos pungens (s2) r, Eragrostis trichophora (gp) 1, Melinis repens subsp. repens (gp) +, Panicum maximum (gp) +, Stipagrostis uniplumis var. uniplumis (gp) +, Aristida stipitata subsp. stipitata (ga) 3, Melinis repens subsp. grandiflora (ga) +, Tricholaena monachne (ga) +, Erlangea misera (hl) 1, Bidens biternata (hl) +, Blepharis obmitrata (hl) +, Cyperus margaritaceus (hl) +, Hibiscus vitifolius (hl) +, Hypoestes forskaolii (hl) +, Indigofera daleoides (hl) +, Indigofera flavicans (hl) +, Monechma debile (hl) +, Phyllanthus maderaspatensis (hl) +, Rhynchosia sublobata (hl) +, Sida ovata (hl) +, Tephrosia dregeana var. dregeana (hl) +, Thunbergia aurea (hl) +
Diagnostic species: Grewia olukondae, Tricholaena monachne, Monechma debile, Schinziophyton rautanenii, Pterocarpus angolensis, Indigofera daleoides, Phyllanthus maderaspatensis, Aristida stipitata, Strychnos pungens, Hibiscus vitifolius, Combretum collinum, Chamaecrista biensis, Burkea africana, Ochna pulchra
Constant species: Croton gratissimus, Terminalia sericea, Stipagrostis uniplumis var. uniplumis, Rhynchosia venulosa, Melinis repens subsp. grandiflora, Bauhinia petersiana subsp. macrantha
The Terminalio sericeae-Schinziophyetum rautanenii forms a tall, moderately closed woodland dominated by Terminalia sericea, Combretum apiculatum, Senegalia cinerea, Pterocarpus angolensis, Croton gratissimus, Combretum collinum and Schinziophyton rautanenii. The grass sward is not well developed, featuring Aristida stipitata, Stipagrostis uniplumis var. uniplumis and Melinis repens subsp. grandiflora. Other than the conspicuous presence of the tall tree species Pterocarpus angolensis and Schinziophyton rautanenii, the composition resembles that of the Combreto collini-Terminalietum sericeae (Figure
The Terminalio sericeae-Schinziophyetum rautanenii has especially been found on east-facing sand ramps of aeolian origin (
4.1.1.2 Combreto collini - Terminalietum sericeae B. Strohbach 2014
Number of relevés: 25
Number of species observed: 127
Estimated number of species: 213
Average species density in 1000 m2: 41
Diagnostic species: Jacquemontia tamnifolia, Calostephane divaricata, Ozoroa schinzii, Combretum collinum, Combretum engleri, Phyllanthus omahakensis, Acanthosicyos naudinianus, Schmidtia kalahariensis, Megaloprotachne albescens, Polydora steetziana, Bauhinia petersiana subsp. macrantha
Constant species: Terminalia sericea, Croton gratissimus, Melinis repens subsp. grandiflora, Urochloa brachyura, Pogonarthria fleckii, Stipagrostis uniplumis var. uniplumis, Dichrostachys cinerea, Senegalia cinerea, Eragrostis dinteri, Grewia bicolor, Commiphora glandulosa, Commiphora angolensis
The Combreto collini-Terminalietum sericeae forms a short, moderately closed bushland dominated by the phanerophytes Terminalia sericea, Croton gratissimus, Bauhinia petersiana subsp. macrantha, Combretum psidioides, Combretum collinum and Grewia olukondae. The grass sward is dominated by Aristida stipitata, Schmidtia kalahariensis, Megaloprotachne albescens, Eragrostis trichophora, Pogonarthria fleckii, Melinis repens subsp. grandiflora, Eragrostis rigidior and Eragrostis dinteri, with Polydora steetziana a conspicuous annual herb in the matrix (Figures
The Combreto collini-Terminalietum sericeae occurs on the Kalahari dune belt east and north of the Omuramba Ovambo. The presence of Combretum apiculatum, Vachellia tortilis subsp. heteracantha and Terminalia prunioides indicates the proximity to true Karstveld vegetation. This could possibly result in the recognition of a further subassociation of this very wide-spread association (cf.
4.1.1.3 Senegalio cinereae - Peltophoretum africanae ass. nov.
Number of relevés: 15
Number of species observed: 141
Estimated number of species: 244
Average species density in 1000 m2: 40
Type relevé: 8000 (holotypus), sampled on 12 March 2008 at 19.55588°S, 17.14389°E (Gobas Pforte)
Combretum imberbe (t3) 5%, Commiphora tenuipetiolata (t3) 1%, Terminalia sericea (t2) 20%, Combretum apiculatum subsp. apiculatum (t2) 5%, Spirostachys africana (t2) 2%, Pavetta zeyheri (s2) 0.5%, Dichrostachys cinerea (s1) 10%, Grewia flavescens (s1) 10%, Senegalia ataxacantha (s1) 10%, Senegalia cinerea (s1) 10%, Grewia bicolor (s1) 5%, Peltophorum africanum (s1) 5%, Rhigozum brevispinosum (s1) 2%, Ziziphus mucronata (s1) 2%, Senegalia mellifera subsp. detinens (s1) 1%, Commiphora angolensis (s1) 0.5%, Croton gratissimus var. subgratissimus (s1) 0.5%, Eragrostis lehmanniana var. lehmanniana (gp) 1%, Eragrostis porosa (ga) 10%, Setaria pumila (ga) 10%, Urochloa brachyura (ga) 10%, Tragus racemosus (ga) 2%, Brachiaria deflexa (ga) 1%, Aristida stipoides (ga) 0.5%, Melinis repens subsp. grandiflora (ga) 0.5%, Spermacoce senensis (hl) 5%, Achyranthes aspera var. sicula (hl) 2%, Bidens biternata (hl) 2%, Chamaecrista absus (hl) 1%, Ipomoea sinensis (hl) 1%, Cleome rubella (hl) 0.5%, Crassocephalum coeruleum (hl) 0.5%, Cyperus amabilis (hl) 0.5%, Erucastrum arabicum (hl) 0.5%, Euphorbia inaequilatera (hl) 0.5%, Gisekia africana (hl) 0.5%, Limeum sulcatum (hl) 0.5%, Melhania acuminata (hl) 0.5%, Pavonia burchellii (hl) 0.5%, Phyllanthus pentandrus (hl) 0.5%, Sesamum triphyllum (hl) 0.5%, Solanum lichtensteinii (hl) 0.5%, Zornia milneana (hl) 0.5%
Diagnostic species: Grewia flavescens, Pavonia burchellii, Limeum sulcatum, Senegalia ataxacantha, Commelina benghalensis, Ziziphus mucronata, Ipomoea welwitschii, Chamaecrista absus, Tarchonanthus camphoratus
Constant species: Terminalia sericea, Urochloa brachyura, Senegalia cinerea, Dichrostachys cinerea, Peltophorum africanum, Senegalia mellifera subsp. detinens
The Senegalio cinereae-Peltophoretum africanae forms a tall, moderately closed to closed thicket, dominated by the phanerophytes Terminalia sericea, Senegalia cinerea, Senegalia ataxacantha, Peltophorum africanum, Dichrostachys cinerea, Croton gratissimus and Combretum apiculatum. These are accompanied by the grasses Urochloa brachyura, Setaria pumila and Eragrostis rigidior (Figures
4.1.1.4 Terminalietum sericeo - prunioidis ass. nov.
Number of relevés: 21
Number of species observed: 157
Estimated number of species: 273
Average species density in 1000 m2: 38
Type relevé: 8131 (holotypus), sampled on 18 April 2008 at 18.80028°S, 17.88139°E (Rushof)
Terminalia prunioides (t2) 10%, Hyphaene petersiana (t2) 5%, Vachellia erioloba (t2) 2%, Spirostachys africana (t2) 1%, Combretum apiculatum subsp. apiculatum (t3) 10%, Combretum imberbe (t3) 2%, Commiphora glandulosa (t3) 2%, Terminalia sericea (t3) 1%, Vachellia luederitzii (t3) 1%, Senegalia mellifera subsp. detinens (s2) 1%, Grewia bicolor (s1) 10%, Combretum hereroense (s1) 5%, Grewia flavescens (s1) 5%, Ximenia americana (s1) 2%, Croton gratissimus var. subgratissimus (s1) 1%, Dichrostachys cinerea (s1) 1%, Elaeodendron transvaalense (s1) 1%, Hyphaene petersiana (s1) 1%, Peltophorum africanum (s1) 1%, Ziziphus mucronata (s2) 0.5%, Eragrostis rigidior (gp) 2%, Stipagrostis uniplumis var. uniplumis (gp) 2%, Triraphis schinzii (gp) 1%, Brachiaria nigropedata (gp) 0.5%, Fingerhuthia africana (gp) 0.5%, Heteropogon contortus (gp) 0.5%, Schizachyrium sanguineum (gp) 0.5%, Schmidtia pappophoroides (gp) 0.5%, Pogonarthria fleckii (ga) 10%, Aristida rhiniochloa (ga) 2%, Eragrostis dinteri (ga) 2%, Aristida effusa (ga) 0.5%, Enneapogon cenchroides (ga) 0.5%, Melinis repens subsp. grandiflora (ga) 0.5%, Urochloa brachyura (ga) 0.5%, Polydora steetziana (hl) 10%, Monechma spartioides (hl) 5%, Ocimum americanum var. americanum (hl) 5%, Cyperus amabilis (hl) 1%, Waltheria indica (hl) 1%, Acrotome angustifolia (hl) 0.5%, Aptosimum decumbens (hl) 0.5%, Blepharis obmitrata (hl) 0.5%, Dicoma tomentosa (hl) 0.5%, Evolvulus alsinoides (hl) 0.5%, Geigeria ornativa (hl) 0.5%, Gymnema sylvestre (hl) 0.5%, Heliotropium nelsonii (hl) 0.5%, Hermannia eenii (hl) 0.5%, Hibiscus caesius (hl) 0.5%, Kyllinga alata (hl) 0.5%, Kyphocarpa angustifolia (hl) 0.5%, Melhania acuminata (hl) 0.5%, Ocimum filamentosum (hl) 0.5%, Seddera suffruticosa (hl) 0.5%, Sida ovata (hl) 0.5%, Tephrosia purpurea (hl) 0.5%, Zornia milneana (hl) 0.5%.
Diagnostic species: Terminalia prunioides, Combretum hereroense, Seddera suffruticosa, Senegalia mellifera subsp. detinens, Aristida rhiniochloa, Hyphaene petersiana, Boscia albitrunca
Constant species: Dichrostachys cinerea, Urochloa brachyura, Combretum apiculatum, Stipagrostis uniplumis var. uniplumis, Pogonarthria fleckii, Grewia bicolor, Peltophorum africanum, Terminalia sericea, Commiphora glandulosa, Senegalia cinerea
The Terminalietum sericeo-prunioidis forms a short, moderately closed bushland. It is dominated by the phanerophytes Combretum apiculatum, Dichrostachys cinerea and Terminalia prunioides, with Stipagrostis uniplumis var. uniplumis, Eragrostis rigidior and Aristida pilgeri forming the grass sward (Figures
Synopsis:
Number of relevés: 330
Holotypus: Terminalietalia prunioidis B. Strohbach & M. Strohbach 2023 (see below)
Number of species observed: 640
Diagnostic species: Terminalia prunioides, Spirostachys africana, Combretum apiculatum, Vachellia nilotica, Grewia villosa, Grewia bicolor
Constant species: Dichrostachys cinerea, Senegalia mellifera subsp. detinens, Commiphora glandulosa, Melinis repens subsp. grandiflora, Urochloa brachyura, Croton gratissimus, Grewia flavescens, Combretum imberbe
The Karstveld sensu
Abbreviated synoptic table for the Terminalietea prunioidis, showing all species occurring in more than 10% of relevés of the class, with fidelity (phi coefficient × 100) and frequency of occurrence (%).
Order | 5.1 Commiphoro glaucescentis- Kirkietalia acuminatae | 5.2 Terminalietalia prunioidis | ||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Alliance | 5.1.1 Commiphoro glaucescentis- Kirkion acuminatae | 5.2.1 | 5.2.2 Terminalio prunioidis-Hyphaenion petersianae | 5.2.3 Dichrostachyo cinereae-Terminalion prunioidis | ||||||||||||
Association | 5.1.1.1 | 5.1.1.2 | 5.1.1.3 | 5.2.1.1 | 5.2.1.2 | 5.2.2.1 | 5.2.3.1 | 5.2.3.2 | ||||||||
No of relevés | 18 | 15 | 21 | 34 | 49 | 78 | 71 | 98 | ||||||||
Species | phi | % | phi | % | phi | % | phi | % | phi | % | phi | % | phi | % | phi | % |
Vangueria infausta | 75 | 61 | --- | 0 | --- | 0 | --- | 0 | --- | 2 | --- | 0 | --- | 0 | --- | 0 |
Pellaea calomelanos | 68 | 50 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Cheilanthes dinteri | 65 | 61 | --- | 7 | --- | 10 | --- | 0 | --- | 2 | --- | 0 | --- | 0 | --- | 0 |
Lannea discolor | 59 | 78 | 9 | 27 | 15 | 33 | --- | 0 | --- | 2 | --- | 1 | --- | 0 | --- | 1 |
Cleome monophylla | 55 | 39 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 1 | --- | 4 |
Macrotyloma axillare | 51 | 33 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 3 | --- | 2 |
Ozoroa insignis | 48 | 72 | --- | 7 | --- | 29 | --- | 9 | 7 | 29 | --- | 6 | --- | 10 | --- | 7 |
Andropogon gayanus var. polycladus | 46 | 28 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 1 | --- | 3 | --- | 0 |
Merremia pinnata | 43 | 22 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 1 | --- | 0 | --- | 0 |
Ipomoea verbascoidea | 43 | 39 | --- | 13 | --- | 5 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 8 |
Thunbergia aurea | 41 | 39 | 16 | 20 | --- | 0 | --- | 0 | --- | 0 | --- | 1 | --- | 6 | --- | 2 |
Danthoniopsis dinteri | 40 | 61 | 64 | 87 | --- | 5 | --- | 0 | --- | 2 | --- | 0 | --- | 0 | --- | 1 |
Cissus nymphaeifolia | 17 | 33 | 58 | 73 | 8 | 24 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Steganotaenia araliacea var. araliacea | 20 | 28 | 58 | 60 | --- | 0 | --- | 0 | --- | 0 | --- | 1 | --- | 0 | --- | 1 |
Ficus cordata | --- | 0 | 49 | 27 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Crassocephalum coeruleum | --- | 0 | 47 | 27 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 1 | --- | 1 |
Actiniopteris radiata | 8 | 17 | 45 | 47 | 11 | 19 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Berchemia discolor | --- | 0 | 44 | 47 | --- | 5 | --- | 9 | --- | 10 | --- | 3 | 2 | 13 | --- | 0 |
Triraphis ramosissima | --- | 0 | 42 | 27 | --- | 0 | --- | 0 | --- | 6 | --- | 0 | --- | 0 | --- | 1 |
Momordica humilis | --- | 0 | 41 | 20 | --- | 0 | --- | 0 | --- | 0 | --- | 1 | --- | 0 | --- | 0 |
Boscia albitrunca | --- | 11 | 40 | 47 | --- | 0 | --- | 0 | --- | 4 | --- | 6 | --- | 13 | --- | 15 |
Fingerhuthia africana | --- | 0 | --- | 0 | 64 | 71 | --- | 0 | --- | 10 | --- | 4 | --- | 0 | 11 | 23 |
Searsia marlothii | --- | 11 | 16 | 47 | 53 | 90 | --- | 12 | --- | 0 | --- | 19 | --- | 13 | 2 | 31 |
Dombeya rotundifolia | 35 | 72 | 13 | 47 | 50 | 90 | --- | 0 | --- | 8 | --- | 3 | --- | 0 | --- | 22 |
Anthephora pubescens | --- | 22 | --- | 20 | 49 | 71 | --- | 9 | --- | 12 | --- | 12 | --- | 4 | --- | 9 |
Eragrostis nindensis | --- | 44 | --- | 33 | 45 | 100 | 4 | 47 | 12 | 57 | --- | 15 | --- | 3 | --- | 34 |
Heteropogon contortus | 14 | 56 | --- | 20 | 45 | 95 | --- | 12 | --- | 39 | --- | 40 | --- | 13 | --- | 31 |
Ophioglossum polyphyllum | --- | 0 | --- | 0 | 43 | 29 | --- | 0 | --- | 2 | --- | 1 | --- | 0 | --- | 5 |
Anthephora schinzii | --- | 0 | --- | 0 | --- | 0 | 66 | 76 | 19 | 33 | --- | 0 | --- | 6 | --- | 2 |
Ipomoea adenioides | --- | 0 | --- | 0 | --- | 0 | 64 | 47 | --- | 0 | --- | 3 | --- | 0 | --- | 0 |
Tragus pedunculatus | --- | 0 | --- | 0 | --- | 0 | 59 | 38 | --- | 0 | --- | 0 | --- | 0 | --- | 0 |
Vahlia capensis | --- | 0 | --- | 0 | --- | 0 | 46 | 26 | --- | 0 | --- | 3 | --- | 0 | --- | 0 |
Pavetta zeyheri | --- | 6 | --- | 0 | --- | 24 | 44 | 62 | --- | 4 | --- | 18 | --- | 13 | --- | 14 |
Combretum hereroense | --- | 0 | --- | 0 | --- | 0 | 40 | 65 | --- | 16 | 17 | 40 | --- | 34 | --- | 15 |
Colophospermum mopane | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 63 | 55 | --- | 1 | --- | 1 | --- | 11 |
Setaria pumila | --- | 33 | --- | 20 | --- | 14 | --- | 0 | 44 | 78 | --- | 9 | --- | 14 | 13 | 42 |
Aristida congesta subsp. congesta | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 58 | 40 | --- | 1 | --- | 1 |
Waltheria indica | --- | 6 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 50 | 42 | --- | 7 | --- | 5 |
Hyphaene petersiana | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 50 | 47 | 17 | 23 | --- | 4 |
Stipagrostis uniplumis var. uniplumis | --- | 6 | --- | 0 | --- | 0 | --- | 3 | --- | 10 | 49 | 63 | --- | 18 | --- | 26 |
Schizachyrium exile | --- | 6 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 45 | 28 | --- | 0 | --- | 0 |
Kyphocarpa angustifolia | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 4 | 44 | 37 | --- | 7 | --- | 9 |
Schmidtia pappophoroides | --- | 6 | --- | 0 | --- | 5 | --- | 0 | --- | 2 | 43 | 36 | --- | 3 | --- | 4 |
Pogonarthria fleckii | --- | 11 | --- | 0 | --- | 0 | --- | 6 | 23 | 43 | 43 | 63 | --- | 11 | --- | 16 |
Eragrostis rigidior | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 0 | 41 | 29 | --- | 3 | --- | 9 |
Spirostachys africana | --- | 11 | --- | 20 | --- | 14 | --- | 3 | --- | 43 | 26 | 67 | 43 | 89 | --- | 30 |
Kirkia acuminata | 50 | 94 | 54 | 100 | 4 | 38 | --- | 0 | --- | 12 | --- | 1 | --- | 10 | --- | 7 |
Commiphora glaucescens | 47 | 89 | 29 | 67 | 48 | 90 | --- | 0 | --- | 0 | --- | 0 | --- | 3 | --- | 2 |
Terminalia prunioides | --- | 17 | --- | 73 | --- | 76 | --- | 88 | 18 | 98 | 14 | 94 | --- | 90 | --- | 90 |
Dichrostachys cinerea | --- | 78 | --- | 67 | --- | 71 | --- | 35 | --- | 90 | --- | 91 | 16 | 96 | 16 | 95 |
Combretum apiculatum | 17 | 100 | --- | 87 | 12 | 95 | --- | 74 | --- | 88 | 10 | 94 | --- | 52 | --- | 78 |
Grewia bicolor | --- | 44 | --- | 67 | --- | 48 | --- | 62 | --- | 69 | 13 | 83 | 18 | 90 | --- | 78 |
Senegalia mellifera subsp. detinens | --- | 11 | --- | 27 | --- | 67 | --- | 76 | --- | 47 | 20 | 86 | --- | 79 | 21 | 87 |
Commiphora glandulosa | --- | 28 | --- | 67 | --- | 62 | 13 | 79 | 18 | 86 | --- | 72 | --- | 45 | --- | 59 |
Melinis repens subsp. grandiflora | 14 | 83 | --- | 73 | --- | 52 | 13 | 82 | 13 | 82 | --- | 60 | --- | 41 | --- | 53 |
Croton gratissimus | 26 | 100 | 15 | 87 | 26 | 100 | 6 | 76 | --- | 39 | --- | 32 | --- | 52 | --- | 63 |
Urochloa brachyura | --- | 28 | --- | 20 | --- | 10 | --- | 21 | 20 | 71 | 28 | 82 | 23 | 75 | --- | 53 |
Grewia flavescens | --- | 44 | --- | 67 | --- | 19 | --- | 29 | 13 | 63 | --- | 40 | --- | 48 | 9 | 58 |
Vachellia nilotica | --- | 22 | --- | 20 | --- | 48 | --- | 6 | --- | 29 | 18 | 60 | 17 | 59 | 15 | 56 |
Combretum imberbe | --- | 6 | --- | 40 | --- | 52 | 15 | 62 | --- | 45 | 10 | 55 | --- | 45 | --- | 36 |
Vachellia reficiens / luederitzii | --- | 0 | --- | 0 | --- | 48 | --- | 21 | --- | 16 | --- | 38 | 21 | 56 | 27 | 63 |
Brachiaria deflexa | --- | 17 | 27 | 67 | --- | 19 | --- | 3 | --- | 29 | --- | 24 | 21 | 59 | 13 | 50 |
Aristida rhiniochloa | --- | 0 | --- | 0 | --- | 0 | --- | 44 | 22 | 53 | 37 | 71 | --- | 14 | --- | 33 |
Tragus racemosus | --- | 0 | --- | 13 | --- | 24 | --- | 44 | 15 | 47 | --- | 32 | --- | 32 | --- | 36 |
Aristida adscensionis | --- | 33 | --- | 13 | --- | 5 | 23 | 59 | 12 | 45 | 12 | 45 | --- | 24 | --- | 21 |
Enneapogon cenchroides | --- | 6 | --- | 27 | --- | 10 | --- | 44 | --- | 31 | --- | 21 | 16 | 46 | --- | 38 |
Sporobolus panicoides | --- | 22 | --- | 20 | --- | 5 | --- | 6 | 24 | 53 | --- | 36 | --- | 15 | 19 | 47 |
Bidens biternata | 28 | 72 | 28 | 73 | --- | 29 | --- | 0 | 11 | 51 | --- | 9 | --- | 25 | --- | 37 |
Grewia villosa | --- | 22 | --- | 27 | --- | 14 | --- | 12 | --- | 22 | --- | 10 | 29 | 59 | 10 | 37 |
Mundulea sericea | 13 | 56 | --- | 27 | 25 | 71 | 38 | 88 | --- | 18 | --- | 21 | --- | 14 | --- | 18 |
Lantana angolensis | --- | 6 | --- | 7 | 23 | 48 | --- | 3 | --- | 12 | 16 | 40 | --- | 11 | 26 | 50 |
Enneapogon scoparius | --- | 11 | --- | 33 | 26 | 57 | --- | 12 | --- | 24 | --- | 15 | --- | 18 | 15 | 45 |
Aristida effusa | --- | 6 | --- | 33 | --- | 14 | --- | 18 | --- | 29 | --- | 29 | --- | 17 | 10 | 34 |
Melhania acuminata | --- | 11 | --- | 7 | --- | 5 | --- | 3 | --- | 18 | 32 | 50 | --- | 23 | --- | 24 |
Seddera suffruticosa | --- | 0 | --- | 7 | --- | 19 | --- | 6 | --- | 22 | 18 | 36 | --- | 13 | 21 | 39 |
Eragrostis porosa | --- | 6 | --- | 40 | --- | 5 | 20 | 47 | 21 | 49 | --- | 4 | --- | 21 | --- | 27 |
Abutilon austro-africanum | --- | 17 | --- | 7 | --- | 14 | --- | 3 | --- | 20 | --- | 8 | 32 | 52 | 11 | 31 |
Grewia flava | --- | 6 | --- | 0 | --- | 14 | --- | 12 | --- | 12 | 19 | 35 | --- | 7 | 29 | 45 |
Commelina benghalensis | --- | 39 | 24 | 53 | --- | 5 | --- | 0 | 15 | 43 | --- | 9 | --- | 25 | --- | 29 |
Euclea undulata | --- | 22 | --- | 13 | 38 | 67 | --- | 6 | --- | 2 | --- | 18 | 11 | 37 | --- | 26 |
Tephrosia dregeana var. dregeana | --- | 11 | --- | 33 | --- | 19 | --- | 32 | --- | 27 | --- | 24 | --- | 24 | --- | 17 |
Cenchrus ciliaris | --- | 22 | --- | 20 | --- | 38 | --- | 0 | --- | 27 | --- | 4 | --- | 17 | 21 | 44 |
Indigofera charlieriana | --- | 0 | --- | 20 | --- | 19 | --- | 9 | 35 | 57 | --- | 14 | --- | 15 | --- | 27 |
Melhania virescens | --- | 6 | --- | 7 | 35 | 57 | --- | 6 | --- | 24 | --- | 3 | --- | 17 | 22 | 44 |
Pavonia burchellii | --- | 11 | --- | 33 | --- | 38 | --- | 3 | --- | 12 | --- | 12 | --- | 24 | 14 | 37 |
Achyranthes aspera var. sicula | 21 | 50 | 29 | 60 | --- | 10 | --- | 3 | --- | 20 | --- | 6 | 10 | 38 | --- | 20 |
Evolvulus alsinoides | --- | 6 | --- | 7 | --- | 0 | --- | 3 | --- | 20 | 35 | 49 | --- | 17 | --- | 20 |
Eragrostis trichophora | --- | 0 | --- | 7 | --- | 0 | --- | 29 | --- | 6 | 24 | 38 | --- | 18 | --- | 27 |
Gymnosporia senegalensis | --- | 6 | --- | 20 | --- | 38 | --- | 26 | --- | 8 | --- | 22 | 9 | 31 | --- | 18 |
Peltophorum africanum | 28 | 50 | --- | 20 | --- | 10 | --- | 3 | --- | 4 | 19 | 41 | --- | 17 | --- | 20 |
Ocimum americanum var. americanum | --- | 0 | --- | 0 | --- | 5 | 28 | 44 | --- | 8 | 28 | 44 | --- | 15 | --- | 15 |
Ziziphus mucronata | --- | 33 | --- | 13 | 25 | 48 | --- | 0 | --- | 2 | --- | 26 | --- | 23 | --- | 24 |
Otoptera burchellii | --- | 0 | --- | 7 | --- | 24 | --- | 6 | --- | 27 | --- | 23 | --- | 8 | 19 | 35 |
Phyllanthus pentandrus | 15 | 44 | 28 | 60 | --- | 33 | --- | 15 | --- | 20 | --- | 3 | --- | 17 | --- | 24 |
Albizia anthelmintica | --- | 6 | --- | 7 | --- | 0 | --- | 3 | --- | 8 | 19 | 31 | --- | 27 | 16 | 28 |
Ipomoea sinensis | --- | 0 | --- | 7 | --- | 5 | --- | 0 | 38 | 51 | --- | 12 | --- | 20 | 13 | 28 |
Ocimum filamentosum | --- | 28 | --- | 13 | --- | 14 | --- | 0 | 14 | 33 | --- | 8 | --- | 21 | 11 | 30 |
Acalypha segetalis | --- | 28 | 31 | 60 | --- | 29 | --- | 6 | 7 | 33 | --- | 10 | --- | 24 | --- | 11 |
Kohautia aspera | --- | 0 | --- | 7 | --- | 5 | --- | 12 | 36 | 49 | --- | 9 | --- | 11 | 15 | 30 |
Ximenia americana | 36 | 61 | --- | 7 | --- | 29 | --- | 9 | --- | 4 | --- | 18 | 10 | 32 | --- | 13 |
Monechma spartioides | --- | 0 | --- | 0 | --- | 10 | --- | 0 | --- | 6 | 20 | 29 | --- | 23 | 20 | 30 |
Enneapogon desvauxii | --- | 0 | --- | 0 | --- | 14 | --- | 15 | 20 | 33 | --- | 12 | --- | 8 | 21 | 34 |
Sporobolus fimbriatus | --- | 11 | --- | 7 | --- | 10 | --- | 0 | --- | 6 | 39 | 50 | --- | 23 | --- | 7 |
Limeum sulcatum | --- | 6 | --- | 27 | --- | 0 | --- | 12 | 15 | 31 | --- | 15 | --- | 18 | --- | 18 |
Microchloa caffra | --- | 17 | --- | 20 | --- | 14 | 21 | 41 | 12 | 33 | --- | 15 | --- | 6 | --- | 11 |
Flueggea virosa | --- | 11 | 29 | 53 | 15 | 38 | --- | 9 | --- | 24 | --- | 4 | --- | 17 | --- | 18 |
Rhynchosia minima | --- | 22 | --- | 20 | 16 | 33 | --- | 0 | --- | 12 | --- | 6 | --- | 18 | 10 | 28 |
Gisekia africana | --- | 11 | --- | 7 | --- | 0 | 23 | 38 | --- | 24 | --- | 10 | --- | 24 | --- | 11 |
Tragus berteronianus | --- | 0 | --- | 13 | --- | 0 | --- | 3 | 16 | 27 | --- | 17 | --- | 17 | 13 | 23 |
Acrotome inflata | --- | 11 | --- | 0 | --- | 5 | --- | 3 | 18 | 29 | --- | 15 | --- | 20 | --- | 19 |
Pupalia lappacea | --- | 11 | 21 | 40 | --- | 29 | --- | 12 | --- | 2 | --- | 14 | 9 | 28 | --- | 13 |
Helinus integrifolius | --- | 0 | 27 | 40 | --- | 10 | --- | 3 | --- | 12 | --- | 5 | --- | 13 | 22 | 36 |
Eragrostis echinochloidea | --- | 0 | --- | 0 | --- | 29 | 38 | 53 | --- | 10 | --- | 9 | --- | 8 | --- | 21 |
Dicoma tomentosa | --- | 0 | --- | 0 | --- | 0 | --- | 3 | 28 | 35 | 29 | 36 | --- | 8 | --- | 9 |
Rhynchosia totta | --- | 22 | --- | 20 | --- | 14 | --- | 3 | --- | 20 | --- | 18 | --- | 13 | --- | 16 |
Commiphora tenuipetiolata | --- | 22 | --- | 20 | --- | 5 | 32 | 50 | --- | 12 | --- | 13 | --- | 8 | --- | 13 |
Setaria verticillata | --- | 0 | --- | 27 | --- | 0 | --- | 0 | --- | 0 | --- | 14 | 27 | 35 | --- | 20 |
Clerodendrum ternatum | --- | 0 | --- | 13 | --- | 14 | --- | 3 | --- | 14 | 12 | 23 | --- | 8 | 13 | 23 |
Panicum maximum | 29 | 44 | --- | 20 | --- | 5 | --- | 3 | --- | 0 | --- | 17 | 15 | 31 | --- | 11 |
Eragrostis lehmanniana | 28 | 44 | --- | 13 | --- | 14 | --- | 3 | --- | 18 | --- | 13 | --- | 15 | --- | 14 |
Sericorema sericea | --- | 0 | --- | 0 | --- | 5 | 18 | 29 | 27 | 37 | --- | 8 | --- | 10 | --- | 16 |
Hibiscus caesius | --- | 0 | --- | 13 | --- | 29 | --- | 0 | --- | 4 | --- | 9 | --- | 15 | 19 | 29 |
Croton menyharthii | --- | 0 | --- | 7 | --- | 0 | --- | 6 | --- | 12 | --- | 18 | 31 | 37 | --- | 7 |
Sclerocarya birrea subsp. caffra | 26 | 50 | 35 | 60 | --- | 10 | --- | 12 | --- | 18 | --- | 10 | --- | 10 | --- | 6 |
Aristida stipoides | --- | 6 | --- | 13 | --- | 10 | 40 | 53 | --- | 4 | --- | 18 | --- | 7 | --- | 10 |
Blepharis obmitrata | --- | 6 | --- | 20 | --- | 19 | --- | 0 | --- | 10 | --- | 5 | --- | 17 | 13 | 24 |
Erucastrum arabicum | --- | 6 | --- | 27 | --- | 10 | --- | 0 | --- | 18 | --- | 0 | 11 | 23 | 10 | 21 |
Hibiscus calyphyllus | --- | 6 | 25 | 33 | --- | 5 | --- | 0 | --- | 4 | --- | 1 | --- | 14 | 25 | 34 |
Asparagus nelsii | --- | 11 | --- | 20 | 32 | 48 | --- | 0 | --- | 18 | --- | 13 | --- | 7 | --- | 14 |
Commiphora africana | --- | 0 | 24 | 40 | 22 | 38 | --- | 6 | --- | 14 | --- | 6 | --- | 13 | --- | 16 |
Andropogon chinensis | 37 | 61 | --- | 0 | 33 | 57 | --- | 18 | --- | 18 | --- | 6 | --- | 1 | --- | 7 |
Brachiaria malacodes | --- | 6 | 20 | 33 | --- | 24 | --- | 6 | --- | 12 | --- | 4 | --- | 11 | 6 | 20 |
Digitaria velutina | --- | 0 | 26 | 33 | --- | 0 | --- | 0 | --- | 8 | --- | 4 | 20 | 28 | --- | 18 |
Enteropogon macrostachyus | --- | 17 | --- | 13 | --- | 10 | --- | 0 | --- | 10 | --- | 8 | 12 | 23 | --- | 15 |
Grewia olukondae | 26 | 33 | --- | 7 | --- | 0 | --- | 3 | --- | 0 | 24 | 32 | --- | 14 | --- | 4 |
Asparagus exuvialis | --- | 0 | --- | 27 | --- | 10 | --- | 6 | --- | 2 | 14 | 23 | --- | 14 | --- | 9 |
Pentarrhinum insipidum | 29 | 44 | --- | 7 | 28 | 43 | --- | 0 | --- | 8 | --- | 1 | --- | 10 | --- | 14 |
Setaria sagittifolia | --- | 0 | 26 | 33 | --- | 5 | --- | 0 | --- | 2 | --- | 8 | 34 | 39 | --- | 3 |
Bothriochloa radicans | --- | 0 | --- | 0 | --- | 0 | --- | 3 | 24 | 24 | --- | 4 | --- | 10 | 18 | 20 |
Hermannia modesta | --- | 0 | --- | 7 | --- | 14 | 21 | 29 | 13 | 22 | --- | 1 | --- | 3 | --- | 14 |
Chloris virgata | --- | 0 | --- | 0 | --- | 0 | --- | 3 | --- | 16 | --- | 9 | --- | 10 | 18 | 19 |
Phyllanthus maderaspatensis | --- | 11 | --- | 7 | --- | 0 | --- | 15 | --- | 4 | --- | 15 | --- | 11 | --- | 11 |
Gymnema sylvestre | --- | 17 | --- | 20 | --- | 10 | --- | 3 | --- | 12 | --- | 12 | --- | 13 | --- | 7 |
Ximenia caffra | 14 | 28 | --- | 27 | 20 | 33 | --- | 0 | --- | 2 | --- | 8 | --- | 8 | --- | 11 |
Spermacoce senensis | --- | 17 | 23 | 33 | --- | 5 | --- | 0 | 13 | 24 | --- | 10 | --- | 6 | --- | 7 |
Euphorbia inaequilatera | --- | 0 | --- | 0 | --- | 5 | --- | 0 | 39 | 37 | --- | 4 | --- | 10 | --- | 11 |
Aptosimum decumbens | --- | 0 | --- | 0 | --- | 0 | --- | 3 | --- | 14 | 15 | 17 | --- | 1 | 18 | 18 |
Megalochlamys marlothii | --- | 0 | --- | 0 | --- | 0 | --- | 0 | --- | 18 | --- | 1 | --- | 11 | 24 | 22 |
Solanum delagoense | --- | 11 | --- | 7 | --- | 14 | --- | 0 | --- | 12 | --- | 5 | --- | 3 | 16 | 21 |
Overview of the Terminalietea prunioidis:
5.1 Commiphoro glaucescentis-Kirkietalia acuminatae
5.1.1 Commiphoro glaucescentis-Kirkion acuminatae
5.1.1.1 Lanneo discoloris-Kirkietum acuminatae
5.1.1.2 Commiphoro glaucescentis-Kirkietum acuminatae
5.1.1.3 Commiphoro glaucescentis-Combretetum apiculati
5.2 Terminalietalia prunioidis
5.2.1 Unnamed group
5.2.1.1 Trago pedunculati-Ipomoeetum adenioidis
5.2.1.2 Combreto apiculati-Colophospermetum mopane
5.2.2 Terminalio prunioidis-Hyphaenion petersianae
5.2.2.1 Terminalio prunioidis-Hyphaenetum petersianae
5.2.3 Dichrostachyo cinereae-Terminalion prunioidis
5.2.3.1 Terminalio prunioidis-Spirostachyetum africanae
5.2.3.2 Dichrostachyo cinereae-Terminalietum prunioidis
5.1 Commiphoro glaucescentis - Kirkietalia acuminatae ord. nov.
Number of relevés: 54
Holotypus: Commiphoro glaucescentis-Kirkion acuminatae B. Strohbach & M. Strohbach 2023 (see below)
Number of species observed: 228
Diagnostic species: Commiphora glaucescens, Kirkia acuminata, Dombeya rotundifolia, Danthoniopsis dinteri
Constant species: Combretum apiculatum
The Commiphoro glaucescentis-Kirkietalia acuminatae represent the mountain vegetation of the Karstveld. Various forms are known from as far afield as the Opuwo district in north-western Namibia (
5.1.1 Commiphoro glaucescentis - Kirkion acuminatae all. nov.
Number of relevés: 54
Type: Commiphoro glaucescentis-Kirkietum acuminatae B. Strohbach & M. Strohbach 2023 (see below)
Number of species observed: 228
Diagnostic species: Commiphora glaucescens, Kirkia acuminata, Dombeya rotundifolia, Danthoniopsis dinteri
Constant species: Combretum apiculatum
5.1.1.1 Lanneo discoloris - Kirkietum acuminatae ass. nov.
Number of relevés: 18
Number of species observed: 149
Estimated number of species: 259
Average species density in 1000 m2: 41
Type relevé: 7943 (holotypus), sampled on 15 February 2008 at 19.45389°S, 17.66972°E (Mosbach)
Kirkia acuminata (t2) 10%, Lannea discolor (t2) 10%, Spirostachys africana (t2) 5%, Sclerocarya birrea subsp. caffra (t2) 0.5%, Combretum apiculatum subsp. leutweinii (t3) 5%, Dichrostachys cinerea (t3) 5%, Peltophorum africanum (t3) 5%, Spirostachys africana (t3) 5%, Commiphora glandulosa (t3) 1%, Commiphora tenuipetiolata (t3) 0.5%, Croton gratissimus var. subgratissimus (s1) 10%, Flueggea virosa (s1) 5%, Grewia flavescens (s1) 5%, Dombeya rotundifolia (s1) 2%, Mundulea sericea (s1) 1%, Ximenia americana (s1) 1%, Cissus nymphaeifolia (s1) 0.5%, Commiphora glaucescens (s1) 0.5%, Euphorbia guerichiana (s1) 0.5%, Ozoroa insignis (s1) 0.5%, Terminalia sericea (s1) 0.5%, Vachellia nilotica (s1) 0.5%, Vangueria infausta (s1) 0.5%, Ximenia caffra (s1) 0.5%, Cyphostemma congestum (s2) 0.5%, Grewia villosa (s2) 0.5%, Securidaca longepedunculata (s2) 0.5%, Panicum maximum (gp) 20%, Digitaria seriata (gp) 5%, Heteropogon contortus (gp) 1%, Cenchrus ciliaris (gp) 0.5%, Enneapogon scoparius (gp) 0.5%, Enteropogon macrostachyus (gp) 0.5%, Eragrostis lehmanniana (gp) 0.5%, Eustachys paspaloides (gp) 0.5%, Danthoniopsis dinteri (ga) 10%, Brachiaria deflexa (ga) 0.5%, Enneapogon cenchroides (ga) 0.5%, Melinis repens subsp. grandiflora (ga) 0.5%, Tephrosia purpurea (ga) 0.5%, Cheilanthes marlothii (hl) 2%, Hypoestes forskaolii (hl) 2%, Bidens biternata (hl) 1%, Cheilanthes dinteri (hl) 1%, Cleome monophylla (hl) 1%, Pellaea calomelanos (hl) 1%, Abutilon angulatum (hl) 0.5%, Acalypha segetalis (hl) 0.5%, Cardiospermum corindum (hl) 0.5%, Cheilanthes involuta (hl) 0.5%, Commelina benghalensis (hl) 0.5%, Erucastrum arabicum (hl) 0.5%, Hibiscus calyphyllus (hl) 0.5%, Hibiscus castroi (hl) 0.5%, Kyllinga alba (hl) 0.5%, Momordica balsamina (hl) 0.5%, Ocimum filamentosum (hl) 0.5%, Oxalis purpurascens (hl) 0.5%, Pavonia burchellii (hl) 0.5%, Pentarrhinum insipidum (hl) 0.5%, Phyllanthus pentandrus (hl) 0.5%, Pupalia lappacea (hl) 0.5%, Rhynchosia venulosa (hl) 0.5%, Solanum lichtensteinii (hl) 0.5%, Talinum caffrum (hl) 0.5%, Tragia okanyua (hl) 0.5%
Diagnostic species: Vangueria infausta, Pellaea calomelanos, Cheilanthes dinteri, Lannea discolor, Cleome monophylla, Kirkia acuminata, Macrotyloma axillare, Commiphora glaucescens, Ozoroa insignis, Andropogon gayanus var. polycladus, Merremia pinnata, Thunbergia aurea, Danthoniopsis dinteri, Ipomoea verbascoidea
Constant species: Croton gratissimus, Combretum apiculatum, Melinis repens subsp. grandiflora, Dichrostachys cinerea, Dombeya rotundifolia, Bidens biternata, Ximenia americana, Andropogon chinensis
The Lanneo discoloris-Kirkietum acuminatae forms a tall, sub-continuous thicket dominated by the phanerophytes Kirkia acuminata, Croton gratissimus, Combretum apiculatum, Commiphora glaucescens and Lannea discolor. The grass sward consists of Danthoniopsis dinteri, Panicum maximum, Melinis repens subsp. grandiflora, Eragrostis porosa, Digitaria seriata and Aristida adscensionis (Figures
Typical structure of the associations of the Terminalietea prunioidis: (a) Lanneo discoloris-Kirkietum acuminatae; (b) Commiphoro glaucescentis-Kirkietum acuminatae; (c) Commiphoro glaucescentis-Combretetum apiculati; (d) Trago pedunculati-Ipomoeetum adenioidis; (e) Combreto apiculati-Colophospermetum mopane; (f) Terminalio prunioidis-Hyphaenetum petersianae; (g) Terminalio prunioidis-Spirostachyetum africanae; (h) Dichrostachyo cinereae-Terminalietum prunioidis.
Typical views of the associations of the Terminalietea prunioidis: (a) Lanneo discoloris-Kirkietum acuminatae, relevé 7951; (b) Commiphoro glaucescentis-Kirkietum acuminatae, relevé 7934; (c) Commiphoro glaucescentis-Combretetum apiculati, relevé 7971; (d) Trago pedunculati-Ipomoeetum adenioidis, relevé 2794; (e) Trago pedunculati-Ipomoeetum adenioidis during the peak rainy season; (f) Combreto apiculati-Colophospermetum mopane, relevé 8071; (g) Terminalio prunioidis-Hyphaenetum petersianae, relevé 2793; (h) Terminalio prunioidis-Spirostachyetum africanae, relevé 7771; (i) Dichrostachyo cinereae-Terminalietum prunioidis, relevé 8113.
The association occurs on moderately steep to steep mountain slopes, mostly of the Nosib Group and Abenab Subgroup type rocks (i.e. quarzites, dolomites, limestone, conglomerate). Large stones (20–60 cm) cover between 15 and 40% of the soil surface, whilst rocks (i.e. bigger than 60 cm) cover between 40 and 80%, sometimes even more. The soils are shallow (<30 cm deep) and medium-textured (
5.1.1.2 Commiphoro glaucescentis - Kirkietum acuminatae ass. nov.
Number of relevés: 15
Number of species observed: 156
Estimated number of species: 285
Average species density in 1000 m2: 44
Type relevé: 8018 (holotypus), sampled on 14 March 2008 at 19.46250°S, 16.90139°E (Olifantspoor)
Kirkia acuminata (t1) 20%, Sclerocarya birrea subsp. caffra (t1) 1%, Berchemia discolor (t2) 10%, Terminalia prunioides (t2) 10%, Commiphora mollis (t2) 1%, Commiphora glaucescens (t3) 10%, Commiphora mollis (t3) 10%, Combretum apiculatum subsp. apiculatum (s1) 10%, Senegalia erubescens (s1) 10%, Flueggea virosa (s1) 5%, Grewia bicolor (s1) 2%, Cissus nymphaeifolia (s1) 1%, Steganotaenia araliacea var. araliacea (s2) 0.5%, Triraphis ramosissima (gp) 1%, Danthoniopsis dinteri (ga) 5%, Brachiaria deflexa (ga) 2%, Melinis repens subsp. grandiflora (ga) 2%, Dactyloctenium aegyptium (ga) 1%, Eragrostis porosa (ga) 1%, Setaria sagittifolia (ga) 0.5%, Achyranthes aspera var. sicula (hl) 10%, Commelina benghalensis (hl) 10%, Bidens biternata (hl) 5%, Momordica humilis (hl) 5%, Acalypha ciliata (hl) 1%, Abutilon angulatum (hl) 0.5%, Actiniopteris radiata (hl) 0.5%, Cleome angustifolia subsp. diandra (hl) 0.5%, Corchorus tridens (hl) 0.5%, Crassocephalum coeruleum (hl) 0.5%, Gisekia africana (hl) 0.5%, Hibiscus elliottiae (hl) 0.5%, Ipomoea dichroa (hl) 0.5%, Neorautanenia mitis (hl) 0.5%, Phyllanthus pentandrus (hl) 0.5%, Rhynchosia totta (hl) 0.5%, Schkuhria pinnata (hl) 0.5%, Spermacoce senensis (hl) 0.5%, Thunbergia aurea (hl) 0.5%
Diagnostic species: Danthoniopsis dinteri, Cissus nymphaeifolia, Steganotaenia araliacea var. araliacea, Kirkia acuminata, Ficus cordata, Crassocephalum coeruleum, Actiniopteris radiata, Berchemia discolor, Triraphis ramosissima, Momordica humilis
Constant species: Croton gratissimus, Combretum apiculatum, Terminalia prunioides, Melinis repens subsp. grandiflora, Bidens biternata, Grewia flavescens, Grewia bicolor, Dichrostachys cinerea, Commiphora glaucescens, Commiphora glandulosa, Brachiaria deflexa
The Commiphoro glaucescentis-Kirkietum acuminatae forms a tall, sub-continuous thicket, dominated by the phanerophytes Kirkia acuminata, Commiphora glaucescens, Gyrocarpus americanus subsp. africanus, Croton gratissimus and Commiphora mollis. The grass sward is less diverse, with Danthoniopsis dinteri and Brachiaria malacodes dominating. Plectranthus cylindraceus (a leaf-succulent suffrutex) is also common (Figures
This association occurs on steep to very steep mountain slopes, mostly of the Tsumeb Subgroup rocks (mostly dolomites). Stone and rock cover is equally high as with the Lanneo discoloris-Kirkietum acuminatae, however more medium-sized stones (5 – 20 cm) are present. The association occurs at altitudes between 1250 and 1640 m a.s.l.
5.1.1.3 Commiphoro glaucescentis - Combretetum apiculati ass. nov.
Number of relevés: 21
Number of species observed: 131
Estimated number of species: 225
Average species density in 1000 m2: 40
Type relevé: 7910 (holotypus), sampled on 12 February 2008 at 19.54833°S, 17.46556°E (Ma Foi)
Ficus burkei (t2) 1%, Commiphora glaucescens (t3) 10%, Combretum apiculatum subsp. apiculatum (s1) 10%, Dichrostachys cinerea (s1) 10%, Senegalia mellifera subsp. detinens (s1) 10%, Terminalia prunioides (s1) 10%, Croton gratissimus var. subgratissimus (s1) 5%, Dombeya rotundifolia (s1) 5%, Elephantorrhiza suffruticosa (s1) 5%, Grewia flava (s1) 1%, Commiphora africana (s1) 0.5%, Flueggea virosa (s1) 0.5%, Gymnosporia senegalensis (s1) 0.5%, Lantana angolensis (s1) 0.5%, Searsia marlothii (s1) 0.5%, Ziziphus mucronata (s1) 0.5%, Cissus nymphaeifolia (s1) 0.1%, Aerva leucura (s2) 0.5%, Mundulea sericea (s2) 0.5%, Ehretia rigida (s2) 0.1%, Grewia bicolor (s2) 0.1%, Eragrostis nindensis (gp) 5%, Eragrostis lehmanniana var. lehmanniana (gp) 2%, Andropogon chinensis (gp) 0.5%, Heteropogon contortus (gp) 0.5%, Oropetium capense (gp) 0.5%, Melinis repens subsp. grandiflora (ga) 0.5%, Actiniopteris radiata (hl) 2%, Cyperus cuspidatus (hl) 1%, Bidens biternata (hl) 0.5%, Cheilanthes marlothii (hl) 0.5%, Clerodendrum ternatum (hl) 0.5%, Dipcadi glaucum (hl) 0.5%, Hibiscus caesius (hl) 0.5%, Ophioglossum polyphyllum (hl) 0.5%, Pavonia burchellii (hl) 0.5%, Pentarrhinum insipidum (hl) 0.5%, Phyllanthus pentandrus (hl) 0.5%, Rhynchosia venulosa (hl) 0.5%, Scadoxus multiflorus (hl) 0.5%, Eriospermum flagelliforme (hl) 0.1%, Gloriosa superba (hl) 0.1%, Enneapogon scoparius (gp) 10%, Fingerhuthia africana (gp) 10%, Anthephora pubescens (gp) 5%
Diagnostic species: Fingerhuthia africana, Searsia marlothii, Commiphora glaucescens, Dombeya rotundifolia, Anthephora pubescens, Eragrostis nindensis, Heteropogon contortus, Ophioglossum polyphyllum
Constant species: Croton gratissimus, Combretum apiculatum, Terminalia prunioides, Mundulea sericea, Dichrostachys cinerea, Senegalia mellifera subsp. detinens, Euclea undulata, Commiphora glandulosa
The Commiphoro glaucescentis-Combretetum apiculati forms a short, moderately closed thicket dominated by the phanerophytes Terminalia prunioides, Croton gratissimus, Commiphora glaucescens, Spirostachys africana, Kirkia acuminata, Dombeya rotundifolia, Dichrostachys cinerea and Combretum apiculatum. Opuntia ficus-indica has been found to be a common invader in this association. The grass sward is best developed of the three mountain associations, being dominated by Eragrostis nindensis, Enneapogon scoparius, Heteropogon contortus, Eragrostis scopelophila and Enneapogon desvauxii (Figures
This association is occurring on low hills and ridges as well as on mountain peaks, at a wide range of altitudes, between 1440 and 2020 m a.s.l., and on both the Abenab and Tsumeb Subgroups. The habitat is however less steep, being rolling to moderately steep. The substrate is also more fragmented, with gravel (0.2–2 cm) and small stones (2–5 cm) and medium stones prominently occurring on the soil surface (2%, 5% and up to 15%, respectively). Large stones and rocks cover about 40% of the soil surface. The soils are equally shallow as with the other mountain habitats.
5.2 Terminalietalia prunioidis ord. nov.
Number of relevés: 329
Type: Dichrostachyo cinereae-Terminalion prunioidis B. Strohbach & M. Strohbach 2023 (see below)
Number of species observed: 412
Diagnostic species: Aristida rhiniochloa, Urochloa brachyura, Combretum hereroense, Senegalia mellifera subsp. detinens, Terminalia prunioides
Constant species: Dichrostachys cinerea, Grewia bicolor, Combretum apiculatum, Commiphora glandulosa, Melinis repens subsp. grandiflora, Croton gratissimus, Spirostachys africana, Grewia flavescens, Vachellia nilotica, Combretum imberbe, Vachellia reficiens / luederitzii
The Terminalietalia prunioidis are subdivided into three groups, of which the latter two are recognised as alliances. The Dichrostachyo cinereae-Terminalion prunioidis is designated as the type for this order. The Terminalietalia prunioidis represent the Karstveld plains to the north of the Otavi Mountain Range. The first group is characterised by the occurrence of Anthephora schinzii together with Terminalia prunioides, Commiphora glandulosa, Combretum apiculatum and Melinis repens subsp. grandiflora. Two associations have been classified into this group. However, as the composition and habitats of these two groups vary widely, they cannot be grouped into an alliance.
5.2.1.1 Trago pedunculati - Ipomoeetum adenioidis ass. nov.
Number of relevés: 34
Number of species observed: 75
Estimated number of species: 176
Average species density in 1000 m2: 26
Type relevé: 2794 (holotypus), sampled on 3 April 2003 at 19.25611°S, 18.48389°E (Baden)
Terminalia prunioides (t3) 2%, Terminalia prunioides (s1) 10%, Combretum apiculatum subsp. apiculatum (s1) 2%, Senegalia mellifera subsp. detinens (s1) 2%, Combretum hereroense (s1) 1%, Croton gratissimus var. gratissimus (s1) 1%, Grewia bicolor (s1) 1%, Pavetta zeyheri (s1) 1%, Rhigozum brevispinosum (s1) 1%, Ipomoea adenioides (s2) 2%, Mundulea sericea (s2) 2%, Stipagrostis uniplumis var. uniplumis (gp) 2%, Eragrostis echinochloidea (gp) 1%, Oropetium capense (gp) 1%, Anthephora schinzii (ga) 5%, Aristida adscensionis (ga) 1%, Eragrostis porosa (ga) 1%, Melinis repens subsp. grandiflora (ga) 1%, Tragus pedunculatus (ga) 1%, Gisekia africana (hl) 1%, Hermannia modesta (hl) 1%, Phyllanthus maderaspatensis (hl) 1%, Tephrosia dregeana var. dregeana (hl) 1%
Diagnostic species: Anthephora schinzii, Ipomoea adenioides, Tragus pedunculatus, Vahlia capensis, Pavetta zeyheri
Constant species: Terminalia prunioides, Mundulea sericea, Melinis repens subsp. grandiflora, Commiphora glandulosa, Senegalia mellifera subsp. detinens, Croton gratissimus, Combretum apiculatum, Combretum hereroense, Grewia bicolor, Combretum imberbe
The Trago pedunculati-Ipomoeetum adenioidis forms a short, semi-open bushland dominated by Terminalia prunioides, Senegalia mellifera subsp. detinens and Combretum apiculatum. The grass sward is relatively sparse, being dominated by Melinis repens subsp. grandiflora, Anthephora schinzii, Tragus berteronianus, Panicum coloratum, Eragrostis pilgeriana and Eragrostis nindensis (Figures
The habitat of this association is formed by denuded plates of calcrete, often associated with slight depressions, or, e.g. along the B6 trunk road, associated with a slight rise in topography forming a natural dam causing water to accumulate. This results in temporary flooding and water logging during the peak rainy season (Figure
5.2.1.2 Combreto apiculati - Colophospermetum mopane ass. nov.
Number of relevés: 49
Number of species observed: 190
Estimated number of species: 305
Average species density in 1000 m2: 41
Type relevé: 8022 (holotypus), sampled on 14 March 2008 at 19.50250°S, 16.93444°E (Derna)
Colophospermum mopane (t1) 5%, Spirostachys africana (t2) 1%, Colophospermum mopane (t3) 60%, Terminalia prunioides (t3) 20%, Combretum apiculatum subsp. apiculatum (s1) 5%, Grewia bicolor (s1) 5%, Senegalia cinerea (s1) 5%, Dichrostachys cinerea (s1) 2%, Croton gratissimus var. gratissimus (s1) 1%, Croton menyharthii (s1) 1%, Grewia avellana (s1) 1%, Megalochlamys marlothii (s2) 0.5%, Bothriochloa radicans (gp) 2%, Enteropogon macrostachyus (gp) 2%, Enneapogon scoparius (gp) 0.5%, Microchloa caffra (gp) 0.5%, Aristida rhiniochloa (ga) 2%, Eragrostis porosa (ga) 2%, Setaria pumila (ga) 2%, Aristida effusa (ga) 1%, Melinis repens subsp. grandiflora (ga) 1%, Sporobolus panicoides (ga) 1%, Brachiaria deflexa (ga) 0.5%, Abutilon austro-africanum (hl) 0.5%, Bidens biternata (hl) 0.5%, Hibiscus calyphyllus (hl) 0.5%, Hibiscus elliottiae (hl) 0.5%, Indigastrum parviflorum (hl) 0.5%, Ipomoea sinensis (hl) 0.5%, Ocimum filamentosum (hl) 0.5%, Ruellia prostrata (hl) 0.5%
Diagnostic species: Colophospermum mopane
Constant species: Terminalia prunioides, Dichrostachys cinerea, Combretum apiculatum, Commiphora glandulosa, Melinis repens subsp. grandiflora, Setaria pumila, Urochloa brachyura, Grewia bicolor, Grewia flavescens
The Combreto apiculati-Colophospermetum mopane forms a short, moderately closed bushland, dominated by the phanerophytes Terminalia prunioides, Colophospermum mopane, Dichrostachys cinerea, Combretum apiculatum and Commiphora glandulosa. The grass sward consists of Eragrostis nindensis, Setaria pumila, Eragrostis porosa, Enneapogon desvauxii, Urochloa brachyura, Enneapogon cenchroides and Anthephora schinzii. The annual herb Sericorema sericea and sedges Cyperus hamulosus and Eleocharis atropurpurea are also conspicuous in this association (Figures
Le Roux (
The occurrence of Colophospermum mopane is not restricted to the Combreto apiculati-Colophospermetum mopane. The species occurs intermittently within the Dichrostachyo cinereae-Terminalietum prunioidis to the west and north-west of Tsumeb, gradually increasing in abundance. Anecdotal evidence has it that the species occurred far more east of its present distribution area, but over-utilisation for construction timber and especially mine props in the Tsumeb Mine during the early previous Century led to the gradual retreat of the species to the west.
5.2.2 Terminalio prunioidis-Hyphaenion petersianae all. nov.
Synopsis:
Number of relevés: 78
Type: Terminalio prunioidis-Hyphaenetum petersianae B. Strohbach & M. Strohbach 2023 (see below)
Number of species observed: 216
This alliance consists of a single association, which also serves as its type.
5.2.2.1 Terminalio prunioidis-Hyphaenetum petersianae ass. nov.
Number of relevés: 78
Number of species observed: 216
Estimated number of species: 376
Average species density in 1000 m2: 40
Type relevé: 2793 (holotypus), sampled on 3 April 2003 at 19.21833°S, 18.52417°E (Elandslaagte)
Hyphaene petersiana (t2) 1%, Spirostachys africana (t2) 1%, Commiphora glandulosa (t3) 1%, Terminalia prunioides (s1) 40%, Combretum apiculatum subsp. apiculatum (s1) 5%, Dichrostachys cinerea (s1) 5%, Peltophorum africanum (s1) 5%, Vachellia nilotica (s1) 5%, Grewia bicolor (s1) 2%, Hyphaene petersiana (s1) 2%, Senegalia mellifera subsp. detinens (s1) 2%, Albizia anthelmintica (s1) 1%, Grewia flava (s1) 1%, Ximenia caffra (s1) 1%, Ziziphus mucronata subsp. mucronata (s1) 1%, Aristida congesta (gp) 1%, Eragrostis trichophora (gp) 1%, Heteropogon contortus (gp) 1%, Sporobolus fimbriatus (gp) 1%, Stipagrostis uniplumis var. uniplumis (gp) 1%, Urochloa brachyura (ga) 5%, Aristida adscensionis (ga) 2%, Aristida effusa (ga) 2%, Brachiaria deflexa (ga) 2%, Aristida rhiniochloa (ga) 1%, Digitaria velutina (ga) 1%, Enneapogon cenchroides (ga) 1%, Melinis repens subsp. grandiflora (ga) 1%, Sporobolus panicoides (ga) 1%, Tragus racemosus (ga) 1%, Pogonarthria fleckii (ga) 0.1%, Monechma spartioides (hl) 5%, Evolvulus alsinoides (hl) 1%, Indigofera charlieriana (hl) 1%, Limeum fenestratum (hl) 1%, Melhania acuminata (hl) 1%, Ocimum americanum var. americanum (hl) 1%, Otoptera burchellii (hl) 1%, Phyllanthus maderaspatensis (hl) 1%, Pupalia lappacea (hl) 1%, Rhynchosia venulosa (hl) 1%, Seddera suffruticosa (hl) 1%, Talinum crispatulum (hl) 1%, Tephrosia dregeana var. dregeana (hl) 1%
Diagnostic species: Aristida congesta subsp. congesta, Hyphaene petersiana, Waltheria indica, Stipagrostis uniplumis var. uniplumis, Sporobolus fimbriatus, Schmidtia pappophoroides, Pogonarthria fleckii, Schizachyrium exile, Kyphocarpa angustifolia, Eragrostis rigidior, Aristida rhiniochloa, Evolvulus alsinoides
Constant species: Terminalia prunioides, Combretum apiculatum, Dichrostachys cinerea, Senegalia mellifera subsp. detinens, Grewia bicolor, Urochloa brachyura, Commiphora glandulosa, Spirostachys africana, Vachellia nilotica
The Terminalio prunioidis-Hyphaenetum petersianae forms a tall, sub-continuous thicket dominated by the phanerophytes Terminalia prunioides, Combretum apiculatum, Spirostachys africana, Senegalia mellifera subsp. detinens, Dichrostachys cinerea, Vachellia reficiens / luederitzii, Vachellia nilotica, Hyphaene petersiana, Croton gratissimus and Commiphora glandulosa. The grass sward is dominated by Pogonarthria fleckii, Aristida congesta subsp. congesta, Schizachyrium exile, Aristida rhiniochloa, Urochloa brachyura, Eragrostis trichophora, Eragrostis rigidior, Cymbopogon caesius, Chrysopogon nigritanus and Aristida effusa. The leaf succulent Sansevieria pearsonii is also conspicuous in this association (Figures
The Terminalio prunioidis-Hyphaenetum petersianae forms a distinct zone between the eastern, north-eastern and southern plains and the adjacent riverine habitats (Omuramba Ovambo and Omuramba Omatako). This is locally referred to as the ‘Palmvlakte´ (‘palm plains’, referring to the presence of the makalani palm, Hyphaene petersiana). Hyphaene petersiana is known to occur in soils with a shallow water table, e.g. along the fringes of the Oshana system in central-northern Namibia (
5.2.3 Dichrostachyo cinereae-Terminalion prunioidis all. nov.
Number of relevés: 169
Type: Dichrostachyo cinereae-Terminalietum prunioidis B. Strohbach & M. Strohbach 2023 (see below)
Number of species observed: 316
Constant species: Dichrostachys cinerea, Terminalia prunioides, Senegalia mellifera subsp. detinens, Grewia bicolor, Combretum apiculatum, Urochloa brachyura, Vachellia reficiens / luederitzii, Croton gratissimus, Vachellia nilotica, Spirostachys africana, Grewia flavescens, Brachiaria deflexa, Commiphora glandulosa, Melinis repens subsp. grandiflora, Grewia villosa, Enneapogon cenchroides
No diagnostic species were identified.
This order, representing the Karstveld plains to the east, north and west of the Otavi mountain range, are characterised by the constant occurrence of Dichrostachys cinerea, Terminalia prunioides, Senegalia mellifera subsp. detinens, Grewia bicolor, Combretum apiculatum and Urochloa brachyura. Two associations were identified under this alliance.
5.2.3.1 Terminalio prunioidis-Spirostachyetum africana e le Roux ex B. Strohbach & M. Strohbach ass. nov.
Number of relevés: 71
Number of species observed: 185
Estimated number of species: 356
Average species density in 1000 m2: 35
Type relevé: 8062 (holotypus), sampled on 17 March 2008 at 18.90972°S, 17.23694°E (Onkoshi)
Spirostachys africana (t2) 10%, Terminalia prunioides (t2) 10%, Vachellia luederitzii (t3) 5%, Albizia anthelmintica (t3) 1%, Terminalia prunioides (t3) 1%, Dichrostachys cinerea (s1) 10%, Senegalia mellifera subsp. detinens (s1) 10%, Terminalia prunioides (s1) 10%, Croton gratissimus var. subgratissimus (s1) 5%, Vachellia nilotica (s1) 5%, Grewia bicolor (s1) 2%, Grewia villosa (s1) 2%, Croton menyharthii (s2) 10%, Eragrostis porosa (ga) 10%, Enneapogon cenchroides (ga) 2%, Brachiaria deflexa (ga) 1%, Setaria sagittifolia (ga) 1%, Setaria verticillata (ga) 1%, Urochloa brachyura (ga) 1%, Chloris pycnothrix (ga) 0.5%, Digitaria velutina (ga) 0.5%, Melinis repens subsp. grandiflora (ga) 0.5%, Tragus berteronianus (ga) 0.5%, Tragus racemosus (ga) 0.5%, Erucastrum arabicum (hl) 5%, Achyranthes aspera var. sicula (hl) 2%, Bidens biternata (hl) 2%, Acrotome inflata (hl) 1%, Limeum sulcatum (hl) 1%, Abutilon austro-africanum (hl) 0.5%, Acrachne racemosa (hl) 0.5%, Cucumis anguria (hl) 0.5%, Euphorbia inaequilatera (hl) 0.5%, Hibiscus calyphyllus (hl) 0.5%, Hibiscus elliottiae (hl) 0.5%, Hirpicium gazanioides (hl) 0.5%, Ipomoea sinensis (hl) 0.5%, Kyphocarpa angustifolia (hl) 0.5%, Melhania virescens (hl) 0.5%
Constant species: Dichrostachys cinerea, Terminalia prunioides, Grewia bicolor, Spirostachys africana, Senegalia mellifera subsp. detinens, Urochloa brachyura, Brachiaria deflexa
The same vegetation, dominated by Terminalia prunioides, Spirostachys africana, Dichrostachys cinerea, Urochloa brachyura, Eragrostis porosa, Senegalia mellifera subsp. detinens, Grewia bicolor, Croton gratissimus, Brachiaria deflexa, Croton menyharthii, Vachellia nilotica, Kirkia acuminata, Hypoestes forskaolii, Grewia olukondae, Ficus burkei, Enneapogon desvauxii, Combretum imberbe and Combretum apiculatum occurs widespread as riparian forest in and around the Omuramba Ovambo. In the middle reaches, within the Parkiesveld landscape, the Terminalio prunioidis-Spirostachyetum africanae form distinct tree islands in the grassland matrix formed by the Aristido stipoidis-Willkommietum sarmentosae, often enclosing an ephemeral vley of the Nymphoides indica-Echinochloa pyramidalis community (Figures
5.2.3.2 Dichrostachyo cinereae - Terminalietum prunioidis ass. nov.
Number of relevés: 98
Number of species observed: 291
Estimated number of species: 467
Average species density in 1000 m2: 44
Type relevé: 8104 (holotypus), sampled on 16 April 2008 at 19.15389°S, 17.62694°E (Pasadena)
Vachellia luederitzii (t2) 2%, Terminalia prunioides (t3) 10%, Combretum imberbe (t3) 1%, Commiphora glandulosa (t3) 1%, Commiphora tenuipetiolata (t3) 1%, Terminalia prunioides (s1) 60%, Dichrostachys cinerea (s1) 10%, Combretum apiculatum subsp. apiculatum (s1) 2%, Croton gratissimus var. subgratissimus (s1) 2%, Grewia bicolor (s1) 2%, Peltophorum africanum (s1) 2%, Flueggea virosa (s1) 1%, Montinia caryophyllacea (s1) 1%, Mundulea sericea (s1) 1%, Ozoroa insignis (s1) 1%, Vachellia nilotica (s1) 1%, Ziziphus mucronata (s1) 1%, Spirostachys africana (s1) 0.5%, Solanum tettense var. renschii (s2) 5%, Lantana angolensis (s2) 1%, Ehretia alba (s2) 0.5%, Megalochlamys marlothii (s2) 0.5%, Senegalia mellifera subsp. detinens (s2) 0.5%, Maerua juncea (s2) 0.1%, Cenchrus ciliaris (gp) 2%, Heteropogon contortus (gp) 1%, Enneapogon scoparius (gp) 0.5%, Enteropogon macrostachyus (gp) 0.5%, Eragrostis lehmanniana var. lehmanniana (gp) 0.5%, Eragrostis nindensis (gp) 0.5%, Setaria pumila (ga) 5%, Sporobolus panicoides (ga) 2%, Aristida adscensionis (ga) 1%, Eragrostis porosa (ga) 1%, Urochloa brachyura (ga) 1%, Aristida effusa (ga) 0.5%, Aristida rhiniochloa (ga) 0.5%, Brachiaria malacodes (ga) 0.5%, Enneapogon cenchroides (ga) 0.5%, Enneapogon desvauxii (ga) 0.5%, Melinis repens subsp. grandiflora (ga) 0.5%, Setaria verticillata (ga) 0.5%, Stipagrostis hirtigluma subsp. hirtigluma (ga) 0.5%, Tragus racemosus (ga) 0.5%, Rhynchosia minima (hl) 5%, Kohautia aspera (hl) 2%, Melhania virescens (hl) 2%, Sericorema sericea (hl) 2%, Abutilon austro-africanum (hl) 1%, Acrotome inflata (hl) 1%, Bidens biternata (hl) 1%, Blepharis leendertziae (hl) 1%, Erucastrum arabicum (hl) 1%, Calostephane divaricata (hl) 0.5%, Eriospermum flagelliforme (hl) 0.5%, Euphorbia inaequilatera (hl) 0.5%, Hermannia modesta (hl) 0.5%, Hibiscus caesius (hl) 0.5%, Hirpicium gazanioides (hl) 0.5%, Ipomoea sinensis (hl) 0.5%, Melhania acuminata (hl) 0.5%, Otoptera burchellii (hl) 0.5%, Polygala albida subsp. albida (hl) 0.5%, Seddera suffruticosa (hl) 0.5%, Solanum delagoense (hl) 0.5%, Tephrosia dregeana var. dregeana (hl) 0.5%
Diagnostic species: none
Constant species: Dichrostachys cinerea, Terminalia prunioides, Senegalia mellifera subsp. detinens, Grewia bicolor, Combretum apiculatum, Vachellia reficiens / luederitzii, Croton gratissimus
The Dichrostachyo cinereae-Terminalietum prunioidis forms a short, sub-continuous thicket dominated by the phanerophytes Terminalia prunioides, Dichrostachys cinerea, Senegalia mellifera subsp. detinens, Vachellia reficiens / luederitzii and Croton gratissimus. The grass sward is not well developed and dominated by few perennial and mostly annual species: Enneapogon desvauxii, Urochloa brachyura, Eragrostis porosa, Setaria pumila, Heteropogon contortus, Enteropogon macrostachyus, Pogonarthria fleckii and Aristida adscensionis (Figures
Initial classification results indicated a potential subdivision into three subunits, however the composition differences suggest rather observer and seasonal bias. For this reason, the three subunits have been combined as one.
This association occurs widespread on the plains north, east and west of the Otavi mountain range, often also in the valleys between these mountains. Several relevés have been classified into this association south of the Otavi mountain range, in a mosaic with the Cenchro ciliaris-Senegalietum detinentis and the Eucleo undulatae-Oleetum africanae, emphasising the transitional nature of the northern Thornshrub savanna. The soils are typical mollic Leptosols or leptic Regosols on shallow calcrete. Stone cover varies between 5 and 15% cover, with a general mixture of small, medium and large stones. The landscapes are flat to gently undulating, ranging between 1140 and 1600 m a.s.l.
According to the observed species richness (alpha diversity), the community types fall into three groups (Figure
The gamma diversity indicated similar trends as the species richness (Figure
Biodiversity indicators for the various associations described above. (a) Species richness per relevé sampled on 1000 m2; (b) Gamma diversity for the various associations, indicating both observed and estimated number of species; (c) Simpson’s Index (D) indicating dominance; (d) Smith-Wilson Index (Evar) indicating evenness.
According to the Simpson’s Index, the three wetland types (including the Sporobolo-Odysseetum paucinervis) (1.1, 1.2 and 2.1.1) show a relatively lower degree of dominance (Figure
The NMS produced an ordination in three dimensions, with the final stress for the best solution being 19.6%, and a final instability of 0.00000, after 118 iterations. The randomised data in the Monte Carlo test did not result in a stable solution after 249 iterations. The ordination graph is presented in Figure
From the ordination diagrams it is clear that the Kalahari types favour deep soils, the Thornbush – Karstveld transition types the more sandy soils towards the southern study area, whilst the Terminalietea prunioidis associations are concentrated on mollic soils and/or stony to rocky soils. This is confirmed by the species distribution of some of the characteris phanerophytic species (Figure
To illustrate the distribution of associations within the landscape, classified relevés within two 30 km wide transects (see Figure
Schematic representation of the main vegetation associations across the topographic gradients represented by the transects in Figure
With this paper, we formally describe 17 new associations with two new subassociations within a major landscape, the Karstveld sensu
With continued review of available data and unpublished reports (e.g.
The higher syntaxonomic divisions of the described associations of the Kalahari, Thornbush – Karstveld transistion and wetlands and grasslands remains even more speculative. For the Kalahari vegetation, a good start has been made with the description of the vegetation in the eastern Otjozondjupa and Omaheke Regions (
The vegetation of the Namibian Thornbush savannah is presently under review, and will include the higher syntaxonomic placement of the four associations described as part of the Thornbush – Karstveld transition. A basis for this revision is the earlier work by M.
The higher syntaxonomic placement of the grass- and wetland types stays problematic. The Sporobolus dominated (ishana type) grasslands have been best studied to date, with accounts available from the Etosha Pan halophytic ecoregion, the Cuvelai Basin, the Naye-Naye panveld and also from the Zambezi Region in north-eastern Namibia (
The two mesic grassland associations described here are clearly part of (possibly remnants of?) the Highveld grasslands ecoregion in Souh Africa (
The general lack of syntaxonomical descriptions in neighbouring Botswana and Angola, together with a lack of a comprehensive syntaxonomic overview of especially the grassland and bushveld ecoregions in South Africa, makes a comparision of the present Namibian syntaxonomic classification to similar southern African vegetation difficult.
With 889 observed species within roughly 25,000 km2, the Karstveld is extremely species rich within the arid- to semi-arid Namibian context (
The data used for this publication forms part of the Namibian Phytosociological Database (GVID ID AF-NA-001) and can be provided on request by the corresponding author. The full relevé data is also reproduced in Appendix 1 as phytosociological table. All data of GVID ID AF-NA-001 has been shared with the sPlot database as well as the GBIF database.
B.S. planned the research, B.S. and M.S. conducted the field sampling, M.S. did the initial data analysis and description for the Thornbush savanna, whilst B.S. reanalysed the entire data set and drafted the manuscript. Both authors critically revised the manuscript.
Thanks is due to numerous farmers and landowners who permitted us access to their land and often pointed out interesting features of the vegetation on their property. Unknown species were identified by staff of the National Herbarium of Namibia (WIND), which is gratefully acknowledged. Soil sample analysis was done by the Agricultural Laboratory, Ministry of Agriculture, Water and Forestry, Namibia. Field data collection was co-funded from the recurrent budget of the National Botanical Research Institute, Ministry of Agriculture, Water and Forestry (Vote 2004) and the BIOTA Southern Africa project, as part of the German Federal Ministry of Education and Research (BMBF) research program “Biodiversity and Global Change” (BIOLOG) under their promotion number 01LC0024. The authors are greatful for numerous comments and corrections by unknown reviewers and the editor to improve the quality of the manuscript.
Climate diagrams for several localities within the Karstveld of Namibia
Phytosociological tables of the five major groupings