Abstract:
The Soutpansberg Arid Northern Bushveld is one of eight major vegetation types (MVT) described
for the Soutpansberg-Blouberg region. The plant communities of this MVT are described in detail.
Main ecological drivers of the vegetation structure and species composition of these communities
are discussed and some conservation recommendations are made. Phytosociological data from a
subset of 72 Braun-Blanquet sample plots collected in the Soutpansberg Arid Northern Bushveld
were classifi ed using Two-way Indicator Species Analysis (TWINSPAN) and ordinated using
a Detrended Correspondence Analysis (DECORANA). The resulting classifi cation was further
refi ned with table-sorting procedures based on the Braun-Blanquet fl oristic-sociological approach
to vegetation classifi cation using the computer software MEGATAB and JUICE. Eight plant
communities were identifi ed and described as Commiphora tenuipetiolata-Adansonia digitata short
open woodland, Ledebouria ovatifolia-Commiphora mollis short bushland, Phyllanthus reticulatus-
Acacia nigrescens short bushland, Tinnea rhodesiana-Combretum apiculatum short bushland,
Dichrostachys cinerea subsp. africana-Spirostachys africana low thickets, Themeda triandra-Pterocarpus
rotundifolius short closed grassland on steep basaltic slopes, Cyperus albostriatus-Syzygium cordatum
sandveld wetlands, and Sesamothamnus lugardii-Catophractes alexandri tall sparse shrubland.
These plant communities are event-driven ecosystems, predominantly infl uenced by frequent
droughts, exposure to desiccation and unpredictable rainfall events. The complex topography
of the Soutpansberg further contributes to the aridity of these ecosystems. The classifi cation
and ordination analyses show similar groupings in the vegetation of the Soutpansberg Arid
Mountain Bushveld. This confi rms the usefulness of complimentary analysis, using both
classifi cation and ordination methods on a single data set in order to examine patterns and to
search for group structure.
CONSERVATION IMPLICATIONS: The results from this study will alter existing regional vegetation
maps profoundly. The described plant communities of these arid event-driven ecosystems
should be used as benchmark examples of the region’s primary vegetation. Conservation and
management planning should be based on these vegetation units.
