Life form and species diversity on abandoned croplands, Roggeveld, South Africa
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Date
Authors
Van der Merwe, Helga
Van Rooyen, Margaretha W.
Journal Title
Journal ISSN
Volume Title
Publisher
Taylor & Francis
Abstract
The Roggeveld consists of an island of Mountain Renosterveld (Fynbos biome) surrounded by Succulent Karoo biome vegetation.
Since management of abandoned croplands depends on a better understanding of their succession sequences, vegetation
recovery on abandoned croplands in the Roggeveld was studied using species and life form diversity parameters. Abandoned
croplands of different ages were compared with each other and to the natural vegetation. Therophytes and chamaephytes were
the most abundant life forms. Chamaephytes made an overwhelming contribution to the relative cover. Species-area curves
(exponential function) differed significantly between the abandoned croplands and natural vegetation. Species richness increased
with time since abandonment but no similar increase in species evenness, Shannon or Simpson indices were found. A regression
of species richness against age of abandoned cropland predicted that an abandoned cropland of approximately 33 years should
be as species rich as the natural vegetation, but a principal cooordinate analysis of floristic data indicated that all the plots were
floristically still extremely different from the natural vegetation. Across all nine survey plots only 15 species contributed to a high
cover on the plots. Vegetation recovery on abandoned croplands in the Roggeveld occurs naturally, yet the rate of recovery varies
among the life forms.
Description
Keywords
Vegetation recovery, Abandoned croplands
Sustainable Development Goals
Citation
Van der Merwe, H & Van Rooyen, MC 2012, 'Life form and species diversity on abandoned croplands, Roggeveld, South Africa', African Journal of Range and Forage Science, vol. 28, no. 3, pp. 99-110.