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Do we understand the causes of bush encroachment in African savannas?
  • D. Ward
  • Environmental Science
  • 1 July 2005
Bush encroachment affects the agricultural productivity and biodiversity of 10–20 million ha of South Africa. Many people believe that we understand the causes of bush encroachment. We do not. ManyExpand
A patch-dynamics approach to savanna dynamics and woody plant encroachment – Insights from an arid savanna
It is proposed that woody plant encroachment is part of a cyclical succession between open savanna and woody dominance and is driven by two factors: rainfall that is highly variable in space and time, and inter-tree competition. Expand
Walter’s two-layer hypothesis revisited: back to the roots!
It is found that, within the scope of Walter’s original intentions, this hypothesis works remarkably well, and in some cases is appropriate for deserts as well as for dry temperate systems and even some mesic savannas. Expand
Large mammalian herbivores and the conservation of arid Acacia stands in the Middle East.
It is concluded that large mammalian herbivores are essential components of arid Acacia savannas and that wild and domestic ungulates must be included in future conservation plans. Expand
Multi-scale patterns and bush encroachment in an arid savanna with a shallow soil layer
Question: Bush encroachment (i.e. an increase in density of woody plants often unpalatable to domestic livestock) is a serious problem in many savannas and threatens the livelihood of manyExpand
Soil quality gradients around water-points under different management systems in a semi-arid savanna, South Africa
Abstract Over 70% of South Africa is too arid for crop farming and is used for either commercial livestock ranching, communal livestock ranching, or game ranching. The inherently different managementExpand
Land degradation is not a necessary outcome of communal pastoralism in arid Namibia
Abstract In Otjimbingwe, a region of arid south-central Namibia, human population densities are high and these communal pastoralists own large numbers of livestock. Such situations are commonlyExpand
Evolution of plant defenses in nonindigenous environments.
The major evolutionary hypotheses predicting defense expression in plants, the hypotheses explaining defense evolution of exotic species, and the importance of geographic variation in ecological interactions to defense evolution are examined are examined. Expand
Direct and indirect effects of a predatory backswimmer (Notonecta maculata) on community structure of desert temporary pools
The negative association between the predator and Culiseta is attributed to local prey extinctions caused by Notonecta in individual pools, which is apparently more prone to predation than the vegetation‐dwelling Culex and Anopheles. Expand
Additions to, and a review of, the Miocene shark and ray fauna of Malta
Bulk sampling sediments and surface picking have increased the number of fossil sharks and rays from the Miocene of the Maltese Islands by 10 species and confirmed another. These are: SphyrnaExpand