First approximation of the effects of rainfall on the ecology and energetics of a Namib Desert dune ecosystem

Spiders, spinifex, rainfall and fire: Long-term changes in an arid spider assemblage

“…In the hyperarid Namib Desert, for example, biomass of carnivorous arthropods increased only 34% after rains, compared to herbivores (110%) and omnivores (1534%) (Seely and Louw, 1980). However, increases in spider abundance of over 100% in favourable years has been found in more recent studies of less extreme arid regions (this study and that of Polis et al, 1998, on islands in the Gulf of California).…”

Changes in water relations for Acacia ancistrocarpa on natural and mine-rehabilitation sites in response to an experimental wetting pulse in the Great Sandy Desert

“…Short pulses of summer rainfall can be used only by plant species that maintain active shallow root systems (Ehleringer et al 1991, Lin et al 1996, Schwinning et al 2003. This is particularly important for fine-textured soils as water is retained in shallow soil layers, and due to strong capillary forces, is readily evaporated from the surface (Seely and Louw 1980;Orshan 1986;Brown and Archer 1990). By contrast, sandy soils permit rapid infiltration of water to deeper soil layers and relatively weak capillary forces limit evaporative extraction from the soil surface, so a greater proportion of rainfall penetrates to depth; a process termed the 'inverse texture effect' (Noy-Meir 1973;Sala et al 1988;.…”

Patterns of occurrence of reptiles across a sand dune landscape

“…Temporal effects can be acute in extremely arid deserts since variation in annual precipitation increases as mean annual rainfall decreases (Noy-Meir, 1973;Bell, 1979;MacMahon, 1979). In arid ecosystems, highly variable and unpredictable precipitation often becomes the driver of biological processes (Noy-Meir, 1973;Seely and Louw, 1980;Abts, 1987;Castañ eda-Gayá n et al, 2003;Barrows, 2006). Within arid landscapes, sand dunes provide a spatially heterogeneous, temporally dynamic and biologically rich landscape given their variable levels of vegetation cover, dune stability and sand compaction (Seely and Louw, 1980;Barrows, 2000;Barrows and Allen, 2007).…”

“…In arid ecosystems, highly variable and unpredictable precipitation often becomes the driver of biological processes (Noy-Meir, 1973;Seely and Louw, 1980;Abts, 1987;Castañ eda-Gayá n et al, 2003;Barrows, 2006). Within arid landscapes, sand dunes provide a spatially heterogeneous, temporally dynamic and biologically rich landscape given their variable levels of vegetation cover, dune stability and sand compaction (Seely and Louw, 1980;Barrows, 2000;Barrows and Allen, 2007). Our objectives were to model the occurrence of reptiles occurring across an aeolian sand landscape, and to identify environmental variables that correlate with those patterns.…”