Soil and water components of banded vegetation patterns

摘要: Abstract Banded landscapes are comprised of alternating bands vegetation and bare ground aligned along the contours in arid semi-arid regions (50–750 mm rainfall), on very gentle uniform slopes (0.2–2%). Vegetated can be perpendicular to direction dominant wind, or more frequently slope. Under given climatic conditions, slope gradient is controlling factor type pattern (`spotted', `broadly' `typically' banded). For a gradient, mean annual rainfall determines contrast between vegetated phase, as well band length interband width:band width ratio. A typical transect through such two-phase mosaic includes dynamic succession surface crusts which generates run-off–run-on system. This favours capture limited water resources thus biomass production greater for banded patterns than spotted uniformly scattered vegetation. Moreover, act natural bench structures that greatly limit soil erosion. As suggested by modelling, equally derived from nearly areas dense patterns. Because have often been considered form degradation previous continuous cover, many attempts made foresters restore this initial cover reforestation interbands. However numerous failures interbands illustrate key role these components maintenance tiger bush ecosystem. resilient climate change human disturbances. The loss landscape patchiness due clearing either fuelwood ephemeral cropping induces rapid decline fertility infiltration potential. Long-term monitoring shows ratio adapts variations intrinsic zones. changes might also induce patterning, suggesting highly self-sustainable. ecological differences pioneer decaying edges bands, temporal/spatial crusts, other indices spatial distribution organic matter termite nests suggest upslope migration bands. Nevertheless field evidence shift remains scarce. Profound lessons learnt study terms ecosystems functions. When designing water-harvesting systems, restoring degraded land, should imitated optimize land degradation.