Islands of hydrologically enhanced biotic productivity in natural and managed arid ecosystems

The objective of this paper is to examine the spatial variability of islands of enhanced hydrologic activity and its application to remediation of degraded arid and semi-arid ecosystems. Factors causing high spatial variability of water in arid regions include precipitation, soil, physiography, and vegetation. Inherent heterogeneity of arid lands causes areas of runoff and run-on which lead to development of islands of hydrologically enhanced biotic productivity. These hydrologic islands are observed at the individual plant scale as well as in large area patterns of banded vegetation, playettes and playas, and beaded drainage networks where run-on and infiltration stimulate vegetation growth. To remediate degraded rangeland, it may be prudent to mimic nature by diverting water to target areas to create patterns similar to natural islands of hydrologically enhanced biotic productivity. Installation of structures such as water ponding dikes can promote changes to natural vegetation patterns at a landscape scale.