Ecohydrological function of vegetation patches in semi-arid shrublands of central Mexico

Vegetation patterns in arid and semi-arid regions create source-sink systems with vegetated patches capturing the resources produced by inter-patches. Patches and inter-patches are the fundamental hydrological units, and their properties can be scaled up to describe ecohydrological functioning at the hillslope or catchment levels. The objective was to compare ecohydrological properties at the patch level in relation to ground cover and at the vegetation type level using landscape function analysis (LFA). Runoff and sediment production were measured in vegetation types of rosetophilous desert shrubland, microphyllous desert shrubland, and crassicaulescent shrubland. Inter-patches (cover = 12.54% +/- 2.35% SE) had the highest runoff rates and sediment production, while medium coverage patches (cover = 43.68% +/- 2.37% SE) and dense cover patches (cover = 83.56% +/- 2.48% SE) produced less runoff and sediments. Runoff, sediments and landscape organization were similar between vegetation types. High litter and stone fragment cover and low soil bulk density were associated with low runoff and sediment production. The LFA infiltration and stability indices explained 10 and 19% of the variability of infiltration and sediment production, respectively. Our results show that vegetation types function similarly, but the hydrological and erosional responses of patches and inter-patches are fundamental to supporting ecohydrologically-based management and restoration plans.