Saturated Hydraulic Conductivity and Land Use Change, New Insights to the Payments for Ecosystem Services Programs: a Case Study from a Tropical Montane Cloud Forest Watershed in Eastern Central Mexico

Abstract

Water infiltration into soil is a complex process that in field conditions varies for every precipitation event (Wit, 2001) due mainly to its dependence of antecedent soil moisture (Cerda, 1995; Lassen & Lull, 1951). Some authors use saturated hydraulic conductivity (Ks) as a descriptor of the infiltration process (Wit, 2001; Ziegler, et al., 2004). This hydrophysical variable allows field based comparison between sites with different initial moisture contents and soil characteristics. Several researches report differences in infiltration and Ks, associated to vegetation patches (Cerda & Doerr, 2005), land use change patterns (Buytaert, et al., 2005; Tobon, et al., 2004; Ziegler, et al., 2004) and vegetation recovery (Li & Shao, 2006; Zimmermann & Elsenbeer, 2008). This trend has been reported in many different ecosystems and vegetation types ranging from tropical rain forests (Zimmermann & Elsenbeer, 2008) to semiarid and Mediterranean shrublands (Cerda & Doerr, 2005; Li & Shao, 2006). Differences can be marginal or up to several orders of magnitude (Li & Shao, 2006). This allowed the possibility of using land use and plant cover as an indicative variable of the infiltration process. Payment for ecosystem services (PES) schemes include in most cases a “consumer” that pays the “provider” for maintaining the ecosystem functions that generate the ecosystem services in question. Perhaps, two of the most common examples of payment for ecosystem services are the carbon sequestration programs (Ordonez, et al., 2008) and the hydrologic service initiatives (Naranjo & Murgueitio, 2006). In Mexico, the Federal Government has recently developed a strategy of payment for ecosystem services (PES) which encompass biodiversity, carbon sequestration and hydrologic ecosystem services. The Mexican program in 2008 had the largest budget worldwide for such an initiative (60 millions US dollars) (CONAFOR, 2008). While an important step in the incorporation of economics to conservation, some authors pointed out