Effects of land use/cover and landform on upper soil physical properties in the highlands of Veracruz, Mexico
Abstract
Within tropical montane catchments, spatial patterns of soil properties often exhibit the direct influence of topography. Contemporary mosaics of land use/cover impart additional variability to these already complex landscapes. Deforestation has been shown to degrade many of the soil physical characteristics that regulate ecohydrologic fluxes. Reestablishment of forest cover (naturally or via reforestation) may restore these properties; however, the evidence remains inconclusive and site-specific. In five first-order catchments in central Veracruz, Mexico, we assessed how land use/cover affected soil saturated hydraulic conductivity (Ksat) and porosity (pt) and how landform mediated those relationships. The selected catchments differed in terms of dominant land-cover type and/or land-use intensity (i.e., young, intermediate, and mature cloud forests and low- and high-intensity coffee agroforests). We conducted intensive surveys of ground cover and soil surface properties and soil penetration resistance to 30 cm depth, using the topographic position index to stratify 24 sampling points per catchment. At six of those points, we also measured Ksat and other standard physical properties at the soil surface. Our results showed greatest surface Ksat and pt under forest cover on loamy ridges and backslopes, with lower values on clayey toeslopes. Under coffee agroforest, upland positions exhibited lower values of surface Ksat and pt, such that the topographic contrast in soil properties was diminished. These preliminary results suggest that, in catchments where soil permeability increases from lowlands to uplands, the beneficial effects of regenerating or remnant forest cover on soil physical properties may be disproportionately high on slopes and ridges.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.H33G1632L
- Keywords:
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- 1632 Land cover change;
- GLOBAL CHANGEDE: 1807 Climate impacts;
- HYDROLOGYDE: 1813 Eco-hydrology;
- HYDROLOGYDE: 1884 Water supply;
- HYDROLOGY