Land use in watersheds of the Venezuelan Andes: a comparative analysis

The influence of deforestation on tropical watersheds has received limited study. We compared seven catchments in the Venezuelan Andes to examine variation in the relative extent of forested versus disturbed land and the potential consequences of changing land use on river ecosystems. These watersheds formed a northeast (Rio Acarigua) to southwest (Rio Bumbun) transect and exhibited a gradient in readily. observable human settlement and disturbance. Overall, forest cover increased and agriculture and pasture land decreased from the Acarigua to the Bumbun. Human building density, and road density, showed a parallel trend. Catchments varied in intrinsic characteristics as well. Catchments to the northeast originated at lower elevations and bad wider flatter valleys in the lowest piedmont zone, compared with rivers to the southwest. All seven catchments bad broadly, similar forest cover oil approximately, 50-60%, within the lowest (200-800 in) elevation zone, but they exhibited a strong gradient in the amount of forested versus disturbed land in zones at 800-1400 in and 1400-2600 in. Although the number of buildings was greatest in the 200- to 800-m zone, building density, was greater in the 800- to 1400-m zone for the more disturbed catchments, possibly, reflecting the areas suitable for coffee production. Land-use change within these catchments is likely, to alter hydrology,, sediment transport, and habitat conditions within river systems, with adverse consequences for aquatic biodiversity.