HR: 14:45h
AN: B43A-04    [Abstracts]
TI: Land use Controls on Water Quality and Aquatic Ecosystems in the Andean Amazon, Peru
AU: * Waggoner, L A
EM: lwaggoner@montana.edu
AF: Big Sky Carbon Sequestration Partnership: Montana State University, PO BOX 172460, Bozeman, MT 59715, United States
AU: McClain, M E
EM: michael.mcclain@fiu.edu
AF: Global Water for Sustainability: Florida International University, Department of Environmental Studies, 11200 SW 8th St, Miami, FL 33199, United States
AB: Agro-pastoral systems are replacing many of the tropical forests in the world, and much of this deforestation occurs in watersheds where people's livelihoods rely directly on water and aquatic resources in local streams and rivers. We examined relationships between land use and aquatic ecosystems in 34 catchments exhibiting a gradient of land use disturbance and human settlement in the Andean Amazon of Peru. Our research objectives were to 1) classify and characterize watershed land use and physical properties using remotely sensed data, 2) characterize the physical, biological and chemical conditions of streams 3) examine relationships between land use and water quality parameters at 3 scales: watershed, riparian and reach habitat and 4) translate research findings into management strategies that minimize disturbance and maximize ecosystem services. Primary forest was the dominant cover (68%) across the catchments, and the remaining study area was composed of: mixed forest (11.5%), grassland (10.75%) cropland (9.17%) and bare rock (0.02%). Among watersheds, forest cover ranged from 14% to 100%, mixed forest ranged from 0% to 26%, grassland ranged from 0% to 45% and cropland ranged from 0% to 26%. Physical habitat index scores ranged from 12.80 (very impaired) to 29.50 (reference conditions). Although nitrogen, phosphorous, dissolved organic carbon (DOC), pH, electric conductivity, and dissolved oxygen (DO), varied across sites, total concentrations remained within acceptable levels. Simpson's diversity and Family Biotic Index (FBI) were calculated for macroinvertebrates collected at each site; Simpson's diversity ranged from 0.24 to 0.95 and FBI ranged from 1.97 (excellent) to 7.49 (fairly poor). Forest cover at the watershed scale was the best explanatory variable and was positively correlated with inorganic phosphate (0.50), DO (0.90) and Simpson's diversity (0.46) and negatively correlated with organic phosphate (- 0.64), DOC (-0.75), water temperature (-0.89), electric conductivity (-0.62) and the FBI (-0.82). Of the managed land uses, riparian grassland was found to have the most significant negative impact on water quality and biologic communities. Our results demonstrate the benefits of maintaining forest cover and promoting sustainable agriculture over ranching in riparian zones.
DE: 0483 Riparian systems (0744, 1856)
DE: 0496 Water quality
DE: 1632 Land cover change
DE: 1813 Eco-hydrology
DE: 1879 Watershed
SC: Biogeosciences [B]
MN: 2007 Joint Assembly