Land-use-driven stream warming in southeastern Amazonia Journal Article

Authors: Macedo, M. N.; Coe, M. T.; DeFries, R.; Uriarte, M.; Brando, P. M.; Neill, C.; Walker, W. S.
Article Title: Land-use-driven stream warming in southeastern Amazonia
Abstract: Large-scale cattle and crop production are the primary drivers of deforestation in the Amazon today. Such land-use changes can degrade stream ecosystems by reducing connectivity, changing light and nutrient inputs, and altering the quantity and quality of streamwater. This study integrates field data from 12 catchments with satellite-derived information for the 176,000 km(2) upper Xingu watershed (Mato Grosso, Brazil). We quantify recent land-use transitions and evaluate the influence of land management on streamwater temperature, an important determinant of habitat quality in small streams. By 2010, over 40 per cent of catchments outside protected areas were dominated (greater than 60% of area) by agriculture, with an estimated 10,000 impoundments in the upper Xingu. Streams in pasture and soya bean watersheds were significantly warmer than those in forested watersheds, with average daily maxima over 4 degrees C higher in pasture and 3 degrees C higher in soya bean. The upstream density of impoundments and riparian forest cover accounted for 43 per cent of the variation in temperature. Scaling up, our model suggests that management practices associated with recent agricultural expansion may have already increased headwater stream temperatures across the Xingu. Although increased temperatures could negatively impact stream biota, conserving or restoring riparian buffers could reduce predicted warming by as much as fivefold.
Keywords: WATER; TEMPERATURE; rivers; ECOSYSTEM; Brazil; RAIN; Seasons; Environmental Monitoring/methods; Conservation of Natural Resources/methods; Agriculture/methods; Remote Sensing Technology; Soybeans
Journal Title: Philosophical Transactions of the Royal Society of London Series B-Biological Sciences
Volume: 368
Issue: 1619
ISSN: 0962-8436
Publisher: Royal Society, The  
Publication Place: England
Date Published: 2013
Start Page: 20120153
Language: eng
Notes: JID: 7503623; 059QF0KO0R (Water); OID: NLM: PMC3638424 [Available on 06/05/14]; PMCR: 2014/06/05 00:00; 2013 [ppublish]; epublish