Orders of magnitude increase in soil erosion associated with land use change from native to cultivated vegetation in a Brazilian savannah environment

Autor(es)

Oliveira, Paulo Tarso S. ^{[1, 2]} ; Nearing, Mark A. ^[2] ; Wendland, Edson ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Hydraul & Sanit Engn, BR-13560970 Sao Carlos, SP - Brazil

^[2] USDA ARS, Southwest Watershed Res Ctr, Tucson, AZ 85719 - USA

• Tipo de documento: Artigo Científico
• Fonte: EARTH SURFACE PROCESSES AND LANDFORMS; v. 40, n. 11, p. 1524-1532, SEP 15 2015.
• Citações Web of Science: 26

Resumo

The Brazilian savanna (cerrado) is a large and important economic and environmental region that is experiencing significant loss of its natural landscapes due to pressures of food and energy production, which in turn has caused large increases in soil erosion. However the magnitude of the soil erosion increases in this region is not well understood, in part because scientific studies of surface runoff and soil erosion are scarce or nonexistent in the cerrado as well as in other savannahs of the world. To understand the effects of deforestation we assessed natural rainfall-driven rates of runoff and soil erosion on an undisturbed tropical woodland classified as `cerrado sensu stricto denso' and bare soil. Results were evaluated and quantified in the context of the cover and management factor (C-factor) of the Universal Soil Loss Equation (USLE). Replicated data on precipitation, runoff, and soil loss on plots (5 x 20m) under undisturbed cerrado and bare soil were collected for 77 erosive storms that occurred over 3 years (2012 through 2014). C-factor was computed annually using values of rainfall erosivity and soil loss rate. We found an average runoff coefficient of similar to 20% for the plots under bare soil and less than 1% under undisturbed cerrado. The mean annual soil losses in the plots under bare soil and cerrado were 12.4 t ha(-1) yr(-1) and 0.1 t ha(-1) yr(-1), respectively. The erosivity-weighted C-factor for the undisturbed cerrado was 0.013. Surface runoff, soil loss and C-factor were greatest in the summer and fall. Our results suggest that shifts in land use from the native to cultivated vegetation result in orders of magnitude increases in soil loss rates. These results provide benchmark values that will be useful to evaluate past and future land use changes using soil erosion models and have significance for undisturbed savanna regions worldwide. Copyright (C) 2015 John Wiley \& Sons, Ltd. (AU)

• Processo FAPESP: 10/18788-5 - Balanço hídrico e erosão do solo em mata nativa do bioma Cerrado
• Beneficiário: Paulo Tarso Sanches de Oliveira
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 11/14273-3 - Balanço hídrico e erosão do solo em mata nativa do bioma cerrado
• Beneficiário: Luisa Fernanda Ribeiro Reis
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 12/03764-9 - Dinâmica do balanço hídrico e erosão do solo em área de cerrado
• Beneficiário: Paulo Tarso Sanches de Oliveira
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado