Analyzing ecological restoration strategies for water and soil conservation

PLOS ONE, Nov 2019

The choice of areas for nature conservation involves the attempt to maximize the benefits, whether by carrying out an economic activity or by the provision of Ecosystem Services. Studies are needed to improve the understanding of the effect of the extent and position along the watershed of restored areas on soil and water conservation. This study aimed to understand how different restoration strategies might reflect in soil conservation and sediment retention. Using InVEST tool, sediment transport was simulated in a small 12 km2 watershed (Posses River, in Southeast Brazil), where one of first Brazilian Payment for Ecosystem Services (PES) projects is being carried out, comparing different hypothetical restoration strategies. With 25% of restoration, sediment export decreased by 78% for riparian restoration, and 27% for the steepest slopes restoration. On the other hand, the decrease in soil loss was lower for riparian restoration, with a 16% decrease, while the steepest slopes restoration reduced it by 21%. This mismatch between the reduction of sediment export and soil loss was explained by the fact that forest not only reduces soil loss locally but also traps sediment arriving from the upper parts of the watershed. While the first mechanism is important to provide soil stability, decreasing the risk of landslip, and to maintain agricultural productivity, the second can improve water quality and decrease the risk of silting, with positive effects on the water reservoirs at the outlet of the watershed. This suggests that Riparian and the Steepest Slopes restoration strategies are complementary in the sense of preventing sediments from reaching the water bodies as well as protecting them at their origin (with the reduction of erosion), so it will be advisable to consider the two types of restoration.

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Analyzing ecological restoration strategies for water and soil conservation

February Analyzing ecological restoration strategies for water and soil conservation Sandra Isay Saad 0 1 Jonathan Mota da Silva 1 Marx Leandro Naves Silva 1 João Luis Bittencourt Guimarães 1 Wilson Cabral Sousa Ju nior 1 Ricardo de Oliveira Figueiredo 1 Humberto Ribeiro da Rocha 1 0 Graduate Program of Environmental Science, Institute of Energy and Environment, University of São Paulo , São Paulo , Brazil , 2 Department of Atmospheric and Climatic Sciences, Federal University of Rio Grande do Norte, Natal, Brazil, 3 Departamento de Ciência do Solo, Universidade Federal de Lavras , Lavras, Brazil, 4 Aquaflora Meio Ambiente, Curitiba, Brazil , 5 Department of Water Resources and Environment, Aeronautics Institute of Technology , São Jose dos Campos, Brazil, 6 Embrapa Environment , Brazilian Agricultural Research Coorporation, JaguariuÂna, Brazil, 7 Department of Atmospheric Science, Institute of Astronomy, Geophysics, and Atmospheric Sciences, University of São Paulo , São Paulo , Brazil 1 Editor: Julia A. Jones, Oregon State University , UNITED STATES The choice of areas for nature conservation involves the attempt to maximize the benefits, whether by carrying out an economic activity or by the provision of Ecosystem Services. Studies are needed to improve the understanding of the effect of the extent and position along the watershed of restored areas on soil and water conservation. This study aimed to understand how different restoration strategies might reflect in soil conservation and sediment retention. Using InVEST tool, sediment transport was simulated in a small 12 km2 watershed (Posses River, in Southeast Brazil), where one of first Brazilian Payment for Ecosystem Services (PES) projects is being carried out, comparing different hypothetical restoration strategies. With 25% of restoration, sediment export decreased by 78% for riparian restoration, and 27% for the steepest slopes restoration. On the other hand, the decrease in soil loss was lower for riparian restoration, with a 16% decrease, while the steepest slopes restoration reduced it by 21%. This mismatch between the reduction of sediment export and soil loss was explained by the fact that forest not only reduces soil loss locally but also traps sediment arriving from the upper parts of the watershed. While the first mechanism is important to provide soil stability, decreasing the risk of landslip, and to maintain agricultural productivity, the second can improve water quality and decrease the risk of silting, with positive effects on the water reservoirs at the outlet of the watershed. This suggests that Riparian and the Steepest Slopes restoration strategies are complementary in the sense of preventing sediments from reaching the water bodies as well as protecting them at their origin (with the reduction of erosion), so it will be advisable to consider the two types of restoration. - doctoral fellowship and the Project Fapesp ClimateWise "Climate-Smart Watershed Investments in the Montane Tropics of South America" (2015/50682-6). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This work was also supported by Fapesp ECOFOR "Biodiversity and Ecosystem Functioning in degraded and recovering Amazonian and Atlantic Forests" (2012/51872-5). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The author JLBG is affiliated with the commercial company Aquaflora Meio Ambiente. The funder provided support in the form of salaries for JLBG, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of this author are articulated in the `author contributions' section. Competing interests: JLBG is affiliated with the commercial company Aquaflora Meio Ambiente, which had no role in this study. There are no patents, products in development or marketed products to declare. This does not alter our adherence to all the PLOS ONE policies on sharing data and materials. Introduction While the conservation of natural resources in not valued in traditional economics [ 1 ], there is a growing perception of the strong human dependence on Ecosystem Services (ES) [ 2 ]. Attempts to avoid ecosystem degradation face great challenges: on one hand, most of policies to avoid deforestation have been inefficient [ 3 ], and, on the other, ecosystem restoration is costly, and funds are generally limited [ 4 ]. Around the world, billions of dollars have been spent on ecosystem restoration programs which have not always been successful [ 5,6 ]. In fact, there is a need to choose priority zones for nature conservation that consider both environmental and social-economic issues as conservation priorities are needed for planning and decision making [7]. When it comes to achieving the economic viability of Paym (...truncated)


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Sandra Isay Saad, Jonathan Mota da Silva, Marx Leandro Naves Silva, João Luis Bittencourt Guimarães, Wilson Cabral Sousa Júnior, Ricardo de Oliveira Figueiredo, Humberto Ribeiro da Rocha. Analyzing ecological restoration strategies for water and soil conservation, PLOS ONE, 2018, Volume 13, Issue 2, DOI: 10.1371/journal.pone.0192325