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Conversion from forests to pastures in the Colombian Amazon leads to differences in dead wood dynamics depending on land management practices.
Navarrete, Diego; Sitch, Stephen; Aragão, Luiz E O C; Pedroni, Lucio; Duque, Alvaro.
Afiliação
  • Navarrete D; Department of Geography, College of Life and Environmental Sciences, University of Exeter, Rennes Drive, Exeter EX4 4RJ, UK. Electronic address: danavarretee@gmail.com.
  • Sitch S; Department of Geography, College of Life and Environmental Sciences, University of Exeter, Rennes Drive, Exeter EX4 4RJ, UK.
  • Aragão LEOC; Department of Geography, College of Life and Environmental Sciences, University of Exeter, Rennes Drive, Exeter EX4 4RJ, UK; Remote Sensing Division, National Institute for Space Research, Av. dos Astronautas, 1758, 12227-010, São José dos Campos, São Paulo, Brazil.
  • Pedroni L; Carbon Decisions International, Residencial la Castilla, de la primera entrada, 6ta casa a mano derecha, Paraíso de Cartago, Costa Rica.
  • Duque A; Departamento de Ciencias Forestales, Universidad Nacional de Colombia - Sede Medellín, Medellín, Colombia.
J Environ Manage ; 171: 42-51, 2016 Apr 15.
Article em En | MEDLINE | ID: mdl-26874613
Dead wood, composed of coarse standing and fallen woody debris (CWD), is an important carbon (C) pool in tropical forests and its accounting is needed to reduce uncertainties within the strategies to mitigate climate change by reducing deforestation and forest degradation (REDD+). To date, information on CWD stocks in tropical forests is scarce and effects of land-cover conversion and land management practices on CWD dynamics remain largely unexplored. Here we present estimates on CWD stocks in primary forests in the Colombian Amazon and their dynamics along 20 years of forest-to-pasture conversion in two sub-regions with different management practices during pasture establishment: high-grazing intensity (HG) and low-grazing intensity (LG) sub-regions. Two 20-year-old chronosequences describing the forest-to-pasture conversion were identified in both sub-regions. The line-intersect and the plot-based methods were used to estimate fallen and standing CWD stocks, respectively. Total necromass in primary forests was similar between both sub-regions (35.6 ± 5.8 Mg ha(-1) in HG and 37.0 ± 7.4 Mg ha(-1) in LG). An increase of ∼124% in CWD stocks followed by a reduction to values close to those at the intact forests were registered after slash-and-burn practice was implemented in both sub-regions during the first two years of forest-to-pasture conversion. Implementation of machinery after using fire in HG pastures led to a reduction of 82% in CWD stocks during the second and fifth years of pasture establishment, compared to a decrease of 41% during the same period in LG where mechanization is not implemented. Finally, average necromass 20 years after forest-to-pasture conversion decreased to 3.5 ± 1.4 Mg ha(-1) in HG and 9.3 ± 3.5 Mg ha(-1) in LG, representing a total reduction of between 90% and 75% in each sub-region, respectively. These results highlight the importance of low-grazing intensity management practices during ranching activities in the Colombian Amazon to reduce C emissions associated with land-cover change from forest to pasture.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Madeira / Florestas / Agricultura País/Região como assunto: America do sul / Colombia Idioma: En Revista: J Environ Manage Ano de publicação: 2016 Tipo de documento: Article País de publicação: Reino Unido

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Madeira / Florestas / Agricultura País/Região como assunto: America do sul / Colombia Idioma: En Revista: J Environ Manage Ano de publicação: 2016 Tipo de documento: Article País de publicação: Reino Unido