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Effects of human-induced land degradation on water and carbon fluxes in two different Brazilian dryland soil covers.
de Oliveira, Michele L; Dos Santos, Carlos A C; de Oliveira, Gabriel; Perez-Marin, Aldrin M; Santos, Celso A G.
Afiliação
  • de Oliveira ML; Graduate Program in Engineering and Natural Resources Management, Federal University of Campina Grande, Campina Grande, Paraíba 58109-970, Brazil.
  • Dos Santos CAC; Graduate Program in Engineering and Natural Resources Management, Federal University of Campina Grande, Campina Grande, Paraíba 58109-970, Brazil; Academic Unit of Atmospheric Sciences, Federal University of Campina Grande, Campina Grande, Paraíba 58109-970, Brazil. Electronic address: carlos.santos
  • de Oliveira G; Department of Earth Sciences, University of South Alabama, Mobile, AL 36688, USA.
  • Perez-Marin AM; National Institute of Semi-Arid, Campina Grande, Paraíba 58434-700, Brazil.
  • Santos CAG; Department of Civil and Environmental Engineering, Federal University of Paraíba, Paraíba, João Pessoa 58051-900, Brazil.
Sci Total Environ ; 792: 148458, 2021 Oct 20.
Article em En | MEDLINE | ID: mdl-34465045
The Brazilian semiarid region presents a physical water scarcity and high seasonal and interannual irregularities of precipitation, known as a region with periodic droughts. This region is mainly covered by the Caatinga biome, recognized as a Seasonally Dry Tropical Forest (SDTF). Soil water availability directly impacts the ecosystem's functioning, characterized by low fertility and sparse vegetation cover during the dry season, making it a fragile ecosystem vulnerable to climatic variations. Additionally, this region has been suffering from several issues due to human activities over the centuries, which has resulted in extensive areas being severely degraded, which aggravates the impacts from climatic variations and the susceptibility to desertification. Thus, studying the soil-plant-atmosphere continuum in this region can help better understand the seasonal and annual behavior of the water and carbon fluxes. This study investigated the dynamics of water and carbon fluxes during four years (2013-2016) by using eddy covariance (EC) measurements within two areas of Caatinga (dense Caatinga (DC) and sparse Caatinga (SC)) that suffered anthropic pressures. The two study areas showed similar behavior in relation to physical parameters (air temperature, incoming radiation, vapor pressure deficit, and relative humidity), except for soil temperature. The SC area presented a surface temperature of 3 °C higher than the DC, related to their vegetation cover differences. The SC area had higher annual evapotranspiration, representing 74% of the precipitation for the DC area and 90% for the SC area. The two areas acted as a carbon sink during the study period, with the SC area showing a lower CO2 absorption capacity. On average, the DC area absorbs 2.5 times more carbon than the SC area, indicating that Caatinga deforestation affects evaporative fluxes, reducing atmospheric carbon fixation and influencing the ability to mitigate the effects of increased greenhouse gas concentrations in the atmosphere.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Solo / Ecossistema Limite: Humans País/Região como assunto: America do sul / Brasil Idioma: En Revista: Sci Total Environ Ano de publicação: 2021 Tipo de documento: Article País de afiliação: Brasil País de publicação: Holanda

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Solo / Ecossistema Limite: Humans País/Região como assunto: America do sul / Brasil Idioma: En Revista: Sci Total Environ Ano de publicação: 2021 Tipo de documento: Article País de afiliação: Brasil País de publicação: Holanda