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de Oliveira ML, Dos Santos CAC, de Oliveira G, Silva MT, da Silva BB, Cunha JEDBL, Ruhoff A, Santos CAG. Remote sensing-based assessment of land degradation and drought impacts over terrestrial ecosystems in Northeastern Brazil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 835:155490. [PMID: 35476950 DOI: 10.1016/j.scitotenv.2022.155490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 04/19/2022] [Accepted: 04/20/2022] [Indexed: 06/14/2023]
Abstract
The spatio-temporal assessment of water and carbon fluxes in Brazil's Northeast region (NEB) allows for a better understanding of these surface flux patterns in areas with different vegetation physiognomies. The NEB is divided into four biomes: Amazon, Cerrado, Caatinga, and Atlantic Forest. Land degradation is a growing problem, particularly in susceptible areas of the Caatinga biome, such as the seasonally dry tropical forest. Furthermore, this region has experienced climatic impacts, such as severe droughts. Due to increasing human pressure, the Caatinga's natural land cover undergoes drastic changes, making it a region particularly vulnerable to desertification. In this study, the Moderate Resolution Imaging Spectroradiometer (MODIS) estimates of evapotranspiration (ET) and gross primary production (GPP) were validated in two contrasting areas, dense Caatinga and sparse Caatinga, using eddy covariance (EC) data and then investigated their behavior over 21 years (2000-2021) for the NEB. MODIS products explained around 60% of the variations in ET and GPP, showing higher accuracy in dense Caatinga, while areas of sparse Caatinga presented the lowest GPP, indicating that land degradation has reduced the photosynthetic activity of the vegetation in this area. Based on the analysis of ET and GPP over 21 years, we observed a greater dependence of the sparse Caatinga on climate variability, demonstrating a stronger resilience of dense Caatinga to climate effects. In comparison with the other biomes of the NEB region, we found lower rates of ET and GPP in the Caatinga biome, with averages similar to the Sparse Caatinga. In comparison with the other biomes in the NEB region, we found the lowest averages of ET and GPP in the Caatinga biome, similar to values found in the sparse Caatinga. In forest areas, similar to the monitored DC, they allowed the Caatinga to behave closer to the other biomes present in the region.
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Affiliation(s)
- Michele L de Oliveira
- Graduate Program in Engineering and Natural Resources Management, Federal University of Campina Grande, Campina Grande, Paraíba 58109-970, Brazil.
| | - Carlos A C Dos Santos
- Graduate Program in Engineering and Natural Resources Management, Federal University of Campina Grande, Campina Grande, Paraíba 58109-970, Brazil; Graduate Program in Meteorology, Academic Unity of Atmospheric Sciences, Federal University of Campina Grande, Campina Grande, Paraíba 58109-970, Brazil.
| | - Gabriel de Oliveira
- Department of Earth Sciences, University of South Alabama, Mobile, AL 36688, USA.
| | - Madson T Silva
- Graduate Program in Engineering and Natural Resources Management, Federal University of Campina Grande, Campina Grande, Paraíba 58109-970, Brazil; Graduate Program in Meteorology, Academic Unity of Atmospheric Sciences, Federal University of Campina Grande, Campina Grande, Paraíba 58109-970, Brazil.
| | - Bernardo B da Silva
- Graduate Program in Meteorology, Academic Unity of Atmospheric Sciences, Federal University of Campina Grande, Campina Grande, Paraíba 58109-970, Brazil.
| | - John E de B L Cunha
- Graduate Program in Meteorology, Academic Unity of Atmospheric Sciences, Federal University of Campina Grande, Campina Grande, Paraíba 58109-970, Brazil.
| | - Anderson Ruhoff
- Instituto de Pesquisas Hidráulicas, Universidade Federal Rio Grande do Sul, Porto Alegre, RS 91501-970, Brazil.
| | - Celso A G Santos
- Department of Civil and Environmental Engineering, Federal University of Paraíba, Paraíba, João Pessoa 58051-900, Brazil.
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