Mapping land degradation in the Gilbués region, northeastern Brazil, using Landsat TM images

Almeida-Filho, R.; Carvalho, Carolina Monteiro de

doi:10.1080/01431160903260957

Cited by 18 publications

(9 citation statements)

References 3 publications

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“…A return of woody vegetation in the Brazilian Caatinga region caused by the increases in rainfall and decrease in the area under cultivation during 2001-2009 was reported by Redo et al (2013), which may explain the strongly positive VOD wood trends in our analysis in northeast part of Brazil. Contrastingly, decreasing VOD wood trends in the south of Brazil indicating a loss of woody vegetation are likely to be caused by the highly degraded soil conditions in this region (Almeida-Filho & Carvalho, 2010).…”

Section: Interpretation Of Changes In Subcontinental Hot Spot Regionsmentioning

confidence: 83%

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Mapping gains and losses in woody vegetation across global tropical drylands

Tian

Brandt

Liu

et al. 2016

Global Change Biology

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Woody vegetation in global tropical drylands is of significant importance for both the interannual variability of the carbon cycle and local livelihoods. Satellite observations over the past decades provide a unique way to assess the vegetation long-term dynamics across biomes worldwide. Yet, the actual changes in the woody vegetation are always hidden by interannual fluctuations of the leaf density, because the most widely used remote sensing data are primarily related to the photosynthetically active vegetation components. Here, we quantify the temporal trends of the nonphotosynthetic woody components (i.e., stems and branches) in global tropical drylands during 2000-2012 using the vegetation optical depth (VOD), retrieved from passive microwave observations. This is achieved by a novel method focusing on the dry season period to minimize the influence of herbaceous vegetation and using MODerate resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data to remove the interannual fluctuations of the woody leaf component. We revealed significant trends (P < 0.05) in the woody component (VOD ) in 35% of the areas characterized by a nonsignificant trend in the leaf component (VOD modeled from NDVI), indicating pronounced gradual growth/decline in woody vegetation not captured by traditional assessments. The method is validated using a unique record of ground measurements from the semiarid Sahel and shows a strong agreement between changes in VOD and changes in ground observed woody cover (r = 0.78). Reliability of the obtained woody component trends is also supported by a review of relevant literatures for eight hot spot regions of change. The proposed approach is expected to contribute to an improved assessment of, for example, changes in dryland carbon pools.

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Section: Interpretation Of Changes In Subcontinental Hot Spot Regionsmentioning

confidence: 83%

“…(), which may explain the strongly positive VOD wood trends in our analysis in northeast part of Brazil. Contrastingly, decreasing VOD wood trends in the south of Brazil indicating a loss of woody vegetation are likely to be caused by the highly degraded soil conditions in this region (Almeida‐Filho & Carvalho, ).…”

Section: Discussionmentioning

confidence: 99%

Mapping gains and losses in woody vegetation across global tropical drylands

Tian

Brandt

Liu

et al. 2016

Global Change Biology

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“…Land degradation causes the reduction of biological productivity and affects the environmental, social and economic sustainability (Nunes et al, 2012). Especially, in the semi-arid region of Northeast Brazil, slash-and-burn practices combined with diamond-mining activities caused land degradation (Almeida-Filho and Carvalho, 2010). In addition, in this region, high temperatures and evapotranspiration associated with a short rainy period with high precipitation and fragile soils intensify the effects of anthropogenic land degradation.…”

Section: Introductionmentioning

confidence: 99%

Soil microbial properties and temporal stability in degraded and restored lands of Northeast Brazil

Araújo

Cesarz

Leite

et al. 2013

Soil Biology and Biochemistry

117

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Human activities, such as land use change, cause severe land degradation in many ecosystems around the globe with potential impacts on soil processes. Restoration practices aim at reverting such impacts and reconstituting the biotic composition and functioning of an ecosystem to its initial condition. The aim of this study was to monitor soil microbial properties in degraded lands in Northeast Brazil and to compare those with land under restoration. Soil samplings were conducted in 2009, 2010 and 2011 in two different seasons (wet and dry season) at sites differing in degradation status: native vegetation (NAT), moderately degraded land (MDL), highly degraded land (HDL), and land under restoration for four years (RES). Soil microbial properties showed pronounced fluctuations between seasons with higher levels of functioning in the wet than in the dry season. Soil microbial biomass and enzymes had significantly higher values under native vegetation than in degraded land, while restored land mostly corresponded to native vegetation. Soil microbial biomass, respiratory quotient and enzyme activities were more strongly affected by land degradation than soil chemical properties. Soil microbial properties varied more between seasons and years in highly degraded land than under native vegetation suggesting a buffering effect of the native vegetation on soil microbial processes. However, land degradation effects on soil microbial properties were significant in both seasons. Moreover, our results indicate that the land restoration practice applied here shifted soil microbial community composition as indicated by soil microbial stoichiometry. Our results indicate that land degradation strongly deteriorates soil microbial properties and their stability in time, but that land restoration practices likely are successful in promoting the recovery of some soil microbial functions, even after only four years. However, shifts in soil microbial community composition in restored lands may have significant feedback effects on element cycles.

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“…Approximately 23% of all arable land of the planet is being affected by land degradation, and, at the end of the last century, approximately 910 Mha were under moderate to extreme degradation (Oldeman, 1994). In Brazil, slashand-burn practices combined with diamond-mining activities have caused land degradation (Almeida-Filho & Carvalho, 2010;Thomaz & Luiz, 2012;Souza Braz et al, 2013). In addition, high temperatures and evapotranspiration associated with a short rainy period with high precipitation in this region and fragile soils may intensify the effects of anthropogenic land degradation.…”

Section: Introductionmentioning

confidence: 99%

Soil Surface‐Active Fauna in Degraded and Restored Lands of Northeast Brazil

et al. 2013

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Land degradation reducing vegetation cover may affect the soil surface-active fauna because both aboveground and belowground invertebrates depend on complex plant communities. In this study, we evaluated the effect of land degradation and restoration on soil fauna in northeast Brazil. Sites differed in degradation status: native vegetation, moderately degraded land, highly degraded land, and land under restoration for 4 years. Araneae and Coleoptera densities were significantly higher in natural vegetation and restored land (8 ± 4 ind./trap and 41 ± 21 ind./trap, respectively) than in degraded lands (À73% and À81%, respectively). The density of Formicidae was significantly higher in natural vegetation (206 ± 181 ind./trap) than in highly degraded land (32 ± 24 ind./trap), while restored land (51 ± 10 ind./trap) and moderately degraded land (37 ± 14 ind./trap) did not differ significantly from the other degradation levels. The density of Orthoptera did not follow the aforementioned patterns, while invertebrate groups mostly had highest densities in natural land and restored land. Linear regressions showed a strong negative relation between faunal density and soil bulk density, and a positive relation with soil organic matter due to an increase in plant cover. Our results indicate that land degradation simplifies soil surface-active invertebrate communities with pronounced decreases in the density of Araneae, Coleoptera, and Formicidae, but that land restoration practices may recover the density of soil fauna even after only 4 years. Araneae, Coleoptera, and Formicidae respond sensitively to land degradation and restoration practice and are suggested as indicator groups for restoration success.

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Mapping land degradation in the Gilbués region, northeastern Brazil, using Landsat TM images

Cited by 18 publications

References 3 publications

Mapping gains and losses in woody vegetation across global tropical drylands

Mapping gains and losses in woody vegetation across global tropical drylands

Soil microbial properties and temporal stability in degraded and restored lands of Northeast Brazil

Soil Surface‐Active Fauna in Degraded and Restored Lands of Northeast Brazil

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