Climate change and thresholds of biome shifts in Amazonia

Salazar, Luis; Nobre, Carlos A.

doi:10.1029/2010gl043538

Cited by 56 publications

(49 citation statements)

References 39 publications

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“…It has been suggested that there may be thresholds or "tipping points" that should not be transgressed for the maintenance of the Amazonian tropical forests: 40% of area deforested, beyond which forest loss causes climate impacts that cause further forest loss (91); global warming of 3°C to 4°C may also lead to a similar tipping point (106,107). Although the existence of these tipping points still requires further research, interaction between climate change due to global warming and due to large-scale deforestation may make them more likely.…”

Section: Significancementioning

confidence: 99%

“…Controlled fire experiments carried out in the transition forests of northern Mato Grosso showed great incidence of lianas and tree mortality, supporting, according to the authors (71), the likelihood of "savannization" of parts of the Amazon. Depending on the scale, these changes could ultimately drive changes in the local climate, pushing the ecosystem toward a different forest−climate equilibrium state (159), that is, the one where most of the tropical forests in southern, southwestern, and southeastern Amazon are replaced by degraded savannas as predicted by models (91,106,158,160). Evidence that the relationship between degraded forest, regional climate change, and a change in the equilibrium would lead to a tipping point in the Amazon region is described as a medium-confidence likelihood (161), but is already being observed in the Xingu basin (71).…”

Section: Impacts Of Anthropogenic Drivers Of Change In the Amazonmentioning

confidence: 99%

“…The Amazon region has experienced a temperature increase of close to 1°C (51,73), mostly due to global warming. It is estimated that 3.5°C of global warming (that corresponds to about 4°C temperature increase in the Amazon) could disrupt the forest−climate equilibrium, leading to substantial loss of tropical forests (106,160,161). In addition, as mentioned above, there is some observational evidence of a lengthening of the dry season in southern−southeastern Amazon, and this is the most important driver of forest transitioning to savanna as claimed by the hypothesis of Amazon savannization (7) because the climate envelope for tropical forests requires a dry season (less than 100 mm·mo −1 ) no longer than 4 mo.…”

Section: Impacts Of Anthropogenic Drivers Of Change In the Amazonmentioning

confidence: 99%

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Land-use and climate change risks in the Amazon and the need of a novel sustainable development paradigm

Nobre

Sampaio

Borma

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

664

449

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For half a century, the process of economic integration of the Amazon has been based on intensive use of renewable and nonrenewable natural resources, which has brought significant basin-wide environmental alterations. The rural development in the Amazonia pushed the agricultural frontier swiftly, resulting in widespread land-cover change, but agriculture in the Amazon has been of low productivity and unsustainable. The loss of biodiversity and continued deforestation will lead to high risks of irreversible change of its tropical forests. It has been established by modeling studies that the Amazon may have two "tipping points," namely, temperature increase of 4°C or deforestation exceeding 40% of the forest area. If transgressed, large-scale "savannization" of mostly southern and eastern Amazon may take place. The region has warmed about 1°C over the last 60 y, and total deforestation is reaching 20% of the forested area. The recent significant reductions in deforestation-80% reduction in the Brazilian Amazon in the last decade-opens up opportunities for a novel sustainable development paradigm for the future of the Amazon. We argue for a new development paradigm-away from only attempting to reconcile maximizing conservation versus intensification of traditional agriculture and expansion of hydropower capacity-in which we research, develop, and scale a high-tech innovation approach that sees the Amazon as a global public good of biological assets that can enable the creation of innovative high-value products, services, and platforms through combining advanced digital, biological, and material technologies of the Fourth Industrial Revolution in progress.Amazon tropical forests | Amazon sustainability | Amazon land use | Amazon savannization | climate change impacts

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Section: Significancementioning

confidence: 99%

Section: Impacts Of Anthropogenic Drivers Of Change In the Amazonmentioning

confidence: 99%

Section: Impacts Of Anthropogenic Drivers Of Change In the Amazonmentioning

confidence: 99%

See 1 more Smart Citation

Land-use and climate change risks in the Amazon and the need of a novel sustainable development paradigm

Nobre

Sampaio

Borma

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

664

449

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show abstract

“…The authors highlighted that partial deforestation can lead to an increase in precipitation locally, whilst increasing deforestation can lead to drier conditions. In terms of future projections, Salazar, L.F. et al [23] performed simulations using a regional climate model from the Centro de Previsão de Tempo e Estudos Climáticos nested with the Potential Vegetation Model (CPTEC-PVM2.0) and different prescribed annual anomalies precipitation and temperature added to the observed climatology, and different levels of CO 2 fertilization effects under emission scenario A2. These simulations indicate that: (a) tropical forests might be replaced by seasonal forests or savanna over eastern Amazonia with temperature increases of 2-3 • C, when the CO 2 fertilization effect is not considered; (b) a decrease in precipitation greater than 30% may shift tropical forest to drier biomes in southeastern Amazonia.…”

Section: Introductionmentioning

confidence: 99%

Land Use Change over the Amazon Forest and Its Impact on the Local Climate

Llopart

Reboita

Coppola

et al. 2018

Water

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One of the most important anthropogenic influences on climate is land use change (LUC).In particular, the Amazon (AMZ) basin is a highly vulnerable area to climate change due to substantial modifications of the hydroclimatology of the region expected as a result of LUC. However, both the magnitude of these changes and the physical process underlying this scenario are still uncertain. This work aims to analyze the simulated Amazon deforestation and its impacts on local mean climate. We used the Common Land Model (CLM) version 4.5 coupled with the Regional Climate Model (RegCM4) over the Coordinated Regional Climate Downscaling Experiment (CORDEX) South America domain. We performed one simulation with the RegCM4 default land cover map (CTRL) and one simulation under a scenario of deforestation (LUC), i.e., replacing broadleaf evergreen trees with C 3 grass over the Amazon basin. Both simulations were driven by ERA Interim reanalysis from 1979 to 2009. The climate change signal due to AMZ deforestation was evaluated by comparing the climatology of CTRL with LUC. Concerning the temperature, the deforested areas are about 2 • C warmer compared to the CTRL experiment, which contributes to decrease the surface pressure. Higher air temperature is associated with a decrease of the latent heat flux and an increase of the sensible heat flux over the deforested areas. AMZ deforestation induces a dipole pattern response in the precipitation over the region: a reduction over the west (about 7.9%) and an increase over the east (about 8.3%). Analyzing the water balance in the atmospheric column over the AMZ basin, the results show that under the deforestation scenario the land surface processes play an important role and drive the precipitation in the western AMZ; on the other hand, on the east side, the large scale circulation drives the precipitation change signal. Dipole patterns over scenarios of deforestation in the Amazon was also found by other authors, but the precipitation decrease on the west side was never fully explained. Using budget equations, this work highlights the physical processes that control the climate in the Amazon basin under a deforestation scenario.

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“…On the other hand, trees have been colonizing a well-established, stable and highly diverse grass dominated ecosystem in the study site (Behling & Pillar, 2007), which is fundamentally different from what has been observed in boreal systems, where due to low or no resistance from resident vegetation, forest expansion occurs at much faster rates. In contrast to the above results predicting forest expansion over savanna, Salazar and Nobre (2010) assume that tropical forests might be replaced by seasonal forests or savanna over eastern Amazonia with temperature increases of 2-5 °C, when CO 2 fertilization effect is not or partially considered. A precipitation decrease greater than 30% would also trigger the shift from tropical forest to drier biomes, such as savanna and shrubland in southeastern Amazonia.…”

Section: Savannization and Forest Encroachmentmentioning

confidence: 92%

Impacts of Climate Change on Vegetation Distribution No. 2 - Climate Change Induced Vegetation Shifts in the New World

Hufnágel¹,

Garamvölgyi²

2014

Appl Ecol Env Res

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Abstract. After giving an overview of climate change induced vegetation shifts in the Palearctic region in our previous paper, in this article we review literature available in Web of Science on North and South America. We study different geographical regions such as Canada, Alaska, California, Southwestern, Eastern and Southeastern USA, the Great Lakes region, the Great Plains, intermontane basins and plateaus, Rocky Mountains and the Cascades as well as Central and South America. We summarize main results of relevant field studies, experiments and model simulations. Predicted environmental changes include temperature increases, altering precipitation patterns, droughts, permafrost thaw and ground subsidence in arctic regions, enhanced El Niño Southern Oscillation, sea level rise, increasing salinity of the vadose zone, snowpack declines and various disturbances. All vegetation types are affected by these changes, to the most important phenomena belong e.g. reduction of arctic and alpine communities, decreasing area of taiga, shrub encroachment in tundra areas, northward expansion of the tree line, reduction in wetland areas, invasion, altering forest regeneration patterns, decrease in dominance of conifer species, increased cover of salt-tolerant plant species in tidal marshes, expansion of grassland, compositional and structural changes of grasslands and forests, drying up of bogs, landward migration of mangroves, savannification of forests, expansion of chaparral as well as upward migration of species in the mountains.

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Climate change and thresholds of biome shifts in Amazonia

Cited by 56 publications

References 39 publications

Land-use and climate change risks in the Amazon and the need of a novel sustainable development paradigm

Land-use and climate change risks in the Amazon and the need of a novel sustainable development paradigm

Land Use Change over the Amazon Forest and Its Impact on the Local Climate

Impacts of Climate Change on Vegetation Distribution No. 2 - Climate Change Induced Vegetation Shifts in the New World

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