File Name: effects of tropical deforestation on climate and agriculture .zip
Skip to search form Skip to main content You are currently offline. Some features of the site may not work correctly. DOI: Lawrence and K. Lawrence , K. Tropical forests provide many ecosystem and climatic services. This Review provides a synthesis of the effects of tropical deforestation on climate and implications for agriculture, both in the tropics and worldwide.
Metrics details. Some evidence suggests that forests attract rain and that deforestation contributes to changes in rainfall and temperature. The evidence, however, is scant, particularly on smaller spatial scales. The specific objectives of the study were: i to evaluate long-term trends in rainfall — and temperature — and their relationships with change in forest cover, and ii to assess the influence of remnant forests and topographical factors on the spatial variability of annual rainfall. This study investigated the forest-rainfall relationships in the Central Rift Valley of Ethiopia. The study used 16 long-term — and 15 short-term — rainfall and six long term — temperature datasets. The long-term trends in rainfall — and temperature — were determined using Mann-Kendall MK and Regional Kendall RK tests and their relationships with long-term deforestation were evaluated using simple linear regression.
The United States Environmental Protection Agency defines deforestation as the "permanent removal of standing forests. Deforestation is the clearing, destroying, or otherwise removal of trees through deliberate, natural, or accidental means. It can occur in any area densely populated by trees and other plant life, but the majority of it is currently happening in the Amazon rainforest. The loss of trees and other vegetation can cause climate change, desertification, soil erosion, fewer crops, flooding, increased greenhouse gases in the atmosphere, and a host of problems for indigenous people. It was only after the onset of the modern era that it became an epidemic.
Tropical forests are a major source of global hydrologic fluxes, profoundly influencing both global and regional climates see Kumagai et al. Humans have been modifying tropical forest land cover for food and energy production and for the development of tropical countries. Consequently, such modifications, that is, land use and land cover change LULCC , are being combined with climate change and are anticipated to impact the climate on local, regional, and even global scales via teleconnections Werth and Avissar ; Medvigy et al. Lawrence and Vandecar summarized difficulties in projecting the precipitation change induced by tropical deforestation on continental and local scales; for example, precipitation could be reduced or enhanced in accordance with the size and state of deforestation a single large patch is similar to distributed patches. Here, we must note that, in turn, such LULCC-driven hydroclimate change could lead to significant negative impacts on tropical forest ecological patterns and processes see Malhi et al.
Pablo O. Most experimental and modeling studies have focused on the resulting perturbations within Amazonia. Precipitation changes for and land-use scenarios, while significant within deforested areas, do not result in significant regional changes. For temperature significant changes are found within deforested areas and beyond, with major temperature enhancements during winter and spring.
Deforestation , clearance , clearcutting , or clearing is the removal of a forest or stand of trees from land that is then converted to non-forest use. The most concentrated deforestation occurs in tropical rainforests. The Food and Agriculture Organization of the United Nations defines deforestation as the conversion of forest to other land uses regardless of whether it is human-induced. Net change, therefore, can be positive or negative, depending on whether gains exceed losses, or vice versa.
Large-scale conversion of tropical forests into pastures or annual crops will likely lead to changes in the local microclimate of those regions. Larger diurnal fluctuations of surface temperature and humidity deficit, increased surface runoff during rainy periods and decreased runoff during the dry season, and decreased soil moistrue are to be expected. It is likely that evapotranspiration will be reduced because of less available radiative energy at the canopy level since grass presents a higher albedo than forests, also because of the reduced availability of soil moisture at the rooting zone primarily during the dry season. Recent results from general circulation model GCM simulations of Amazonian deforestation seem to suggest that the equilibrium climate for a grassy vegetation in Amazonia would be one in which regional precipitation would be significantly reduced. Global climate changes probably will occur if there is a marked change in rainfall patterns in tropical forest regions as a result of deforestation. Besides that, biomass burning of tropical forests is likely adding CO 2 into the atmosphere, thus contributing to the enhanced greenhouse warming.
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Deforestation is associated with increased atmospheric CO 2 and alterations to the surface energy and mass balances that can lead to local and global climate changes. Previous modelling studies show that the global surface air temperature SAT response to deforestation depends on latitude, with most simulations showing that high latitude deforestation results in cooling, low latitude deforestation causes warming and that the mid latitude response is mixed. These earlier conclusions are based on simulated large scal land cover change, with complete removal of trees from whole latitude bands.
Бринкерхофф послушно следил за движениями ее пальца. КОЛИЧЕСТВО ДЕШИФРОВОК О Мидж постучала пальцем по этой цифре. - Я так и думала.
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