Desertification
Mostrando 49-57 de 57 artigos, teses e dissertações.
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49. Climatic consequences of vegetation changes in Northeast Brazil: A AGM simulation study / Conseqüências climáticas da mudança de vegetação do Nordeste brasileiro: um estudo de modelagem
Realiza-se um estudo de modelagem para avaliar as consequências climáticas de alterações da vegetação do Nordeste brasileiro (NEB). Utiliza-se o MCGA do CPTEC/COLA. Na parte I, mantêm-se os biomas fixos durante toda a integração. No controle, o NEB 6 coberto por caatinga. No experimento de desertificação, converte-se a caatinga do NEB para solo nu
Publicado em: 2002
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50. Conseqüências climáticas da mudança de vegetação do Nordeste brasileiro: um estudo de modelagem / Climatic consequences of vegetation changes in Northeast Brazil: A AGM simulation study
Realiza-se um estudo de modelagem para avaliar as consequências climáticas de alterações da vegetação do Nordeste brasileiro (NEB). Utiliza-se o MCGA do CPTEC/COLA. Na parte I, mantêm-se os biomas fixos durante toda a integração. No controle, o NEB 6 coberto por caatinga. No experimento de desertificação, converte-se a caatinga do NEB para solo nu
Publicado em: 2002
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51. x / Experimentos numericos com modelos climaticos media zonal
Two statistical-dynamical models, a quasi-geostrophic and a primitive equations model are developed. These are used to conduct numerical experiments about the zonally-averaged atmosphere, with emphasis on the Southern Hemisphere climatic processes. The experiments consider the climatic effects caused by the sea-surface temperature (SST) anomalies and by land
Publicado em: 1989
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52. Reorganization of an arid ecosystem in response to recent climate change
Natural ecosystems contain many individuals and species interacting with each other and with their abiotic environment. Such systems can be expected to exhibit complex dynamics in which small perturbations can be amplified to cause large changes. Here, we document the reorganization of an arid ecosystem that has occurred since the late 1970s. The density of
The National Academy of Sciences of the USA.
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53. Management of Indigenous Plant-Microbe Symbioses Aids Restoration of Desertified Ecosystems
Disturbance of natural plant communities is the first visible indication of a desertification process, but damage to physical, chemical, and biological soil properties is known to occur simultaneously. Such soil degradation limits reestablishment of the natural plant cover. In particular, desertification causes disturbance of plant-microbe symbioses which ar
American Society for Microbiology.
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54. Desert dust suppressing precipitation: A possible desertification feedback loop
The effect of desert dust on cloud properties and precipitation has so far been studied solely by using theoretical models, which predict that rainfall would be enhanced. Here we present observations showing the contrary; the effect of dust on cloud properties is to inhibit precipitation. Using satellite and aircraft observations we show that clouds for
The National Academy of Sciences.
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55. Long-term human response to uncertain environmental conditions in the Andes
Human interaction with the physical environment has increasingly transformed Earth-system processes. Reciprocally, climate anomalies and other processes of environmental change of natural and anthropogenic origin have been affecting, and often disrupting, societies throughout history. Transient impact events, despite their brevity, can have significant long-
National Academy of Sciences.
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56. Are there ecological limits to population?
Policy on population and environment in the United States and abroad has been vacillating, unsure of its course; it would be more decisive if the several disciplines could agree on the nature of the problems and their urgency. The two disciplines principally concerned are biology and economics, and the contribution of this paper is to identify eight of the m
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57. Cross-scale interactions, nonlinearities, and forecasting catastrophic events
Catastrophic events share characteristic nonlinear behaviors that are often generated by cross-scale interactions and feedbacks among system elements. These events result in surprises that cannot easily be predicted based on information obtained at a single scale. Progress on catastrophic events has focused on one of the following two areas: nonlinear dynami
National Academy of Sciences.