نتایج جستجو برای: deforestation

تعداد نتایج: 5221  

2016
Paulo Queiroz Sousa Andrew P. Vayda Eric J. Jokela

Forest conservation efforts through regulatory enforcement routinely failed to prevent large scale deforestation in the Brazilian Amazon. However, a turning point occurred in 2005, when a combination of unfavorable economic conditions and an unprecedented coordinated effort between governmental institutions resulted in a gradual slowdown in deforestation. The continuation of this deforestation ...

2004
Juan A. Robalino Alexander Pfaff

We estimate the effects of neighbors’ deforestation actions on individuals’ deforestation decisions in Costa Rica. We find evidence that neighbors’ effects are positive and significant. To address simultaneity and spatially correlated unobservable factors, we instrument for neighboring deforestation using neighboring land parcel characteristics. Under the presence of interactions, local forest ...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2014
Javier Godar Toby A Gardner E Jorge Tizado Pablo Pacheco

Annual deforestation rates in the Brazilian Amazon fell by 77% between 2004 and 2011, yet have stabilized since 2009 at 5,000-7,000 km(2). We provide the first submunicipality assessment, to our knowledge, of actor-specific contributions to the deforestation slowdown by linking agricultural census and remote-sensing data on deforestation and forest degradation. Almost half (36,158 km(2)) of the...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2006
Douglas C Morton Ruth S DeFries Yosio E Shimabukuro Liana O Anderson Egidio Arai Fernando del Bon Espirito-Santo Ramon Freitas Jeff Morisette

Intensive mechanized agriculture in the Brazilian Amazon grew by >3.6 million hectares (ha) during 2001-2004. Whether this cropland expansion resulted from intensified use of land previously cleared for cattle ranching or new deforestation has not been quantified and has major implications for future deforestation dynamics, carbon fluxes, forest fragmentation, and other ecosystem services. We c...

Journal: :Science 1993
D Skole C Tucker

Landsat satellite imagery covering the entire forested portion of the Brazilian Amazon Basin was used to measure, for 1978 and 1988, deforestation, fragmented forest, defined as areas less than 100 square kilometers surrounded by deforestation, and edge effects of 1 kilometer into forest from adjacent areas of deforestation. Tropical deforestation increased from 78,000 square kilometers in 1978...

2013
David W. Shaw Patricia Escalante John H. Rappole Mario A. Ramos Richard J. Oehlenschlager Dwain W. Warner Kevin Winker

How avifauna respond to the long-term loss and fragmentation of tropical forests is a critical issue in biodiversity management. We use data from over 30 years to gain insights into such changes in the northernmost Neotropical rainforest in the Sierra de Los Tuxtlas of southern Veracruz, Mexico. This region has been extensively deforested over the past half-century. The Estación de Biología Tro...

2013
Ghislain Vieilledent Clovis Grinand Romuald Vaudry

Anthropogenic deforestation in tropical countries is responsible for a significant part of global carbon dioxide emissions in the atmosphere. To plan efficient climate change mitigation programs (such as REDD+, Reducing Emissions from Deforestation and forest Degradation), reliable forecasts of deforestation and carbon dioxide emissions are necessary. Although population density has been recogn...

2018
Vahid Ahmadi

Deforestation, as one of the challenging environmental problems in the world, has been recorded the most serious threat to environmental diversity and one of the main components of land-use change. In this paper, we investigate spatial distribution of deforestation using artificial neural networks and satellite imagery. Modeling deforestation can be conducted considering various factors in dete...

Journal: :Ambio 2003
Philip M Fearnside

Controlling deforestation in Brazil's Amazon region has long been illusive despite repeated efforts of government authorities to slow the process. From 1997 to 2000, deforestation rates in Brazil's 9-state "Legal Amazon" region continually crept upward. Now, a licensing and enforcement program for clearing by large farmers and ranchers in the state of Mato Grosso appears to be having an effect....

2003
James R. Kahn Judith A. McDonald

The deforestation and degradation of tropical forests are taking place at an extremely rapid pace. According to the Food and Agriculture Organization (FAO), the estimated annual rate of tropical deforestation during the 1981-1985 period was 113 846 square kilometers or 0.6% of the 1981 total forested area. The implications of the loss of these forests are staggering (Myers, N., 1989. Deforestat...

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