نتایج جستجو برای: forest clearing

تعداد نتایج: 113265  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2008
Matthew C Hansen Stephen V Stehman Peter V Potapov Thomas R Loveland John R G Townshend Ruth S DeFries Kyle W Pittman Belinda Arunarwati Fred Stolle Marc K Steininger Mark Carroll Charlene Dimiceli

Forest cover is an important input variable for assessing changes to carbon stocks, climate and hydrological systems, biodiversity richness, and other sustainability science disciplines. Despite incremental improvements in our ability to quantify rates of forest clearing, there is still no definitive understanding on global trends. Without timely and accurate forest monitoring methods, policy r...

Journal: :Population research and policy review 2007
William Pan David Carr Alisson Barbieri Richard Bilsborrow Chirayath Suchindran

This study tests four hypotheses related to forest clearing over time in Ecuador's northern Amazon: (1) a larger increase in population over time on a farm (finca) leads to more deforestation; (2) rates of forest clearing surrounding four primary reference communities differ (spatial heterogeneity); (3) fincas farther from towns/communities experience lower rates of forest clearing over time; a...

2017
Alexandra Tyukavina Matthew C. Hansen Peter V. Potapov Stephen V. Stehman Kevin Smith-Rodriguez Chima Okpa Ricardo Aguilar

Deforestation rates in primary humid tropical forests of the Brazilian Legal Amazon (BLA) have declined significantly since the early 2000s. Brazil's national forest monitoring system provides extensive information for the BLA but lacks independent validation and systematic coverage outside of primary forests. We use a sample-based approach to consistently quantify 2000-2013 tree cover loss in ...

Journal: :journal of agricultural science and technology 0
h. asadi department of soil science, faculty of agricultural engineering and technology, university of tehran, karaj, islamic republic of iran. m. honarmand department of soil science, faculty of agricultural sciences, university of guilan, rasht, islamic republic of iran. m. vazifedoust department of soil science, faculty of agricultural sciences, university of guilan, rasht, islamic republic of iran. a. moussavi department of soil science, faculty of agricultural sciences, university of guilan, rasht, islamic republic of iran.

risk assessment of soil erosion, one of the most important land degradation problems worldwide, is very essential for land and water resources management, and development of soil conservation methods. in the present study, the temporal changes of soil erosion risk were assessed from 1987 to 2010, based on the revised universal soil loss equation (rusle) using remote sensing (rs) and geographic ...

2017
Naomi B Schwartz María Uriarte Ruth DeFries Victor H Gutierrez-Velez

Many countries have made major commitments to carbon sequestration through reforestation under the Paris Climate Agreement, and recent studies have illustrated the potential for large amounts of carbon sequestration in tropical second-growth forests. However, carbon gains in second-growth forests are threatened by non-permanence, i.e. release of carbon into the atmosphere from clearing or distu...

2016
Hua Zhou Shengwang Meng Juan Carlos Linares

Sustained forest management of Cunninghamia lanceolata (Chinese fir) plantations in subtropical China is restricted by the limited availability of quantitative data. This study combines inventory data and tree-ring analysis of Chinese fir from natural and plantation forests that were subjected to controlled burning or brush clearing site preparations. Inter-annual variation of Chinese fir tree-...

2015
RONNIE BABIGUMIRA ARILD ANGELSEN SVEN WUNDER

This paper examines the factors that influence rural household decisions to clear forestland. We use a large dataset com prising 7172 households from 24 developing countries. Twenty seven percent of sampled households had converted forest to agriculture during the previous 12 months, clearing on average 1.21 ha. Male headed households with abundance of male labor, living in recently settled pla...

2016
Leena Korpinen Harri Kuisti Jarmo Elovaara

The aim of the study was to analyze all values of electric currents from measured periods while performing tasks in forest clearing. The objective was also to choose and analyze measurement cases, where current measurements successfully lasted the entire work period (about 30 min). Two forestry workers volunteered to perform four forest clearing tasks under 400 kV power lines. The sampling freq...

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: :The Journal of animal ecology 2009
Anjali Kumar Sean O'Donnell

1. Forest fragmentation often results in a matrix of open areas mixed with patches of forest. Both biotic and abiotic factors can affect consumer species' ability to utilize the altered habitat, especially for species that range over large areas searching for prey. 2. Army ants (Formicidae: Ecitoninae) are highly mobile top predators in terrestrial Neotropical ecosystems. Army ant foraging beha...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید