نتایج جستجو برای: land productivity

تعداد نتایج: 198818  

2014
XIMING CAI

Growing biomass feedstocks from marginal lands is becoming an increasingly attractive choice for producing biofuel as an alternative energy to fossil fuels. Here, we used a biogeochemical model at ecosystem scale to estimate crop productivity and greenhouse gas (GHG) emissions from bioenergy crops grown on marginal lands in the United States. Two broadly tested cellulosic crops, switchgrass, an...

2017
I.P. Holman C Brown V Janes D Sandars

The global land system is facing unprecedented pressures from growing human populations and climatic change. Understanding the effects these pressures may have is necessary to designing land management strategies that ensure food security, ecosystem service provision and successful climate mitigation and adaptation. However, the number of complex, interacting effects involved makes any complete...

Journal: :Population and environment 2010
Douglas S Massey William G Axinn Dirgha J Ghimire

Scholars and activists have hypothesized a connection between environmental change and out-migration. In this paper we test this hypothesis using data from Nepal. We operationalize environmental change in terms of declining land cover, rising times required to gather organic inputs, increasing population density, and perceived declines in agricultural productivity. In general, environmental cha...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2013
Cory C Cleveland Benjamin Z Houlton W Kolby Smith Alison R Marklein Sasha C Reed William Parton Stephen J Del Grosso Steven W Running

Nitrogen (N) and phosphorus (P) availability regulate plant productivity throughout the terrestrial biosphere, influencing the patterns and magnitude of net primary production (NPP) by land plants both now and into the future. These nutrients enter ecosystems via geologic and atmospheric pathways and are recycled to varying degrees through the plant-soil-microbe system via organic matter decay ...

Journal: :Journal of environmental management 2007
X Feng G Liu J M Chen M Chen J Liu W M Ju R Sun W Zhou

The terrestrial carbon cycle is one of the foci in global climate change research. Simulating net primary productivity (NPP) of terrestrial ecosystems is important for carbon cycle research. In this study, China's terrestrial NPP was simulated using the Boreal Ecosystem Productivity Simulator (BEPS), a carbon-water coupled process model based on remote sensing inputs. For these purposes, a nati...

2008
Jochem Liem Floris Linnebank Anders Bouwer

The Riacho Fundo qualitative model, a product of the Brazilian case study run by the Univeristy of Brasilia in Naturnet project, was evaluated by stakeholders. The Riacho Fundo basin is located near Brasilia, the new capital, and changes in land use are held responsible for major changes in the area, including deforestation, erosion, loss of biodiversity and water resources, and decrease in eco...

2003
Lire Ersado Gregory Amacher Jeffrey Alwang

EPTD Discussion Papers contain preliminary material and research results, and are circulated prior to a full peer review in order to stimulate discussion and critical comment. It is expected that most Discussion Papers will eventually be published in some other form, and that their content may also be revised. PRODUCTIVITY AND LAND ENHANCING TECHNOLOGIES IN NORTHERN ETHIOPIA: HEALTH, PUBLIC INV...

Journal: :ISPRS Int. J. Geo-Information 2017
Rajchandar Padmanaban Avit K. Bhowmik Pedro Cabral

Mining for resources extraction may lead to geological and associated environmental changes due to ground movements, collision with mining cavities, and deformation of aquifers. Geological changes may continue in a reclaimed mine area, and the deformed aquifers may entail a breakdown of substrates and an increase in ground water tables, which may cause surface area inundation. Consequently, a r...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2014
W Jesse Hahm Clifford S Riebe Claire E Lukens Sayaka Araki

Earth's land surface teems with life. Although the distribution of ecosystems is largely explained by temperature and precipitation, vegetation can vary markedly with little variation in climate. Here we explore the role of bedrock in governing the distribution of forest cover across the Sierra Nevada Batholith, California. Our sites span a narrow range of elevations and thus a narrow range in ...

2015
Brittain M. Briber Lucy R. Hutyra Andrew B. Reinmann Steve M. Raciti Victoria K. Dearborn Christopher E. Holden Allison L. Dunn Shuqing Zhao

Urban areas are expanding, changing the structure and productivity of landscapes. While some urban areas have been shown to hold substantial biomass, the productivity of these systems is largely unknown. We assessed how conversion from forest to urban land uses affected both biomass structure and productivity across eastern Massachusetts. We found that urban land uses held less than half the bi...

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