نتایج جستجو برای: astara forest ecosystem

تعداد نتایج: 179070  

Journal: :Environmental pollution 1994
W A Kurz M J Apps

Ecosystem responses to climate changes will affect the exchange of carbon (C) with the atmosphere, thus providing feedback for future climate response. We have developed a C budget model of Canadian forests and forest sector activities and used sensitivity analysis runs with changes in productivity, decomposition, and disturbance regimes to assess the sensitivity of the Canadian forest sector C...

2012
Rodolfo Martinez Morales

Forests are complex ecosystems that develop over centuries through the interactions between organisms and biogeochemical cycles of elements occurring in the soil-atmosphere continuum. The biomass and structure of a forest stand is involved in several ecosystem processes and has been used as an indicator of forest health and productivity. The forest biomass is a key component of the carbon cycle...

1999
JINGSHENG LUAN YIQI LUO JAMES F. REYNOLDS

(FACE) facilities represents a substantial advance in experimental technology for studying ecosystem responses to elevated CO2. A challenge arising from the application of this technology is the utilization of short-term FACE results for predicting long-term ecosystem responses. This modeling study was designed to explore interactions of various processes on ecosystem productivity at elevated C...

2014
Yan Wang Jixi Gao Jinsheng Wang Jie Qiu

Changes in land use can cause significant changes in the ecosystem structure and process variation of ecosystem services. This study presents a detailed spatial, quantitative assessment of the variation in the value of ecosystem services based on land use change in national nature reserves of the Ningxia autonomous region in China. We used areas of land use types calculated from the remote sens...

Journal: :Global change biology 2013
E Louise Loudermilk Robert M Scheller Peter J Weisberg Jian Yang Thomas E Dilts Sarah L Karam Carl Skinner

Understanding how climate change may influence forest carbon (C) budgets requires knowledge of forest growth relationships with regional climate, long-term forest succession, and past and future disturbances, such as wildfires and timber harvesting events. We used a landscape-scale model of forest succession, wildfire, and C dynamics (LANDIS-II) to evaluate the effects of a changing climate (A2...

2014
Hai Ren Linjun Li Qiang Liu Xu Wang Yide Li Dafeng Hui Shuguang Jian Jun Wang Huai Yang Hongfang Lu Guoyi Zhou Xuli Tang Qianmei Zhang Dong Wang Lianlian Yuan Xubing Chen Ting Wang

Spatial and temporal patterns of carbon (C) storage in forest ecosystems significantly affect the terrestrial C budget, but such patterns are unclear in the forests in Hainan Province, the largest tropical island in China. Here, we estimated the spatial and temporal patterns of C storage from 1993-2008 in Hainan's forest ecosystems by combining our measured data with four consecutive national f...

2013
Clinton Innes Madhur Anand Chris T. Bauch

Forest-grassland mosaic ecosystems can exhibit alternative stables states, whereby under the same environmental conditions, the ecosystem could equally well reside either in one state or another, depending on the initial conditions. We develop a mathematical model that couples a simplified forest-grassland mosaic model to a dynamic model of opinions about conservation priorities in a population...

2007
V. Sinha J. Williams P. J. Crutzen

Methane is a climatologically important greenhouse gas, which plays a key role in regulating water vapour in the stratosphere and hydroxyl radicals in the troposphere. Recent findings that vegetation emits methane have stimulated efforts to ascertain the impact of this source on the global budget. In this work, we present the re-5 sults of high frequency (ca. 1 min −1) methane measurements cond...

1999
W. D. Potter

Forest ecosystems exhibit complex dynamics over time and space. Management of forest ecosystems involves the need to forecast future states of complex systems that are often undergoing structural changes. This in turn requires integration of quantitative science and engineering components with socio-political, regulatory, and economic considerations. The amount of data, information and knowledg...

Journal: :Tree physiology 1999
Jingsheng Luan Yiqi Luo James F. Reynolds

The development of the Free-Air CO(2) Enrichment (FACE) facilities represents a substantial advance in experimental technology for studying ecosystem responses to elevated CO(2). A challenge arising from the application of this technology is the utilization of short-term FACE results for predicting long-term ecosystem responses. This modeling study was designed to explore interactions of variou...

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