نتایج جستجو برای: astara forest ecosystem

تعداد نتایج: 179070  

Aidin Parsakhoo Ataollah Kavian Atta Safari,

Forests are an important economic source for human and have key role in nutrient cycle, hydrology and ecosystem performance, any interference in this vital ecosystem causes to damage to forests. Mechanical logging and road construction in forest areas have led to much soil compaction. Soil physical and chemical properties were studied in parts of road and non-road in the Darabkola forest of Ira...

2014
Wenping Sheng Guirui Yu Huajun Fang Chunming Jiang Junhua Yan Mei Zhou

We added the stable isotope (15)N in the form of ((15)NH4)2SO4 and K(15)NO3 to forest ecosystems in eastern China under two different N deposition levels to study the fate of the different forms of deposited N. Prior to the addition of the (15)N tracers, the natural (15)N abundance ranging from -3.4‰ to +10.9‰ in the forest under heavy N deposition at Dinghushan (DHS), and from -3.92‰ to +7.25‰...

Journal: :Ecological Informatics 2012
Junbin Zhao Yiping Zhang Zhenghong Tan Qinghai Song Naishen Liang Lei Yu Junfu Zhao

a Key Lab of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan 666303, China b Ailaoshan Station for Subtropical Forest Ecosystem Research, Chinese Ecosystem Research Networks, Jingdong, Yunnan 676209, China c National Forest Ecosystem Research Station at Ailaoshan, Jingdong, Yunnan 676209, China d Center for Global Environmental Rese...

1998
Stephen K. Swallow Piyali Talukdar David N. Wear

“Ecosystem management” complicates forest management considerably. In this paper we extend the economic analysis of forestry to capture both the temporal and the spatial dimensions, allowing optimization of timber harvest decisions throughout an ecosystem. Dynamic programming simulations illustrate the implications for the simplest ecosystem, consisting of two forest management units. Results i...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1997
G E Likens S L Tartowski T W Berger D G Richey C T Driscoll H G Frank A Klein

Although trifluoroacetate (TFA), a breakdown product of chlorofluorocarbon replacements, is being dispersed widely within the biosphere, its ecological fate is largely unknown. TFA was added experimentally to an upland, northern hardwood forest and to a small forest wetland ecosystem within the Hubbard Brook Experimental Forest in New Hampshire. Inputs of TFA were not transported conservatively...

Journal: :Ying yong sheng tai xue bao = The journal of applied ecology 2005
Jin Fang Shaowei Lu Xinxiao Yu Liangyi Rao Jianzhi Niu Yuanyuan Xie Zhenming Zhag

Facing the relative lag of forest ecosystem service and estimation in China, this paper proposed to quickly carry out the research on the evaluation of forest ecosystem service. On the basis of the classification of forest ecosystem types in China, the service of artificial and semi-artificial forest ecosystems was investigated, which was divided into eight types, i.e., timber and other product...

This study investigates the role of man-made disturbance on on nitrogen and phosphorus nutrient storage by herbaceous species in Gall Oak stands of Lorestan province. In order to do this study, two sites with the same physiographic and ecological conditions and different land uses were selected. Multiscale sampling plots were used randomly in each site to collect data on forest floor vegetation...

2016
Alexander K. Guts Ludmila A. Volodchenkova

To find the possible equilibrium states of forest ecosystems one are suggested to use the theory of differential games. At within the 4-tier model of mosaic forest communities it established the existence of the Nash equilibrium states in such ecosystems. Key–Words: Forest ecosystem, the equilibrium of the ecosystem, differential game, Nash equilibrium October 30, 2016

Journal: :Ecological applications : a publication of the Ecological Society of America 2007
Akiko Satake Thomas K Rudel

An historical generalization about forest cover change in which rapid deforestation gives way over time to forest restoration is called "the forest transition." Prior research on the forest transition leaves three important questions unanswered: (1) How does forest loss influence an individual landowner's incentives to reforest? (2) How does the forest recovery rate affect the likelihood of for...

1996
Masanobu Shimada

I The Amazon rain forest is a region of the earth that is undergoing rapid change. Man-made disturbance, such as clear cutting for agriculture or mining, is altering the rain forest ecosystem. For many parts of the rain forest, seasonal changes from the wet to the dry season are also significant. Changes in the seasonal cycle of floocfing and draining can cause significant alterations in the fo...

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