نتایج جستجو برای: forest ecosystems

تعداد نتایج: 144986  

2014
Wenping Sheng Guirui Yu Huajun Fang Yingchun Liu Qiufeng Wang Zhi Chen Li Zhang

The regional determining factors underlying inter- and intra-site variation of (15)N natural abundance in foliage, O horizon and mineral soil were investigated in eastern China.(15)N natural abundance values for these forest ecosystems were in the middle of the range of values previously found for global forest ecosystems. In contrast to commonly reported global patterns, temperate forest ecosy...

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: :Forest Ecosystems 2014

Journal: :Molecular ecology 2010
Ivan P Edwards Donald R Zak

The Agaricomycotina are a phylogenetically diverse group of fungi that includes both saprotrophic and mycorrhizal species, and that form species--rich communities in forest ecosystems. Most species are infrequently observed, and this hampers assessment of the role that environmental heterogeneity plays in determining local community composition and in driving beta-diversity. We used a combinati...

2005
Neil W. Foster Jagtar S. Bhatti

Nutrients are elements or compounds that are essential for the growth and survival of plants. Plants require large amounts of nutrients such as nitrogen (N), phosphorus (P), carbon (C), hydrogen (H), oxygen (O), potassium (K), calcium (Ca), and magnesium (Mg), but only small amounts of others such as boron (B), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn) and chlorine (Cl) (micronutrients)...

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...

2005
John J. Battles Robert C. Heald

The core assumption of this symposium is that science can provide insight to management. Nowhere is this link more formally established than in regard to the science and management of forest ecosystems. The basic questions addressed are integral to our understanding of nature; the applications of this understanding are crucial to effective stewardship of natural resources (Carpenter and Turner ...

Journal: :محیط زیست طبیعی 0
زهرا نوری دانش آموختۀ دکتری جنگل داری، دانشکدۀ منابع طبیعی، دانشگاه تهران، ایران محمود زبیری استاد گروه جنگل داری و اقتصاد جنگل، دانشکدۀ منابع طبیعی، دانشگاه تهران، ایران جهانگیر فقهی دانشیار گروه جنگل داری و اقتصاد جنگل دانشکدۀ منابع طبیعی، دانشگاه تهران، ایران محمدرضا مروی مهاجر استاد گروه جنگل داری و اقتصاد جنگل، دانشکدۀ منابع طبیعی، دانشگاه تهران، ایران

beech forests in midland areas of hyrcanian forests of iran are the most important forests having the highest degree of naturalness. these forests are the valuable source of wood production and other forest products. one of the most important characteristics of plant communities is the spatial pattern of trees. ecological process in forest ecosystems are directly influenced by the spatial patte...

Journal: :Small Business Economics 2022

Abstract Despite the emerging body of literature on entrepreneurial ecosystems (EEs), theoretical development is still in its infancy. In this article, we explicitly draw upon analogy forest (FEs) with an EE to extrapolate regional ecosystem (REE) as alternate conceptual framework. The REE considers a region’s socioeconomic activity and stability performance whole, influenced by partitioned int...

2012
Katarína Merganičová Ján Merganič Miroslav Svoboda Radek Bače Vladimír Šebeň

Until recently, deadwood was perceived as a negative element of forest ecosystems, that indicates “mismanagement, negligence, and wastefulness” of the applied forest management (Stachura et al., 2007). It was regarded as a potential source of biotic pests, mainly insects (Bütler, 2003; Marage & Lemperiere, 2005), to remaining trees in a forest as well as to adjacent stands (Pasierbek et al., 20...

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