نتایج جستجو برای: forest floor vegetation

تعداد نتایج: 175675  

2004
Katherine J. Elliott James M. Vose Barton D. Clinton Jennifer D. Knoepp

Information is lacking on ecosystem effects of understory burning in mesic mixed-oak (Quercus spp.) forests of the southern Appalachians. Native Americans used periodic fires in these forests for driving game and opening the forest. In April 1998, we conducted a lowto moderate-intensity fire in a cove–hardwood forest in the Nantahala National Forest, western North Carolina. In March 1998, befor...

2017
Norbert Helm Franz Essl Michael Mirtl Thomas Dirnböck

Human-induced changes of the environment and their possible impacts on temperate forest understory plant communities have been examined in many studies. However, the relative contribution of individual environmental factors to these changes in the herb layer is still unclear. In this study, we used vegetation survey data covering a time period of 21 years and collected from 143 permanent plots ...

2006
J. M. Vose P. V. Bolstad

We measured forest floor C02 flux in three age classes of forest in the southern Appalachians: 20-year-old, 85-year-old, and old-growth. Our objectives were to quantify differences in forest floor C02 flux among age classes, and determine the relative importance of abiotic and biotic driving variables. Forest floor C02 flux was measured using an openflow infrared gas analyzer measurement system...

2012
Dale W. Johnson Roger F. Walker Michelle McNulty Benjamin M. Rau

This paper compares carbon (C) and nutrient contents in soils (Alfisols derived from andesite), forest floor and vegetation in a former fire (1960) and an adjacent forest in the Sagehen Watershed in the Sierra Nevada Mountains of California. Soils from the former fire (now occupied predominantly by Ceanothus velutinus, a nitrogen-fixing shrub) had significantly lower contents of extractable SO4...

Journal: :Tree physiology 1990
Paul J. Curran Jennifer L. Dungan Henry L. Gholz

Chlorophyll is a key indicator of the physiological status of a forest canopy. However, its distribution may vary greatly in time and space, so that the estimation of chlorophyll content of canopies or branches by extrapolation from leaf values obtained by destructive sampling is labor intensive and potentially inaccurate. Chlorophyll content is related positively to the point of maximum slope ...

2016
Ayako Izuno Mamoru Kanzaki Taksin Artchawakom Chongrak Wachrinrat Yuji Isagi

Phyllosphere fungi harbor a tremendous species diversity and play important ecological roles. However, little is known about their distribution patterns within forest ecosystems. We examined how species diversity and community composition of phyllosphere fungi change along a vertical structure in a tropical forest in Thailand. Fungal communities in 144 leaf samples from 19 vertical layers (1.28...

2013
Li-hua Tu Ting-xing Hu Jian Zhang Li-hua Huang Yin-long Xiao Gang Chen Hong-ling Hu Li Liu Jiang-kun Zheng Zhen-feng Xu Liang-hua Chen

BACKGROUND The hydrological cycle is an important way of transportation and reallocation of reactive nitrogen (N) in forest ecosystems. However, under a high level of atmospheric N deposition, the N distribution and cycling through water flows in forest ecosystems especially in bamboo ecosystems are not well understood. METHODOLOGY/PRINCIPAL FINDINGS In order to investigate N fluxes through w...

2012
Brooke E. Crowley Keriann C. McGoogan Shawn M. Lehman

Edge effects represent an inevitable and important consequence of habitat loss and fragmentation. These effects include changes in microclimate, solar radiation, or temperature. Such abiotic effects can, in turn, impact biotic factors. They can have a substantial impact on species, communities, and ecosystems. Here we examine clinal variations in stable carbon and nitrogen isotope values for tr...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم کشاورزی و منابع طبیعی گرگان - دانشکده جنگلداری و مهندسی چوب و کاغذ 1386

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