نتایج جستجو برای: forest species changing

تعداد نتایج: 771031  

2004
DAVID T. PRICE NIKLAUS E. ZIMMERMANN MANFRED J. LEXER PAUL LEADLEY T. M. JORRITSMA JÖRG SCHABER DONALD F. CLARK PETRA LASCH STEVE MCNULTY JIANGUO WU BENJAMIN SMITH

Recruitment algorithms in forest gap models are examined with particular regard to their suitability for simulating forest ecosystem responses to a changing climate. The traditional formulation of recruitment is found limiting in three areas. First, the aggregation of different regeneration stages (seed production, dispersal, storage, germination and seedling establishment) is likely to result ...

Drought and grazing rangelands play an important role in changing the structure of vegetation and losing the biodiversity of natural ecosystems. In this research, in order to determine the effects of drought and livestock grazing on the vegetation structure of rangelands located in the Nakhab Forest of South Khorasan Province, species abundance, biodiversity, and range condition and trend were ...

2007
ANDRÉS M. CUERVO

Habitat fragmentation has the potential to influence the development and thus the phenotype of organisms. The asymmetry of bilateral traits may be indicative of the extent to which developmental stability is compromised by the stressful conditions underlying fragmentation. Using an assemblageand population-level approach, we explored asymmetry differences in tarsus and outermost tail feathers o...

Journal: :Remote Sensing 2013
Eliakim Hamunyela Jan Verbesselt Gerbert Roerink Martin Herold

Plant phenology is changing because of recent global warming, and this change may precipitate changes in animal distribution (e.g., pests), alter the synchronization between species, and have feedback effects on the climate system through the alteration of biogeochemical and physical processes of vegetated land surface. Here, ground observations (leaf unfolding/first leaf separation of six deci...

2007
Samuel A. Cushman Donald McKenzie David L. Peterson Jeremy Littell Kevin S. McKelvey

Reliable predictions of how changing climate and disturbance regimes will affect forest ecosystems are crucial for effective forest management. Current fire and climate research in forest ecosystem and community ecology offers data and methods that can inform such predictions. However, research in these fields occurs at different scales, with disparate goals, methods, and context. Often results...

2016
Josué H. Rakotoniaina Peter M. Kappeler Pascaline Ravoniarimbinina Eva Pechouskova Anni M. Hämäläinen Juliane Grass Clemens Kirschbaum Cornelia Kraus

Understanding how animals react to human-induced changes in their environment is a key question in conservation biology. Owing to their potential correlation with fitness, several physiological parameters are commonly used to assess the effect of habitat disturbance on animals' general health status. Here, we studied how two lemur species, the fat-tailed dwarf lemur (Cheirogaleus medius) and th...

Journal: :جنگل و فرآورده های چوب 0
سمیه کرمی راد دانشگاه تهران احسان عبدی دانشکده منابع طبیعی باریس مجنونیان دانشگاه تهران وحید اعتماد دانشگاه تهران هرمز سهرابی دانشگاه تربیت مدرس

road construction is one of the effective factors for ecological changes which affects diversity and species composition in forest roads edges. this research was performed in kheirud forest to evaluate herbaceous diversity and tree regeneration establishment in different distances from road edge. for this purpose, we sampled herbaceous and tree species regeneration in 0,5,10,25, 50 and 100 m di...

Journal: :محیط زیست طبیعی 0
ساره حسینی دانشجوی دکتری جنگلداری دانشکده منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری سید عطاء اله حسینی دانشیار گروه جنگلدای و اقتصاد جنگل دانشگاه تهران

in this study, species richness, evenness and vegetation biodiversity were investigated in stabilized and non-stabilized cut edge areas of chachkam district forest roads in sari forest of iran. 18 micro plots 1×1m (36 micro plots) were sampled to carry out this research on two cut edge areas. number of trees, shrubs and herbaceous were recorded in each micro-plot. significant difference was inv...

2010
Kevin M. Potter William W. Hargrove Frank H. Koch

—Climate change will likely pose a severe threat to the viability of certain forest tree species, which will be forced either to adapt to new conditions or to shift to more favorable environments if they are to survive. Several forest tree species of the central and southern Appalachians may be at particular risk, since they occur in limited high-elevation ranges and/or are currently threatened...

Journal: :environmental resources research 2014
hossein varasteh moradi mohamed zakaria scott . k. robinson

forest fragmentation results in a loss of forest interior and an increase in edge habitat. we studied how understorey bird community composition and habitat variables changed along an edge-to-interior gradient in a 1248-ha lowland rainforest patch in peninsular malaysia. birds and environmental variables such as vegetation structure and litter depth were detected within a 25-m radius of each of...

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