نتایج جستجو برای: natural forest

تعداد نتایج: 576922  

2005
Kevin L. O’Hara

A general premise of forest managers is that modern silviculture should be based, in large part, on natural disturbance patterns and species' adaptations to these disturbances. An understanding of forest stand dynamics is therefore a prerequisite to sound forest management. This paper provides a brief overview of forest stand development, stand structures, and disturbance regimes and discusses ...

2015
Ingo Grass Roland Brandl Alexandra Botzat Eike Lena Neuschulz Nina Farwig

The degradation of natural forests to modified forests threatens subtropical and tropical biodiversity worldwide. Yet, species responses to forest modification vary considerably. Furthermore, effects of forest modification can differ, whether with respect to diversity components (taxonomic or phylogenetic) or to local (α-diversity) and regional (β-diversity) spatial scales. This real-world comp...

2006
Lisa Naughton-Treves Daniel M. Kammen Colin Chapman

Woodfuels are the most heavily used energy source in sub-Saharan Africa. We analyzed the ecological impacts and modes of access of five user groups (domestic consumers, gin distillers, brick manufacturers, charcoal producers, and tea companies) drawing biomass energy from natural forests in western Uganda. While domestic consumers use the most species for fuelwood (>50), their consumption is li...

2017
Bin Ma Zhongmin Dai Haizhen Wang Melissa Dsouza Xingmei Liu Yan He Jianjun Wu Jorge L M Rodrigues Jack A Gilbert Philip C Brookes Jianming Xu

The natural forest ecosystem in Eastern China, from tropical forest to boreal forest, has declined due to cropland development during the last 300 years, yet little is known about the historical biogeographic patterns and driving processes for the major domains of microorganisms along this continental-scale natural vegetation gradient. We predicted the biogeographic patterns of soil archaeal, b...

گونه راش یکی از فراوانترین و از نظر اقتصادی مهمترین درختان جنگلهای شمال ایران است. تعیین ساختار هر توده و ترکیب آن با خصوصیات جنگل‌شناسی که شامل آمیختگی، سن، ساختار عمودی یا اشکوب‌بندی، ساختار افقی، وجود یا عدم وجود روزنه، تاج پوشش، انبوهی، وجود و یا عدم وجود زادآوری یا زیراشکوب درختی و درختچه‌ای است می‌تواند ما را در دستیابی به یک مدیریت مناسب و فراگیر، یاری نماید. در این پژوهش خصوصیات مورفول...

ژورنال: علوم آب و خاک 2007
جمشید مختاری, , حمید جلیلوند, , سید فضل الله عمادیان, , سید احسان ساداتی, , مسعود طبری, ,

The present research was conducted to find the influence of some topographic factors on distribution of large-leaved lime (Tilia platyphyllos Scop.) and its natural regeneration characteristics in "Vaz" forest (northern Iran). After identification of site and preparation of topography map, selective sampling method was carried out for tree inventory in plots. The sample plots were circular in 1...

2012
Marion Pfeifer Neil D. Burgess Ruth D. Swetnam Philip J. Platts Simon Willcock Robert Marchant

In East Africa, human population growth and demands for natural resources cause forest loss contributing to increased carbon emissions and reduced biodiversity. Protected Areas (PAs) are intended to conserve habitats and species. Variability in PA effectiveness and 'leakage' (here defined as displacement of deforestation) may lead to different trends in forest loss within, and adjacent to, exis...

2009
Arun Kumar

The problems of the environmental management in river basins are treated as periphery problems. Though, these areas are often included in great reserves of natural resources of the nation, their contribution to the main land is quite often in terms of forest, water, wildlife, tourism and leisure industries. Forest and forest eco-systems of north-east India in general and Manipur in particular, ...

2016
Reginald P. Webster Patrice Bouchard Jan Klimaszewski Jon D. Sweeney

1 24 Mill Stream Drive, Charters Settlement, NB, Canada E3C 1X1 2 Agriculture and Agri-Food Canada, Canadian National Collection of Insects, Arachnids and Nematodes, Ottawa, Ontario, Canada K1A 0C6 3 Natural Resources Canada, Canadian Forest Service Laurentian Forestry Centre, 1055 du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, Quebec, Canada G1V 4C7 4 Natural Resources Canada, Canadian ...

2005
RAFAEL AVILA-FLORES BROCK FENTON

We analyzed the patterns of habitat use by insectivorous bats in Mexico City, one of the largest and most populated cities of the world. We tested the hypotheses that richer patches of food, expected in more vegetated areas, have higher bat activity levels, and that fast-flying species benefit most from urbanization. We compared activity of insectivorous species and relative abundance of insect...

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