نتایج جستجو برای: forest growth

تعداد نتایج: 915181  

2004
Jeffrey P. Prestemon Joseph Buongiorno David N. Wear Jacek P. Siry

The 21”’ century continues a trend of rapid growth in both international trade of forest products and a concern for forests. These two trends are connected. Forces causing trade growth are linked to the loss of native forest resources in some countries and the accumulation of nonnative forest resources in other countries. Factors increasing trade include relaxation of trade barriers, income gro...

2015
M. Irfan Ashraf Fan-Rui Meng Charles P.-A. Bourque David A. MacLean Ben Bond-Lamberty

Global climate is changing due to increasing anthropogenic emissions of greenhouse gases. Forest managers need growth and yield models that can be used to predict future forest dynamics during the transition period of present-day forests under a changing climatic regime. In this study, we developed a forest growth and yield model that can be used to predict individual-tree growth under current ...

2006
Mike Jull

FIGURE 1. Aerial view of the Group Selection openings, Fleet Creek. Introduction Increasingly in British Columbia, forest managers are seeking to use a greater variety of silvicultural system options, and reduce reliance on clearcutting. In BC and the Pacific Northwest, the shift in forest practices in response to changing environmental and land use attitudes is well-documented (Kohm and Frankl...

2000
Shashi Kant

In the developing economies, optimal forest regimes should incorporate the socio-economic characteristics of the user groups. And, since socio-economic factors will change with time, optimal forest regimes will also follow a dynamic path. The two most important socio-economic factors are the heterogeneity of the user group with respect to forest management and the direct dependence of the user ...

Journal: :Remote Sensing 2015
Rafi Kent Jeremy A. Lindsell Gaia Vaglio Laurin Riccardo Valentini David A. Coomes

Identifying historical forest disturbances is difficult, especially in selectively logged areas. LiDAR is able to measure fine-scale variations in forest structure over multiple kilometers. We use LiDAR data from ca. 16 km2 of forest in Sierra Leone, West Africa, to discriminate areas of old-growth from areas recovering from selective logging for 23 years. We examined canopy height variation an...

Journal: :جنگل و فرآورده های چوب 0
محمود بیات دکتری جنگل داری، دانشکدۀ منابع طبیعی دانشگاه تهران، کرج، ایران منوچهر نمیرانیان استاد، دانشکدۀ منابع طبیعی دانشگاه تهران، کرج، ایران محمود زبیری استاد، دانشکدۀ منابع طبیعی دانشگاه تهران، کرج، ایران تیمو پوکالا استاد گروه جنگل داری، دانشگاه شرقی فنلاند، جوئنزو، فنلاند

hyrcanian forests are the most valuable forests in the north of iran and industrial harvesting occurs only in this area. it is a productive region near the southern coast of caspian sea. in these forests mixed beech stands mostly shown uneven-aged structure that is managed under selection system. in order to determine the priority of uneven aged method not only from an ecological view, but also...

احمدی, مرضیه, ترکمن, جواد, قدس خواه دریایی, مهرداد, معروفی اقدم, بفرین, کریم زاده, سرخوش,

Due to variances in response of different tree species in different habitats to climate changes, further studies in this field is clearly required. On the other hand, the lack of studies on chronology to evaluate the effect of solar radiation on radial growth of tree species due to lack of long term data of an important climatic variable, new approaches to determine the effect of this parameter...

قاسمی آقباش, فرهاد, ملکی, بتول,

Construction of forest roads creates certain conditions in roadside that this situation has its positive and negative effects. This study was done to evaluate the ecological effects of forest road in Amygdalusscoparia forest reserve in Dehloran, Zarin Abaad. After selecting a suitable location for sampling, three transects in the direction perpendicular to the axis of the road in both sides was...

2015
John W. Coulston David N. Wear James M. Vose

Over the past century forest regrowth in Europe and North America expanded forest carbon (C) sinks and offset C emissions but future C accumulation is uncertain. Policy makers need insights into forest C dynamics as they anticipate emissions futures and goals. We used land use and forest inventory data to estimate how forest C dynamics have changed in the southeastern United States and attribut...

2015
Rico Fischer Andreas Ensslin Gemma Rutten Markus Fischer David Schellenberger Costa Michael Kleyer Andreas Hemp Sebastian Paulick Andreas Huth

Tropical forests are carbon-dense and highly productive ecosystems. Consequently, they play an important role in the global carbon cycle. In the present study we used an individual-based forest model (FORMIND) to analyze the carbon balances of a tropical forest. The main processes of this model are tree growth, mortality, regeneration, and competition. Model parameters were calibrated using for...

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