نتایج جستجو برای: hyrcanain forests

تعداد نتایج: 39403  

2002
Paul V. A. Fine PAUL V. A. FINE

Current research efforts to understand the relative invasibility of different plant communities have mostly ignored tropical forests. Only a few studies have treated invasive species in tropical forests, and recent worldwide analyses have not provided clear predictions concerning the relative invasibility of tropical forests. In this review, the extent to which exotic species have invaded tropi...

Journal: :Revista de biologia tropical 2012
Victor P Zwiener Jochen H Bihn Márcia C M Marques

Animal-plant interactions are important for the recovery of diversity and processes in secondary forests, which increasingly dominate the tropical landscape. We used a combination of observational and experimental approaches to study the interactions of ants with diaspores across a successional gradient of forests in Southern Brazil, from August 2007 to April 2008. In addition to diaspore remov...

Journal: :جنگل و فرآورده های چوب 0
فرخ پورشکوری اله ده دانشجوی دکتری جنگل‏داری، دانشکدۀ منابع طبیعی دانشگاه تهران، کرج، ایران علی اصغر درویش صفت استاد دانشکدۀ منابع طبیعی دانشگاه تهران، کرج، ایران فرهاد صمدزادگان استاد دانشکدۀ فنی دانشگاه تهران، تهران، ایران پدرام عطارد دانشیار دانشکدۀ منابع طبیعی دانشگاه تهران، کرج، ایران

moderate resolution imaging spectroradiometer (modis) have been widely used for active fire detection in the world as the specific channels used for the fire detection have made the modis images applicable. the main objective was to explore the capability of modis images for active fire detection in the zagross forests using the modis contextual algorithm. the study was performed in the marivan...

2009
Ariel E. Lugo

In 1966 Eugene P. Odum delivered a speech before the Ecological Society of America that transformed the way ecologists looked at succession. His comparison of mature and successional systems lead ecologists to place secondary forests in an inferior position relative to mature ones to the point that today, prominent tropical biologists argue for and against the conservation value of secondary fo...

2012
Joachim Krug Michael Koehl Dierk Kownatzki

UNLABELLED BACKGROUND Unmanaged or old-growth forests are of paramount importance for carbon sequestration and thus for the mitigation of climate change among further implications, e.g. biodiversity aspects. Still, the importance of those forests for climate change mitigation compared to managed forests is under controversial debate. We evaluate the adequacy of referring to CO2 flux measurem...

2007
Luohui Liang Sachiko Kuwahara

Currently, forests cover about one-third of the world’s land area, just under 4 billion hectares (ha) (FAO, 2006a). It is estimated that 70% of the world’s forests are natural (self-generating), 20% semi-natural (regeneration with some degree of human intervention), 10% anthropogenic (established or significantly transformed by humans) (MA, 2005). 75% of the world’s forests are located in two b...

2002

Indonesia is home to some of the most magnificent tropical forests in the world. In extent, they rank third behind Brazil and the Democratic Republic of Congo (formerly Zaire), and their biological richness is unique. The major forest types of Indonesia range from evergreen lowland dipterocarp forests in Sumatra and Kalimantan to seasonal monsoon forests and savanna grasslands in Nusa Tenggara ...

2007
Pengyu Zhu Yaoqi Zhang

Extensive economic investigations have shown a variety of benefits derived from urban forests, but study on demand for urban forests remains limited. This study investigates the impact of selected potential factors on the demand for urban forests at the city level. An empirical economic model is used to examine and estimate the demand for urban forests in all cities with population over 100,000...

2010
anessa L. Fox Charlotte P. Buehler Chad M. Byers Summer E. Drake

Within the eastern deciduous forest region, forest composition varies, with some areas dominated by a mix of oaks (Quercus spp.) and other areas dominated by a mix of sugar maple (Acer saccharum) and other tree species. Prescribed fire is being used on an experimental basis to assess its effectiveness in restoring and maintaining oak-dominated forests. Maple-dominated forests are susceptible to...

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...

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