نتایج جستجو برای: forest stands

تعداد نتایج: 123621  

2016
Matthew F. Bekker Alan H. Taylor Matthew F. BEKKER Alan H. TAYLOR

We examined tree diameter, age structure, and successional trends in 100 montane forest plots to identify the effects of variation in the return interval, severity, and extent of fires on forest structure and dynamics in the southern Cascade Range, California. We classified 100 forest plots into 8 groups based on stand structural characteristics. Median point fire return intervals were shortest...

Journal: :پژوهش های علوم و فناوری چوب و جنگل 0

classifying age classes in a large area using remotely sensed data has considerable significance for forest sustainable management. in this research, landsat etm+ data from loveh forest, dating july 2002, were analyzed to investigate the potential of this sensor for age class mapping. we applied a systematic cluster sampling method to collect field data. we used 99 plots so that contained 32 pl...

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...

2008
Miguel Navascués Brent C. Emerson

15 The endemic pine, Pinus canariensis, forms one of the main forest ecosystems in the 16 Canary Islands. In this archipelago, pine forest is a mosaic of natural stands (remnants 17 of past forest overexploitation) and artificial stands planted from the 1940’s. The 18 genetic makeup of the artificially regenerated forest is of some concern. The use of 19 reproductive material with uncontrolled ...

2009
F. N. Essono L. Coulibaly R. Fournier

This study develops a cartographic index of forest stands vigour from Ikonos imagery data. The study area located at GOUNAMITZ (New-Brunswick, Canada) consists mainly of fir, tolerant and intolerant hardwoods at mature and overmature stages. Forest inventory plots were set up in the stands; dendrometric measures (height, DBH, annual increment, etc.) were collected and used to estimate reference...

2015
Lei Yu Yujie Wang Yunqi Wang Suqi Sun Liziyuan Liu

Separating the components of soil respiration and understanding the roles of abiotic factors at a temporal scale among different forest types are critical issues in forest ecosystem carbon cycling. This study quantified the proportions of autotrophic (RA) and heterotrophic (RH) in total soil (RT) respiration using trenching and litter removal. Field studies were conducted in two typical subtrop...

2002
STEVEN A. SADER

Analysis of Thermal Infrared Multispectral Scanner data collected over H. J. Andrews experimental forest in western Oregon indicated that aspect and slope gradient had a greater effect on the thermal emission of younger reforested clearcuts than of older stands. Older forest stands ( > 25 years) with greater amounts of green biomass and dosed canopies had lower effective radiant temperatures th...

2011
JEROEN STAELENS ROBERTO GODOY

South Chilean forest ecosystems represent one of the largest areas of old-growth temperate rainforests remaining in the Southern hemisphere and have a high ecological value, but suffer from deforestation, invasion by exotic species, fragmentation, and increasing atmospheric nitrogen (N) deposition. To support sustainable forest management, more knowledge is required on nutrient cycling of these...

Journal: :Environmental entomology 2009
David W Allgood Darren A Miller Matina C Kalcounis-Rueppell

Intensive pine (Pinus spp.) management is a primary land use in the southeastern United States. In eastern North Carolina, intensively managed pine stands often occur on land previously ditched and drained. Because modification of natural vegetation and water sources are known to affect dipteran community structure, we studied effects of intensive pine management on abundance and diversity of d...

Journal: :Ecological applications : a publication of the Ecological Society of America 2012
Matthew D Powers Randall K Kolka John B Bradford Brian J Palik Shawn Fraver Martin F Jurgensen

Forests function as a major global C sink, and forest management strategies that maximize C stocks offer one possible means of mitigating the impacts of increasing anthropogenic CO2 emissions. We studied the effects of thinning, a common management technique in many forest types, on age-related trends in C stocks using a chronosequence of thinned and unmanaged red pine (Pinus resinosa) stands r...

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