نتایج جستجو برای: oak forest

تعداد نتایج: 113572  

Oak decline is an eminent factor, which has a significant role in degradation and change in Zagros forests. The goal of present study was to assess the crown surface area of oak trees in Sarableh forests, Ilam province. For this purpose, permanent sample plots were used. Eighty sample plots with 10 Ar area were applied based on systematic-random method in a 150×200 survey network in 120 ha. The...

Journal: :جنگل و فرآورده های چوب 0
فریده امیدوار حسینی دانشجوی کارشناسی ارشد رشتۀ جنگلداری، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران، تهران، ایران رضا اخوان استادیار پژوهش، مؤسسۀ تحقیقات جنگل ها و مراتع کشور، تهران، ایران هادی کیادلیری استادیار گروه جنگلداری، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات، تهران، ایران اسداله متاجی دانشیار گروه جنگلداری، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات، تهران، ایران

one of the most visible aspects of a forest stand structure is the spatial patterns of trees. competition affects on forest structure and its understanding is important, when the purpose of forest management is to imitate the dynamic of natural ecosystems. for this purpose, an unmanaged intact forest was selected with 26 hectares area. all chestnut leaf oak (quercus castaneifolia) trees with a ...

2013
Wen J. Wang Hong S. He Martin A. Spetich Stephen R. Shifley Frank R. Thompson III Jacob S. Fraser

Oak decline is a process induced by complex interactions of predisposing factors, inciting factors, and contributing factors operating at tree, stand, and landscape scales. It has greatly altered species composition and stand structure in affected areas. Thinning, clearcutting, and group selection are widely adopted harvest alternatives for reducing forest vulnerability to oak decline by removi...

2016
Tomasz Durak Roma Durak

A significant loss of biodiversity resulting from human activity has caused biotic homogenisation to become the dominant process shaping forest communities. In this paper, we present a rare case of biotic differentiation in European temperate deciduous forest herb layer vegetation. The process is occurring in nutrient poor oak-hornbeam forests in mountain areas (Polish Eastern Carpathians, Cent...

2011
Emile S. Gardiner Daniel C. Dey John A. Stanturf Brian Roy Lockhart

The lowlands associated with the Mississippi River and its tributaries historically supported extensive broadleaf forests that were particularly rich in oak (Quercus spp.) species. Beginning in the 1700s, deforestation for agriculture substantially reduced the extent of the original forest, and fragmented the remainder into small parcels. More recently, declines in agricultural commodity prices...

2004
Michael A. Steele Peter Smallwood William B. Terzaghi John E. Carlson Thomas Contreras Amy McEuen

INTRODUCTION Although oaks dominate many forest ecosystems worldwide (Barnes and others 1998), several aspects of oak ecology remain poorly understood including oak regeneration and masting (McShea and Healy 2001). Animals that eat and disperse acorns, such as squirrels, mice, and jays may play a pivotal role in oak forest dynamics (Jones and others 1998, Ostfeld and others 1996), influencing r...

Journal: :Tree physiology 2008
Julian L Hadley Paul S Kuzeja Michael J Daley Nathan G Phillips Thomas Mulcahy Safina Singh

Water use and carbon exchange of a red oak-dominated (Quercus rubra L.) forest and an eastern hemlock-dominated (Tsuga canadensis L.) forest, each located within the Harvard Forest in north-central Massachusetts, were measured for 2 years by the eddy flux method. Water use by the red oak forest reached 4 mm day(-1), compared to a maximum of 2 mm day(-1) by the eastern hemlock forest. Maximal ca...

Journal: :جنگل و فرآورده های چوب 0
جلیل کرمی دانشگاه علوم کشاورزی و منابع طبیعی گرگان محمد رضا کاوسی دانشگاه علوم کشاورزی و منابع طبیعی گرگان منوچهر بابانژاد دانشگاه گلستان

evaluating the population density and spatial pattern of infected trees are one of the important criteria for selecting the management method and epidemiology of forest diseases. this study aimed at assessing the damage intensity and spatial-temporal mortality patterns of oak in qoroq forest park, golestan province. the health of oak trees was evaluated in seven transects by using quarter-point...

2012
Zhaofei Fan Xiuli Fan Michael K. Crosby W. Keith Moser Martin A. Spetich Stephen R. Shifley

At the forest landscape/region level, based on annual Forest Inventory and Analysis plot data from 1999 to 2010, oak decline and mortality trends for major oak species (groups) were examined in the Ozark Highlands of Arkansas and Missouri. Oak decline has elevated cumulative mortality of red oak species to between 11 and 15 percent in terms of relative density and basal area of standing dead oa...

2008
Itziar R. Urbieta Miguel A. Zavala Teodoro Marañón

Aims Both human and non-human determinants have shaped Mediterranean forest structure over the last few millennia. The effects of recent human activities on forest composition, however, remain poorly understood. We quantified changes in forest composition during the past century in the mixed forests of Quercus suber (cork oak) and Q. canariensis (Algerian oak), and explored the effects of fores...

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