نتایج جستجو برای: oak forest

تعداد نتایج: 113572  

Journal: :Tree physiology 2008
William C Parker Daniel C Dey

A field experiment was established in a second-growth hardwood forest dominated by red oak (Quercus rubra L.) to examine the effects of shelterwood overstory density on leaf gas exchange and seedling water status of planted red oak, naturally regenerated red oak and sugar maple (Acer saccharum Marsh.) seedlings during the first growing season following harvest. Canopy cover of uncut control sta...

2009
D. ANDREW SCOTT MICHAEL G. MESSINA

—Past management practices have changed much of the native mixed pinehardwood forests on upland alluvial terraces of the western Gulf Coastal Plain to either pine monocultures or hardwood (angiosperm) stands. Changes in dominant tree species can alter soil chemical, biological, and physical properties and processes, thereby changing soil attributes, and ultimately, soil functions. Restoring the...

Journal: :Molecular ecology 2005
John F Walker Orson K Miller Jonathan L Horton

Diversity of ectotrophic mycobionts on outplanted seedlings of two oak species (Quercus rubra and Quercus prinus) was estimated at two sites in mature mixed forests in the southern Appalachian Mountains by sequencing nuclear 5.8S rRNA genes and the flanking internal transcribed spacer regions I and II (ITS). The seedlings captured a high diversity of mycorrhizal ITS-types and late-stage fungi w...

اعظمی, ایاد, حسینی, احمد,

This study was conducted in oak forests of Ilam province in order to evaluate the morphological characteristics of old trees including diameter at breast height, trunk height, whole tree height, minimum and maximum crown diameter, crown health, crown vitality, crown symmetry, health and form of the trunk, Was investigated. Selection of old trees was performed based on the criteria of DBH and wi...

2011
Tomáš Hlásny Zoltán Barcza Marek Fabrika Borbála Balázs Galina Churkina Jozef Pajtík Róbert Sedmák Marek Turčáni

We analysed climate change impacts on the growth and natural mortality of forest tree species and forest carbon (C) balance along an elevation gradient extending from the Pannonian lowland to the West Carpathian Mountains (Central Europe). Norway spruce Picea abies, European beech Fagus sylvatica, and oak Quercus sp. were investigated for 2 future time periods: 2021–2050 and 2071–2100. The peri...

Journal: :caspian journal of environmental sciences 2013
p. panahi m. pourhashemi m. zandebasiri

acorn production plays a fundamental role in the organization and dynamics of oak forest ecosystems. regarding acorn importance, visual survey methods have been used to estimate acorn production of oak species throughout the world. in this study, the mast indices of brant`s oak (quercus brantii lindl.) were determined in a section of northern zagros forests, almost 36 ha area, near baneh, kurdi...

Journal: :جنگل و فرآورده های چوب 0
سید یوسف عرفانی فرد استادیار، بخش مدیریت مناطق بیابانی، دانشکده کشاورزی، دانشگاه شیراز، شیراز، ایران حمید سلیمانی دانشجوی کارشناسی ارشد، بخش مدیریت مناطق بیابانی، دانشکدة کشاورزی، دانشگاه شیراز، شیراز، ایران

diameter is such a notable characteristic in forest inventory that it is important to have a suitablemethod of its measurement, especially in coppice trees. this seems more important in zagros foreststhat most of them are covered with coppice trees. so this research was aimed to find an efficientmethod in studying the diameter at root collar (drc) of persian oak coppice trees as the mostimporta...

Journal: :Proceedings. Biological sciences 2002
Nathalie Pettorelli Jean-Michel Gaillard Guy Van Laere Patrick Duncan Petter Kjellander Olof Liberg Daniel Delorme Daniel Maillard

Body mass is a key determinant of fitness components in many organisms, and adult mass varies considerably among individuals within populations. These variations have several causes, involve temporal and spatial factors, and are not yet well understood. We use long-term data from 20 roe deer cohorts (1977-96) in a 2600 ha study area (Chizé, western France) with two habitats contrasting in quali...

2007
Charles W. Lafon John D. Waldron David M. Cairns Maria D. Tchakerian Robert N. Coulson Kier D. Klepzig

We used LANDIS, a model of forest disturbance and succession, to simulate successional dynamics of forests in the southern Appalachian Mountains. The simulated environments are based on the Great Smoky Mountains landscapes studied by Whittaker. We focused on the consequences of two contrasting disturbance regimes—fire exclusion versus frequent burning—for the Yellow pine (Pinus L., subgenus Dip...

2007
Brian C. McCarthy Scott A. Robison

Understory light environments were evaluated in four mixed-oak forests in southern Ohio using hemispherical photography. Within each forest, plots were divided into nine treatment combinations based on three pretreatment fire categories and three Integrated Moisture Index (IMI) categories. For each of 108 photographs we determined the percentage of open sky, direct beam, and diffuse radiation; ...

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