نتایج جستجو برای: oak forest

تعداد نتایج: 113572  

امیراحمدی, بهمن, ذوالفقاری, رقبه, میرزایی قره لر, محمدرضا,

In recent years, fundamental changes in the ecosystems of Zagros forest structure have occurred, including the decline of brant’s oak (Quercus bratii Lindl.) that is main species in this region. So this research intends to study trees decline in relation to sylviculture, topography, and soil characteristics. For this purpose, first, parts of forest that showed oak decline were identified by fie...

2015
Michal Wiezik Marek Svitok Adela Wieziková Martin Dovčiak Darren Ward

Global or regional environmental changes in climate or land use have been increasingly implied in shifts in boundaries (ecotones) between adjacent ecosystems such as beech or oak-dominated forests and forest-steppe ecotones that frequently co-occur near the southern range limits of deciduous forest biome in Europe. Yet, our ability to detect changes in biological communities across these ecosys...

2017
Dariusz Kubiak Piotr Osyczka

To date, the lichens Chrysothrix candelaris and Varicellaria hemisphaerica have been classified as accurate primeval lowland forest indicators. Both inhabit particularly valuable remnants of oak-hornbeam forests in Europe, but tend toward a specific kind of vicariance on a local scale. The present study was undertaken to determine habitat factors responsible for this phenomenon and verify the i...

2014
Rachel Pain

Less than 10% of Minnesota’s hardwood forests remain after heavy logging in the 19 and early 20 centuries. In order to ensure that this ecosystem continues to be a part of Minnesota’s natural history, forest managers have begun practicing active and passive restoration. The composition of a remnant forest, planted forest, and an adjacent old-field in the St. Olaf College Natural Lands, was anal...

Journal: :Applied and environmental microbiology 2004
Evelyn Hackl Sophie Zechmeister-Boltenstern Levente Bodrossy Angela Sessitsch

The diversity and composition of soil bacterial communities were compared among six Austrian natural forests, including oak-hornbeam, spruce-fir-beech, and Austrian pine forests, using terminal restriction fragment length polymorphism (T-RFLP, or TRF) analysis and sequence analysis of 16S rRNA genes. The forests studied differ greatly in soil chemical characteristics, microbial biomass, and nut...

2011
Dale R. Weigel Daniel C. Dey Chao-Ying Joanne Peng

—Oak (Quercus spp.) stump sprouts are vital to sustaining oak’s presence and long-term dominance when regenerating oak or mixed-hardwood forests in southern Indiana. A study was initiated on the Hoosier National Forest in southern Indiana in 1987 to predict the sprouting potential and dominance probability of oaks. Before clearcut harvesting, we sampled 2,188 trees of fi ve oak species and meas...

Journal: :Molecular ecology 2010
Ivan P Edwards Donald R Zak

The Agaricomycotina are a phylogenetically diverse group of fungi that includes both saprotrophic and mycorrhizal species, and that form species--rich communities in forest ecosystems. Most species are infrequently observed, and this hampers assessment of the role that environmental heterogeneity plays in determining local community composition and in driving beta-diversity. We used a combinati...

2015
Devin E. McMahon Ian S. Pearse Walter D. Koenig Eric L. Walters

Forest communities change in response to shifting climate, changing land use, and species introductions, as well as the interactions of established species. We surveyed the oak (Quercus L. spp.) community and Acorn Woodpecker (Melanerpes formicivorus (Swainson, 1827)) population within 230 ha of oak forest and savanna in central coastal California in 1979 and 2013 to assess demographic changes ...

Journal: :Tree physiology 2006
Micol Rossini Cinzia Panigada Michele Meroni Roberto Colombo

Pedunculate oak forests (Quercus robur L.) in the Ticino Regional Park, Italy, are declining as a result of insect attacks, summer droughts and air pollution. The assessment and monitoring of forest condition can provide a basis for managing and conserving forest ecosystems and thereby avoid loss of valuable natural resources. Currently, most forest assessments are limited to ground-based visua...

2008
John M. Kabrick Eric K. Zenner Daniel C. Dey David Gwaze Randy G. Jensen

The long-standing interest in regenerating oaks stimulated the development of a number of research studies during the past several decades. Most studies have focused on addressing oak regeneration problems and many of these suggested that oak regeneration failures occur where site conditions favor the establishment and growth of competing species that capture the growing space following crown r...

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