نتایج جستجو برای: mixed and natural stands
تعداد نتایج: 16917246 فیلتر نتایج به سال:
knowing and conducting studies on size characters of trees is essential for assessing the tree volumeand/or other statistical parameters and also forest management. the characteristics of 529 treesincluding diameter at breast height (dbh) and total height were measured in an even-aged fraxinusstand for two periods from 2005 to 2012 in chelir district, a part of experimental kheyrud forest.resul...
burnout is a response to the chronic work stress which is prevalent mostly among the people who do people job, like teaching. the purpose of this study was to develop a valid and reliable instrument that can measure burnout in foreign language teachers. although some widely used instruments were developed before which measured burnout in teachers, a specific instrument which include specific sy...
1 The patterns of ectomycorrhizal (ECM) host specificity between understorey and canopy trees were investigated in three mixed evergreen forest stands in northern coastal California. ECM root tips from the dominant canopy ( Pseudotsuga menziesii ) and understorey ( Lithocarpus densiflora ) trees were sampled from 18 soil cores (six per stand) and identified using molecular techniques (PCR, RFLP...
Objectives: After age of 65, annually 10 percent of older adults> loss their independent in one or more daily task. Because of decreasing changes in neuromuscular system that is important factor in loss the balance and walking ability in this group of people. In according to these sentences, the aim of this research was to the comparison of mental, physical and mixed practices on static and dyn...
The effect of tree diversity on productivity in subtropical forests in China is poorly understood. We investigated the biomasses of trees, understory vegetation, coarse roots, and fine roots with varying proportions of Pinus massoniana, mixed with other tree species in stands of the same age, to examine the effects of tree diversity. With an increase of P. massoniana proportion, the tree and un...
Primary cavity-nesting birds play a critical role in forest ecosystems by excavating cavities later used by other birds and mammals as nesting or roosting sites. Several species of cavity-nesting birds are non-migratory residents and consequently subject to winter conditions. We conducted winter bird counts from 1998 to 2000 to examine the abundance and habitat association of cavity-nesting bir...
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...
WHAT IS ENTREPRENEURSHIP? The Merriam-Webster Dictionary definition of entrepreneur is “one who organizes, manages, and assumes the risks of a business or enterprise.” Each of these words is important. Entrepreneurship occurs in a business context, meaning the objective is to sell a product or service and make a profit. In business, risk is associated with uncertainty, which most commonly arise...
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