نتایج جستجو برای: trees
تعداد نتایج: 90009 فیلتر نتایج به سال:
selection cutting using skidding system often causes physical damage to residual stand through felling and skidding resulting decline of bole quality and tree value. this research evaluated logging damage using skidding system on residual trees and stand regeneration in uneven aged hardwood forest of asalem, were selection cutting was practiced. in this regard, systematic sampling method was us...
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...
The ecological relationship between trees is important in the sustainable management of forests. Studying this relationship in spatial ecology, different indices are applied that are based on distance to nearest neighbor. The aim of this research was introduction of important indices based on nearest neighbor analysis and their application in the investigation of ecological relationship between...
Forest structure consider the spatial arrangement of trees characteristics such as age, size, species, gender and so on is.This study aimed to investigate the structural diversity of three one-hectare stands in the gap making phase, were studied. For this purpose, three sample plots with a one hectare area were selected in Asalem beech stands which belonged to the structural features of the gap...
Spatial pattern of trees in forests reveals how trees interact with each other and their environment. Spatial structure of trees in forest ecosystems is affected by environmental heterogeneity that leads to their heterogeneous distribution. This study was aimed to investigate the appropriate methods to analyze spatial pattern of heterogeneous wild pistachio woodlands in Zagros, Iran. A 40-ha pu...
It is so important to know about ecological characteristics of trees of a stand, in forest management. The first step to achieve this knowledge is to recognize the spatial pattern of trees. Therefore, regarding the enviro-economic importance of F. orientalis in hyrcanian forests, this study checked spatial pattern of these trees. In order to do this research, 5 one-hectare plots with homogeneo...
Some olive cultivars possess high tendency to alternate bearing, which have a minus economic effect on olive industry. The experiment was performed in an olive orchard located in Shiraz region. Monthly monitoring of concentrations of unstructured carbohydrates (glucose, fructose, sucrose, mannitol and starch), protein, nitrogen, potassium and phosphorus in leaves, branches and roots of olive tr...
Most macronutrient accumulation occurs in tree leaves and there is a strong relationship between leaf nutrient change and tree decline. The aim of this study was to investigate the changes in leaf nutrients in healthy and withered trees in the forests of Marivan and Sarvabad county in Kurdistan province. For this purpose, Garan (Marivan) with declining trees were selected as unhealthy site, whi...
Almond [Prunus dulcis (Mill.) D.A. Webb] is one of the most important cultivated fruit trees in Iran. Late frost in spring is a key limiting factor for almond productivity given that almond trees flower early in the spring in comparison with other temperate fruit trees. To decrease frost injury in “Mamaei” cultivar, this study was carried out in factorial randomized complete block design (CRBD)...
Oak mortality is one of the most important management problems in the Zagros forests and the first signs of oak mortality appear in the canopy of trees. The aim of this study was to investigate the trend of oak mortality in trees with different crown-dimensions in the forests of Baneh County (northwest of Kurdistan province). For this study, four sites in the northern slopes (Saraki and Mirhesa...
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