نتایج جستجو برای: trees
تعداد نتایج: 90009 فیلتر نتایج به سال:
The formation of gall is one of the various types of vegetarianism, and gall producing insects cause stress in their hosts. The present study aimed to investigate the changes of some biochemical and photosynthetic indices due to the gall in Persian oak trees in Forests of Middle Zagros. Sampling was performed from trees infected by gall and healthy trees in Blouran forests. The results showed t...
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...
knowledge of the stand condition and the gradual replacement of tree species in different development stages and phases provide appropriate information related to the close to nature treatments. stem exclusion phase is one of the important development phases in the forest stands development. the aim of study was to analyze the characteristics of dead trees in the stem exclusion phase in the les...
Trees can improve air quality, but at the same time, pollution might put them at risk. Plane(Platanus orientalis L) and willow trees (Salix babylonicaL) are important trees in the green space of Tehran. Plane trees in Tehran have experienced early autumn in recent years due to severe air pollution. The present study, investigated some physiological traits of these trees under study to determine...
Tree marking can cause changes in forest. This study aimed to assess tree marking operation and to predict its effect on stand structure of Persian ironwood-hornbeam stands at Bahramnia forestry plan, north of Iran. Therefore 98 trees that were marked in compartment 9 of the mentioned forest in 2017 based on selection system and according to the recent laws of Forests, Range and Watershed Manag...
Dead trees protection, has a key role in structural and biogeochemical processes in forest ecosystems. Some aspects of dead tree dynamics have been carefully studied, but the kind and decay degree of dead trees and forest soil properties have not received enough attention. The aim of this research was to study the effect of a kind and decay degree of dead trees on soil mineral properties in the...
Mistletoe (Loranthus europaeus Jacq) is an evergreen bush which is considered as a semi-parasitic plant of Ilam forests and show off in late autumn and winter in the northern forest of Ilam. The aim of this study was to investigate the effect of mistletoe on some Quantitative characteristics and nutrient uptake in oak forests (Quercus brantii L.) of Bankol in Ilam Province. For this study,...
In this study we have demonstrated the variations of carbohydrates and phenolic compounds present in the leaves and stems of ‘Kinnow’ mandarin (Citrus reticulata Blanco) trees in alternate bearing cycle and the possible involvement of these compounds to flower bud formation process. The amounts of these compounds were determined in the leaves and stems of “on” and “off” trees monthly from Nov...
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 ...
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