Economic and environmental logging is important for sustainable wood production in the Caspian forests, north of Iran. Predetermination of the skid trail network and directional felling is a usual recommended method to reduce logging impact. The aim of this study was evaluation of directional felling and finding factors effective on felling error. Totally 135 trees were selected randomly for di...

plane and mulberry trees play a crucial role in purifying the polluted air in tehran as a majorcity. in this research, 13 main districts of tehran city were chosen as study area. 20 completely healthy planeand mulberry species were selected in similar ecological conditions and age range. the uptake of cd and pbwas determined using spectrophotometry, whereas the chlorophyll content was measured ...

the traditional event tree analysis uses a single probability to represent each top event. however, it is unrealistic to evaluate the occurrence of each event by using a crisp value without considering the inherent uncertainty and imprecision a state has. the fuzzy set theory is universally applied to deal with this kind of phenomena. the main purpose of this study is to construct an easy metho...

capacity of garden productions in iran is such that is accounted as a country that produces thirteen garden products in the world but despite excellent condition in iran for producing garden products, natural disasters damage production of fruits in the country therefore farmers incur a loss. pistachio tree has been in danger of destruction and dryness. thus, in order to reduce loss incurred on...

the paper deals with the analysis of the external factor (solar activity, volcanic eruptions) influence on tree growth at the kola peninsula, northwestern russia. pinus sylvestris l. (scots pine) tree-ring chronologies collected nearby the northern timberline (68.63n, 33.25e) include the oldest (1445-2005 ad) living pine tree found up to date in the kola peninsula. a total of 18 living trees p...

Afforestation, as a tool to mitigate carbon emission is constrained by available land areain several countries, but Iran has the potential of plantation. In doing so, differences in soilstocks between tree species could give an indication of the effects of future managementchanges. Hence, a better understanding of tree species traits on soil properties is required topredict how changes in ecosy...

For maintaining of Zagros forests role in wild life, water and soil conservation, the suitable solutions and methods for assessing the existing conditions and planning for management of this forests should be given. To detection of suitable sampling method to study tree Diameter at Breath Height in the northern Zagros forest, Blake forest, in Baneeh region, Kurdistan province, and west of Iran ...

For maintaining of Zagros forests role in wild life, water and soil conservation, the suitable solutions and methods for assessing the existing conditions and planning for management of this forests should be given. To detection of suitable sampling method to study tree Diameter at Breath Height in the northern Zagros forest, Blake forest, in Baneeh region, Kurdistan province, and west of Iran ...

The present study was focused to examine the combined effects of climate and ultraviolet-B radiation on conifer tree-ring density. Statistical methods were employed to extract tree responses in annual ring density and to identify functional relationship in trees when the level of ultraviolet-B radiation changes regardless of climate variations. In this study, the consideration was given to the ...

the prediction of liquefaction potential of soil due to an earthquake is an essential task in civil engineering. the decision tree is a tree structure consisting of internal and terminal nodes which process the data to ultimately yield a classification. c4.5 is a known algorithm widely used to design decision trees. in this algorithm, a pruning process is carried out to solve the problem of the...