نتایج جستجو برای: forest
تعداد نتایج: 106136 فیلتر نتایج به سال:
the aim of this research was to measure the relative efficiency of forest management plans in north of iran. in order to fulfill the research, data of 12 forest management plans were collected from the financial balance sheets of shafaroud forest company during a ten years period. first of all, basic data envelopment analysis (dea) models (bcc and ccr) were used to determine the efficiency. the...
one of the indicators of management and sustainability control of forest resources is the definition deforestation and degradation types. these factors hazard quantitative and qualitative of the iranian forests. in this study with integrated approach, different forms of forest degradation identified in the forest areas with a reviews of library resources and then investigation the degree of sta...
Forest future depends on forest stands regeneration. Soil is one of the principal capitals in the forest area. It is important to minimize damages to the forest ecosystem during logging operation. In forestry and forest management, it is significant to know the effect of forest logging damages on regeneration, sapling and soil compaction. This study was carried out in Asalem Beech forest area, ...
Zagros forest as a widest forests of Iran, has a special place on economical development and maintain the stability of water and soil. In order to apporopriate planning for this forest information about forest extend during past, present and future is necessary. The present research was conducted to determine the forest area reduction, during 1955 to 1997, Modeling possibility forest exten...
Forest future depends on forest stands regeneration. Soil is one of the principal capitals in the forest area. It is important to minimize damages to the forest ecosystem during logging operation. In forestry and forest management, it is significant to know the effect of forest logging damages on regeneration, sapling and soil compaction. This study was carried out in Asalem Beech forest area, ...
the zagros forests (west of iran) have been highly exploited in recent decades by human impacts. easy access, abundance and variety of valuable forest yields have led to population growth density, creation of new residential areas and deforestation activities. in order to determinate the distribution and rate of deforestation from 1995 to 2006 by using the satellite imagery (irs-1c and landsat...
TThe forest plantation strategy is to do with the identification of the most appropriate zones and the areas that are most suitable for different species. However, the success of this strategy requires the precise determination of the species ecological demands and the evaluation of the land before the establishment of the plantation. The purpose of this study is to assess the ecological capabi...
Forest types mapping, is one of the most necessary elements in the forest management and silviculture treatments. Traditional methods such as field surveys are almost time-consuming and cost-intensive. Improvements in remote sensing data sources and classification –estimation methods are preparing new opportunities for obtaining more accurate forest biophysical attributes maps. This research co...
estimation and mapping of forest resources are preconditions for management, planning and research. in this study, we applied kriging interpolation of geostatistics for estimation and mapping of forest stock at-tributes in a natural, uneven-aged, unmanaged forest in the caspian region of northern iran. the site of the study has an area of 516 ha and an elevation that ranges from 1100 to 1450 m ...
the effects of traffic frequency and skid trail slope on dry bulk density, litter mass and rutting are examined. treatments included a combination of four different traffic frequencies (3, 7, 14, and 20 passes of a rubber skidder) and three levels of slope ( 20%.) the results showed that dry bulk density, rut depth and soil displacement increased with the increase of traffic frequency and slope...
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