نتایج جستجو برای: and forest
تعداد نتایج: 16850233 فیلتر نتایج به سال:
Regeneration and forest durability guarantee is one of the most important aspects of forest sustainability and it should be placed in forest plans priority. To compare regeneration in the two grazed and non-grazed forest, Baghe-shady forest located in Khatam city (it has the preservative regions that they are 20 years old), Yazd province, Central of Iran was selected. For this purpose, 60 sampl...
this study was done to investigation forest cover changes in the mazandaran province in topographic zones. for doing that in the first matched topographic zones and land-use map. after that distribution of forest cover was investigated in plain, lowland, middle land and high land. forest cover changes analyzed in a period of 132 years since the beginning of the destructive activities in the for...
The aim of this study was to detect change of the forest area in the north of Iran between 1994 and 2001. The study area was covered by a 1:25000 topographic map (about 15000 ha) in Babol forests. The forest map of 1994 was extracted from 1:25000 topographic digital map. Landsat 7 ETM+ image dated July 30, 2001 was analyzed to produce the forest map for the end of the period. Since the evaluati...
Estimating the amount of variation due to spatial dependence at different scales provides a basis for designing effective experiments. Accurate knowledge of spatial structures is needed to inform silvicultural guidelines and management decisions for long term sustainability of forests. Furthermore, geostatistics is a useful tool to describe and draw map the spatial variability and estimation o...
In the high forests which managing with close-to-nature silvicultural method, the future of forests depends on the stable establishment of saplings planted in the gaps; hence, the current study was done by selection sampling method with the aim of qualitative and quantitative investigation of natural regeneration based on the gap area in two different beech (Fagus orientalis Lipsky) forests: pu...
recognition equal units and segregation them and upshot planning per units most basic method for management forest units. aim this study presentation and comparison classification and regression tree (cart) and random forest (rf) algorithm for forest type mapping using aster satellite data in district one didactic and research forest's darabkola. in start using inventory network 500* 350 m...
asthma and atopic dermatitis are common allergic diseases, and their prevalence has increased in urban children. recently, it is becoming understood that forest environment has favorable health effects in patients with chronic diseases. to investigate favorable clinical and immunologic effects of forest, we examined changes in clinical symptoms, indirect airway inflammatory marker, and serum ch...
this study was performed in order to investigate the changes in vegetation and soil properties in compartment no.317 (managed forest) and no.318 (control forest) of jamand district of golband forest in mazandaran (noshahr). for this purpose, random-systematic sampling method with regular grid of 100×200 m was used to locate samples. the plot size was 400 m2 considering to tree and shrub species...
proper forest management needs quantitative and precise estimates of forest stands characteristics. remotely sensed imageries, due to accurate and broad spatial information, has become a cost-effective tool in forest management. classification of forest attributes and generation of thematic maps are among the common applications of remote sensing. the objective of this study was to optimize the...
land use change may influence many natural phenomena and ecological processes, including runoff, soil erosion, sedimentation and soil conditions. decreasing of forest area in the north of iran is one of the critical problems in recent years. the aims of this study are to detect land use changes between 1967 to 2002 using satellite images of land sat 7 etm+ (2002), aerial photos and digital topo...
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