نتایج جستجو برای: hyrcanian ecozone

تعداد نتایج: 363  

Journal: :environmental resources research 2014
syavash kalbi asghar fallah shaban shataee

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...

Azadnejad , Saeed , Taefi Feijani , Masoud ,

Mapping of forest extent is a prerequisite to acquire quantitative and qualitative information about forests and to formulate management and conservation strategies. forest canopy density (FCD) model is one of the useful RS methods for forest mapping using satellite images. One of the most serious challenges in FCD model is the weakness in the calculation of canopy density in low density forest...

Journal: :Mycologia 2005
Lecong Zhou K L Bailey C Y Chen Mario Keri

Molecular and genetic approaches were used to evaluate the genetic relatedness among isolates of the fungus Phoma macrostoma Montagne originating from Canada and Europe and to other species in the genus Phoma. Distinct differences were observed in genetic variation among nine species of the genus Phoma. Randomly amplified polymorphic DNA (RAPD) revealed the presence of intraspecific genetic var...

Journal: :caspian journal of environmental sciences 2012
al. et e. ebrahimi

the effects of initial spacing layout on some allometric characteristics of 12-year-old quercus castaneifolia trees grown in central mazandaran, north of iran were examined. trees were planted in 5 different layouts (1?1, 1.5?1.5, 2?2.5, 2?3 and 4?4 m). tree height, diameter at breast height, natural pruning height and the survival of trees were recorded in each sample plot. tree basal area and...

Journal: :caspian journal of enviromental sciences 0

this research develops an allometric model for estimation of biomass based on the height and dbh of trees in the hyrcanian forests of iran. an accurate allometric model reduces the uncertainty of allometric equation in biomass estimation using radar images. in this study, 317 trees were selected randomly from the 4 different dominant tree species for the development of an allometric model cover...

Journal: :caspian journal of environmental sciences 2011
al. et p. panahi

chestnut-leaved oak (quercus castaneifolia c. a. mey) is one of the most important native oaks of iran distributed in the hyrcanian forests. the pure and mixed stands of it cover about 6.5% of these forests. the species represents morphological variations which have resulted in the description of several infraspecific taxa by different authors. eight taxa were recognized as subspecies and varie...

ژورنال: :مجله گیاهشناسی ایران 2010
حمید قلی زاده علیرضا نقی نژاد محمد امینی راد حسن زارع مایوان

carex humilis leyss. از تیره اویارسلام برای اولین بار از ایران و منطقه فلورا ایرانیکا گزارش می شود. این گیاه از جمله گیاهان مناطق مرتفع کوهستانی در گیلان است که در ارتباط با مطالعه اکولوژیکی این مناطق جمع آوری شده است. یادداشت های تاگزونومیکی و پراکنش این گونه ارائه شده است.

P. Salehi Shanjani

Resource sustainability requires a thorough understanding of the influence of forest management programs on the conservation of genetic diversity in tree populations. To observe how differences in forest management affect the genetic structure of Fagus orientalis Lipsky (oriental beech), we evaluated thirteen beech sites across Hyrcanian forests, based on six microsatellite loci. Significant di...

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