نتایج جستجو برای: species mingling and dbh dimension indices for elm in studied forest were accounted for 0.54

تعداد نتایج: 23342297  

Journal: :محیط شناسی 0
وحید علی جانی دانشکدة منابع طبیعی دانشگاه تهران ، دانشجوی کارشناسی ارشد جنگلداری و اقتصاد جنگل جهانگیر فقهی دانشکدة منابع طبیعی دانشگاه تهران ، دانشیار جنگلداری و اقتصاد جنگل

elm (ulmus glabra hudson) is one of the most valuable species which distribute all over the caspian forests. nowadays, elm is considered an endangered species due to intensive human activities and outbreak of dutch elm disease over the last few decades. to suitable management of elm, there is need to have indices which describe; current structure and its changes across the time. this study besi...

Journal: :محیط زیست طبیعی 0
وحید علی جانی دانشجوی کارشناسی ارشد گروه جنگلداری و اقتصاد جنگل دانشکده منابع طبیعی دانشگاه تهران، ایران جهانگیر فقهی دانشیار گروه جنگلداری و اقتصاد جنگل دانشکده منابع طبیعی دانشگاه تهران، ایران محمود زبیری استاد گروه جنگلداری و اقتصاد جنگل دانشکده منابع طبیعی دانشگاه تهران، ایران محمدرضا مروی مهاجر استاد گروه جنگلداری و اقتصاد جنگل دانشکده منابع طبیعی دانشگاه تهران، ایران

quantifying spatial structure is one of the most important components, describing natural ecosystems and their biodiversity. in this study, a set of indices and functions related to spatial structure using 102 established plots with an area of 1000 m2 were presented. to achieve spatial structure of carpinus-fagus type, a set of indices (clark & evans, uniform angle, shannon-wiener, mingling and...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز 1381

‏‎the community dynamics of aquatic coleoptera(insecta)in one of the spring-stream habitats of bammo national park in fars province called cheshmeh-ye-ghanbari is studied as a pilot project and model for acquaintance with and furthering the biodiversity studies on fauna of iran. sixteen species-populations out of nineteen of this community were already identified for their taxonomy and for thei...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد یزد - دانشکده شیمی 1392

in this study, a simple, rapid and selective method was developed for the determination of dexamethasone. the proposed method is based on inhibitory effect of dexamethasone on the oxidation of orange-g by bromate in sulfuric acid media. the reaction was followed spectrophotometrically at 478.5 nm (?max). under optimum experimental conditions, (72.6 ?mol l-1 of orange-g, 0.76 mol l-1 of h2so4, 0...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده زیست شناسی 1388

126 abstract: in this research we studied the effects of cyclic hydration and dehydration of cysts of artemia urmiana and artemia parthenogenetica on the hatching percentage, survival and growth. the experiment was carried out in 3 treatments (1-3 hydration/dehydration cycles) with 3 replicates for each treatment. later effects of cold preservation at -20°c during three time periods were ...

زبیری , محمود, علی‌جانی, وحید, فقهی, جهانگیر, مروی مهاجر, محمدرضا,

To implement correct management of forest ecosystems, enough information in relation to the structures of tree species is necessary. In this study, the structures of trees species in Fagus, Fagus-Carpinus, Carpinus-Fagus and Carpinus-Quercus types were investigated and compared in Hyrcanian forest. The data used in this study was collected from 239 plots with an area of 1000 m2 in Gorazbon dist...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اصفهان - دانشکده علوم 1389

this research concentrates on the lithostratigraphy, biostratigraphy, microfacies and sedimentary environment of the asmari and gachsaran formations at southwest firuzabad. the thickness of the studied section in all 608.95 meters that 220.8 meters belong to the asmari formation and 387.95 meters belong to the gachsaran formation (champe and mol members). in the study area, the asmari formation...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده علوم 1376

saluk mount is selected for devonian biostratigraphy. this area located at southwest of bojnurd. in this study three sections are selected and two sections, chahar-borj and tabar sections with a thickness of 650 m, which consist mainly of calcareous sediments was studied in detailed but third section, qelli section, with a thickness of about 450m which consist mainly of sandstone and evaporates...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this thesis, we exploit a simple and suitable method for immobilization of copper(ii) complex of 4?-phenyl-terpyridine on activated multi-walled carbon nanotubes [amwcnts-o-cu(ii)-phtpy]. this nanostructure was characterized by various physico-chemical techniques. to ensure the efficiency and fidelity of copper species, the implementation of three-component strategies in click-chemistry all...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1391

1. to determine whether difference in birth body mass influenced growth performance in pipistrellus kuhlii we studied a total of 12 captive-born neonates. bats were assigned to two body mass groups: light birth body mass (lbw: 0.89 ± 0.05, n=8) and heavy birth body mass (hbw: 1.35 ± 0.08, n=4). heavier body mass at birth was associated with rapid postnatal growth (body mass and forearm length) ...

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