نتایج جستجو برای: 30 dead trees were selected

تعداد نتایج: 3924983  

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده ادبیات و زبانهای خارجی 1390

abstract the current study set out to address the issue as to whether the implementation of portfolio assessment would give rise to iranian pre-intermediate efl learner autonomy. participants comprised 60 female in pre-intermediate level within the age range of 16-28.they were selected from among 90 language learners based on their scores on language proficiency test -key english test. then, t...

پایان نامه :0 1375

the following null hypothesis was proposed: there is no significant difference between the efl students listening comprehension development receiving pictorial cues and those receiving no cuse. to test the null hypothesis, 52 male and femal freshmen students of medicine studing at iran university of medical scinces were randomly selected from a total population of 72 students. to ensure that th...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان تهران - دانشکده زبانهای خارجی 1393

the purpose of this study was to examine the english language needs of medical students at tehran university of medical sciences . analysis of the needs took place for three groups: 320 undergraduate students, 30 postgraduate students and 20 university instructors. a triangulation approach to collect data was used in which a combination of the quantitative (using the questionnaires) and qualita...

2010
Jennifer C. Pierson Scott Mills Donald P. Christian

Fuel-reduction/forest restoration treatments that consist of thinning followed by prescribed burning are becoming increasingly important land management actions that likely affect various wildlife species. To assess potential effects on bark-gleaning birds, we compared the foraging patterns of five cavity-nesting species in thinned and burned ponderosa pine (Pinus ponderosa) forest sites and co...

2002
Timo Kurkela

Trees in three Scots pine stands seriously infected by Heterobasidion annosum were classifi ed according to their crown condition into four classes, from healthy to dead trees. After cutting the stands, the classifi cation was compared with the symptoms of annosum root rot on stump surfaces (pitched area) and with the extension of decay in the roots of excavated stumps. When dead trees were inc...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد گرمسار - پژوهشکده علوم انسانی و اجتماعی 1390

this study was an attempt to investigate and compare the effect of lexical inferencing and concept mapping on developing vocabulary retention of iranian language learners. sixty homogeneous students from different intact classes who were being taught as intermediate learners in sokhan english institute participated in this study. they were in different classes. a teacher made test as a pre-test...

2007
ROGER W. PERRY RONALD E. THILL

Little information has been published on selection of tree roosts by eastern pipistrelles (Perimyotis subflavus) in forested environments, and no radiotelemetry-based studies have been conducted on males in forested settings. Therefore, we used radiotelemetry to characterize summer roost selection by 21 male (33 roosts) and 7 female (14 roosts) eastern pipistrelles during 6 years in a forested ...

2015
Kiomars Sefidi

Dead wood and habitat tree such as fallen logs, snags, stumps and cracks and loos bark etc. are regarded as an important ecological component of forests on which many forest dwelling species depend on presence of them within forest ecosystems. Meanwhile its relation to management history in Caspian forest has gone unreported. The aim of research was to compare the amounts of dead wood and habit...

Journal: :American journal of botany 2003
Stephen C Sillett Mark G Bailey

Redwood forests contain some of the largest and most structurally complex trees on Earth. The most abundant vascular epiphyte in these forests is the fern Polypodium scouleri (Polypodiaceae). We measured dimensions of all 765 P. scouleri mats on 32 trees (27 Sequoia sempervirens, 5 Picea sitchensis). Eighteen P. scouleri mats from 11 trees were randomly selected for removal and dissection in th...

Journal: :جنگل و فرآورده های چوب 0
سهیل سهیلی اصفهانی کارشناس ارشد مهندسی منابع طبیعی، گرایش جنگل داری، دانشکدۀ منابع طبیعی ساری، ساری، ‏ایران اصغر فلاح دانشیار گروه جنگل داری، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران

in order to study the qualitative, quantitative characteristics of a pure common populus alba stand in polkalleh & a mixed stand of populus alba & populus nigra in karchegan, two 30-year-old stands were selected with a plantation interval ( spacing) of 2.5 × 1.5 m in each of which 30 pcs of 2 are samples were randomly selected. in each sample pc all the trees diameters were measured using a dia...

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