نتایج جستجو برای: vegetation density of higher than 50 cm

تعداد نتایج: 21303444  

ژورنال: علوم آب و خاک 2019

Evaluating the possible relationships between vegetation and environmental characteristics can assist managers to identify effective factors influencing plants establishment and to characterize various vegetation communities. This study was aimed to evaluate the effects of long term grazing exclusion ( more than 33 years) and the controlled grazing system (resting – rotation grazing system) on ...

2016
Lie Xiao Guo-Bin Liu Sha Xue

Soil microbial communities are very sensitive to changes in land use and are often used as indicators of soil fertility. We evaluated the microbial communities in the soils of four types of vegetation (cropland (CP), natural grassland (NG), broadleaf forest (BF) and coniferous forest (CF)) at depths of 0–10 and 10–20 cm on the Loess Plateau in China using phospholipid fatty acid (PLFA) profilin...

Journal: :جنگل و فرآورده های چوب 0
جواد اسحاقی راد دانشیار گروه جنگل داری دانشکدۀ منابع طبیعی دانشگاه ارومیه، ارومیه، ایران آمنه خانعلیزاده دانشجوی دکتری جنگل داری، دانشکدۀ منابع طبیعی دانشگاه ارومیه، ارومیه، ایران

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...

غفاری نژاد, سید علی, مؤمنی, داود,

To investigate the effects of different methods of seed bed preparation on yield of greenhouse cucumber, a two-year long experiment was conducted as a randomized complete block design with four replications in Jiroft from 2004. Different methods of seed bed preparation were as follows: 1) ridge with 20 cm height and 50 cm width and 2 plant rows with 40 cm distance, 2) furrow with 20 cm depth an...

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 ...

A. Amjad I. Ahmad

A study was conducted to standardize production and postharvest handling of lily (Lilium longifolium L. cv. Mero Star). In production trial, three plant densities viz.10, 20 and 30 cm between plants in 60 cm spaced rows and two planting depths viz.7.5 and 15 cm were compared. Increased plant growth, yield and quality was recorded when plants were grown at a close spacing of 10 cm with 15 cm pla...

The aim of this study was to investigate relationships between soil properties and plant species to determine the most effective factors separating vegetation communities in Rineh rangeland. Three stratifying variables were selected including slop, aspect and elevation. The study area was partitioned by combining these classes to generate homogenous units. 1m2 quadrates were located at sampling...

پایان نامه :0 1374

the rationale behind the present study is that particular learning strategies produce more effective results when applied together. the present study tried to investigate the efficiency of the semantic-context strategy alone with a technique called, keyword method. to clarify the point, the current study seeked to find answer to the following question: are the keyword and semantic-context metho...

Journal: :تحقیقات مهندسی کشاورزی 0
غلامرضا قهرمانیان عضو هیئت علمی بخش تحقیقات فنی و مهندسی مرکز تحقیقات کشاورزی و منابع طبیعی آذربایجان غربی علیرضا عیوضی عضو هیئت علمی بخش تحقیقات فنی و مهندسی مرکز تحقیقات کشاورزی و منابع طبیعی آذربایجان غربی امیر نورجو

the effects of soil tillage methods and residue management were studied at miandoab agriculure station during 2003-2005. the experiment design was split block with the main plots devoted to residual management strategies (burning residue, crushing residue by disk, no treatment). subplots were tillage methods (moldboard plowing to 20-25 cm in fall, moldboard plowing to 20-25 cm in spring, moldbo...

Ali Ashraf Jafari Hossein Arzani Mohammad Jafari Sedigheh Zare Kia Seyyed Akbar Javadi

This study aims to assess the effect of grazing intensity on vegetation structure, soil nutrient concentrations and soil physical properties. The study was carried out in steppe rangelands of Saveh, Markazi province, Iran. Four sites with four grazing intensities including very high, high, moderate and non-grazed with the same ecological conditions were selected. To study various vegetation and...

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