نتایج جستجو برای: and plant cover

تعداد نتایج: 16893867  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم کشاورزی و منابع طبیعی گرگان - دانشکده جنگلداری و مهندسی چوب و کاغذ 1391

درک الگوی توزیع مکانی ماکروفون خاک بدلیل اثرات آن روی فرآیندهای اکوسیستم بسیار مهم است. لیکن اطلاعات کمی در این خصوص وجود دارد. درمورد تنوع زیستی ارگانیسم ها وجانداران خاکزی که ازاجزای مهم وکلیدی درهرسیستم اکولوژیکی هستند و در بهبود حاصلخیزی خاک و تولیدات زمین وپایداری اکوسیستم ها(ازطریق فرآیندهای بیولوژیک)نقش عمده دارند تحقیقات کمی انجام شده است. این تحقیق جهت بررسی الگوی مکانی پارامترهای تنوع...

Climate is the most important factor of plants distribution in global and regional scale. Understanding the current distribution of vegetation cover and its interaction with climate regularity is important for predicting its future. In order to determine the effective climate factors in plant life-form in Polour rangelands in the Damavand summit (2400 to 4100 m above sea level), Iran, a study w...

2006
M. S. Thomsen K. McGlathery

Increases in sediment and drift algae accumulations have caused degradation of coastal lagoons worldwide. It is well known that these factors are stressors of seagrass beds, sediment fauna and coral reefs. However, little is known about the impacts on temperate hard-bottom assemblages within soft-bottom lagoons. To test if accumulations of sediment and drift algae (stress) affected recruitment ...

Journal: :محیط شناسی 0
دکترمحمد جعفری مهندس سید ابوالفضل نصراللهی دکتر فریدون سرمدیان دکتر حسین آذرنیوند

relationship between plant and sial has special importance, because it is judged about one by considering the another one. soil-plant relationship is used for range trend, range emdttton, range suitability in range species. this research, includes: the analysis of plant different types and dominant species in each type with soil factors such as percentage of lime clay depth, stone and gravel (s...

Journal: :بوم شناسی کشاورزی 0
عباداله مؤیدی شهرکی مجید جامی الاحمدی محمد علی بهدانی سهراب محمودی

in order to evaluate the effect of cover crops and mulch management on yield and yield components of safflower (carthamus tinctorius l.), a study was conducted as split-plot based on a complete randomized block design with four replications during 2008-2009. the mulch managements as main factor were consisted of three levels including incorporation of cover crops with soil, harvesting + removin...

2017
Dylan Craven Madhav P. Thakur Erin K. Cameron Lee E. Frelich Robin Beauséjour Robert B. Blair Bernd Blossey James Burtis Amy Choi Andrea Dávalos Timothy J. Fahey Nicholas A. Fisichelli Kevin Gibson I. Tanya Handa Kristine Hopfensperger Scott R. Loss Victoria Nuzzo John C. Maerz Tara Sackett Bryant C. Scharenbroch Sandy M. Smith Mark Vellend Lauren G. Umek Nico Eisenhauer

Globally, biological invasions can have strong impacts on biodiversity as well as ecosystem functioning. While less conspicuous than introduced aboveground organisms, introduced belowground organisms may have similarly strong effects. Here, we synthesize for the first time the impacts of introduced earthworms on plant diversity and community composition in North American forests. We conducted a...

Journal: :journal of rangeland science 2011
nasrin kolahchi mohsen mohseni saravi ali tavili mohammad jafari ghassem assadian

vegetation cover is the first barrier for the raindrops resulting to the interception and infiltration loss. interception as one of the main components of ecohydrology equation plays a major role in the water balance of rangelands. however, few studies have been done on the interception of rangeland plants in iran. this study was carried out to find the interception rate in astragalus parrowian...

B. Attaeian D. Akhzari M. Bashir Gonbad S. Haghighi

Water scarcity is one of the factors limiting plant growth and development. More than onethird of the global terrestrial ecosystems is located in arid and semi-arid regions. The mostimportant limiting factor for plant growth is water shortage. Drought could significantlychange the natural vegetation cover. Rainfall reduction in Iraq, Turkey and Syria hasreduced vegetation cover so that dust sto...

2008
Murat Demir Ender Makineci Beyza Sat Gungor

This study was executed to determine the plant species of herbaceous cover in a skid road subjected to soil compaction due to timber skidding in a beech (Fagus orientalis Lipsky.) stand. Our previous studies have shown that ground based timber skidding destroys the soils extremely, and degradations on ecosystem because of the timber skidding limit recovery and growth of plant cover on skid road...

Exclusion and not using of rangeland in the long term affects the composition and homogeneity of vegetation and consequently leads to the improvement of plants status. In this study, the characteristics and structural changes of the rangeland of Gonbad, Hamadan province, Iran, in 2014 (after 20 years of enclosure) were evaluated using Braun-Blanquet plot, Phytosociology and multivariate analysi...

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