نتایج جستجو برای: disturbing the upper soil layers

تعداد نتایج: 16137039  

Journal: :جنگل و فرآورده های چوب 0
مقداد جورغلامی دانشکده منابع طبیعی دانشگاه تهران، دکترای جنگلداری آزاده خرمی زاده دانشگاه تهران شکوه سلطانپور گروه جنگلداری و اقتصاد جنگل، دانشکده منابع طبیعی، دانشگاه تهران

the use of heavy machinery in forestry operations such as logging has increased worldwide during the last decades. however, these machines may seriously influence the soil ecosystem as they induce rutting, disturbing the upper soil layers, and soil compaction. severe compaction of soil adversely affects the growth of plants.this study was done by using a penetration resistance experiment in a g...

پایان نامه :دانشگاه تربیت معلم - تهران - دانشکده ادبیات و علوم انسانی 1390

abstract the variables affecting the nature of reading comprehension can be classified into two general categories: reader’s variables, and text variables (alderson, 2000). despite the wave of research on vocabulary knowledge as reader’s variable, the role of this knowledge in c-test as a text-dependent test and its interaction with lexical cohesion of the test as a text feature has remained a...

D. Ci F. Qin H. Ding L. Dai T. Kang W. Song Z. Zhang,

The effects of two water regimes (well-watered condition or drought stress) on root length,root surface area and root volume were tested on two peanut genotypes (the drought-resistantvariety HuaYu 22 (HY22) and the drought-sensitive variety HuaYu 23 (HY23)), measured 101days after sowing. The roots were sampled from the upper (0–40 cm) and deeper (40–100 cm)soil layers. Root diameter was measur...

Abdolhossein Rezaipoorbaghedar Hamid Reza Azimzadeh Majid Sadeghinia Mohammad Hossein Hakimi

In order to sustainable use of rangelands, it is necessary to recognize water, soil, and vegetation cover and analyze their relationships. Physical and chemical properties of soil are effective in distribution of plant species in local area. To determine the effects of some soil properties on species distribution of Eurotia ceratoides and Stipa barbata in Baghedar summer region of Bafgh, three ...

Journal: :journal of rangeland science 2012
abdolhossein rezaipoorbaghedar mohammad hossein hakimi majid sadeghinia hamid reza azimzadeh

in order to sustainable use of rangelands, it is necessary to recognize water, soil, and vegetation cover and analyze their relationships. physical and chemical properties of soil are effective in distribution of plant species in local area. to determine the effects of some soil properties on species distribution of eurotia ceratoides and stipa barbata in baghedar summer region of bafgh, three ...

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

the present study aimed at investigating how different news agencies using the concept of legitimation/delegitimation represent the same event differently. to this end, van leeuwens (2008) legitimatory/delegitimatory framework was applied to the data gleaned from the iranian state-run news agency fars news, british state-run news agency bbc, and also american state-run news agency voa. the resu...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1392

gol-e-gohar iron ore mine of sirjan in southern part of iran is a large open pit that operates below the groundwater table and during mining operation, dewatering is required to prevent operation processes from flooding. current operation is going on by digging wells in or out of the pit and pumping to prevent flooding. as a result of the former dewatering operation a vast deep cone of depressi...

2016
Dongyan Liu Kanako Tago Masahito Hayatsu Takeshi Tokida Hidemitsu Sakai Hirofumi Nakamura Yasuhiro Usui Toshihiro Hasegawa Susumu Asakawa

Elevated concentrations of atmospheric CO2 ([CO2]) enhance the production and emission of methane in paddy fields. In the present study, the effects of elevated [CO2], elevated temperature (ET), and no nitrogen fertilization (LN) on methanogenic archaeal and methane-oxidizing bacterial community structures in a free-air CO2 enrichment (FACE) experimental paddy field were investigated by PCR-DGG...

ژورنال: علوم آب و خاک 2010
افیونی, مجید, شیرانی, حسین , حاج عباسی, محمدعلی , همت, عباس,

Tillage systems and organic manures could affect soil physical and mechanical properties. This study was conducted to investigate the impacts of two tillage systems including conventional tillage by moldboard plowing (plowing depth, 30 cm) and reduced tillage by disk plow (plowing depth, 15 cm) and three rates (0, 30 and 60 ton ha-1) of farmyard manure (FYM) on the soil penetration resistance u...

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...

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