نتایج جستجو برای: Plant cover

تعداد نتایج: 497813  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده منابع طبیعی و علوم دریایی 1388

this research was conducted in two protect and destroy region in the middle zagros, in illam province. in order to identification of ecological species group and evaluate density of regeneration, effect of many factors such as protection, vegetation, physiographic factors, physical and chemical properties of soil in study locations were studied. to achieve these purpose number of 54 plots using...

Journal: :caspian journal of environmental sciences 2006
a. a. safari

this study was conducted to determine soil properties that correlate with the arbuscular mycorrhizal fungal (amf) spore numbers in semiarid calcareous soils of hamadan province in northwestern of iran. soil samples from six sites managed differently were collected from a 0 to 30 cm depth. the results showed that land use and management systems had a significant effect on amf spore number in soi...

Journal: :علوم گیاهان زراعی ایران 0
محمد انجیل الی دانشجوی کارشناسی ارشد دانشکدۀ کشاورزی دانشگاه زنجان علیرضا یوسفی استادیار، دانشکدۀ کشاورزی دانشگاه زنجان مجید پور یوسف استادیار، دانشکدۀ کشاورزی دانشگاه زنجان رضا فتوت استادیار، دانشکدۀ کشاورزی دانشگاه زنجان

in the absence of herbicides, cover crops play an important role for weed management in organic than in conventional farming. therefore, in order to evaluate the effects of cover crop management and plant density of buckwheat (fagopyrum esculentum) as cover crop on weed suppression, a field experiment was conducted at the research farm of university of zanjan, during the growing season of 2011....

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم کشاورزی و منابع طبیعی گرگان - دانشکده مرتع و آبخیزداری و شیلات و محیط زیست 1391

مراتع حدود نیمی از خشکی های جهان را در بر دارند و پوشش گیاهی آن در نتیجه تأثیر متقابل محیط و موجودات زنده به وجود آمده است و به عنوان یک اکوسیستم طبیعی مدیریت می شوند. علاوه بر مراتع، راه ها در عصر حاضر نیز از اجزا مهم و زیرساخت های اصلی زندگی نوین و توسعه کشورها به شمار می روند. جاده ها ساخته دست بشر هستند و جوامع گیاهی کنار جاده تحت تأثیر ساخت و ساز قرار دارند. پوشش "رودرال" به مجموعه ای از پ...

Journal: :caspian journal of environmental sciences 2011
m. jafari sh. baghbani a. tavili m. a. zare chahouki a. malekian

some chemical characteristics of root, shoot and litter of index species such as salsola rigida, artemisia sieberi and stipa barbata commonly used in rangeland development projects were evaluated and compared. chemical properties of soil under and between the above mentioned species were also studied. for this purpose, vegetation types of stipa barbata and artemisia sieberi - salsola rigida wer...

Journal: :international journal of advanced biological and biomedical research 2013
vahed kiyani

for an optimum use of natural resources in the sustainable development trend, there is a need to identify ecological resources in the shortest period of time and minimum possible cost. in this article, we aimed management ecosystem by assessment of plant covers changes at taleghan township in a twenty year period. percentage of landscape and number of patch were among the metrics that were calc...

2007
David woodlands Peterson Peter

Questions: How do fire frequency, tree canopy cover, and their interactions influence cover of grasses, forbs and understorey woody plants in oak savannas and woodlands? Location: Minnesota, USA. Methods: We measured plant functional group cover and tree canopy cover on permanent plots within a long-term prescribed fire frequency experiment and used hierarchical linear modeling to assess plant ...

جلالیان, احمد, خادمی, حسین, مومنی, مسعود, کلباسی, محمود,

The forms and dynamics of soil phosphorus can be greatly affected by land use changes, which often involve changes in vegetation cover, biomass production and nutrient cycling in the ecosystem. Present research evaluates the impact of land use change on the amount of total organic and inorganic P, labile, moderately labile and nonlabile P pools in semiarid soils of central Zagros. Samples were ...

ژورنال: علوم آب و خاک 2009
جلالیان, احمد, خادمی, حسین, مومنی, مسعود, کلباسی, محمود,

The forms and dynamics of soil phosphorus can be greatly affected by land use changes, which often involve changes in vegetation cover, biomass production and nutrient cycling in the ecosystem. Present research evaluates the impact of land use change on the amount of total organic and inorganic P, labile, moderately labile and nonlabile P pools in semiarid soils of central Zagros. Samples were ...

Journal: :journal of rangeland science 2012
seyyed ali hosseini jamshid khatir namany morteza akbarzadeh

studies on vegetation changes of rangelands under grazed and non-grazedconditions are of great importance in the range management planning programs. to determinethe change process of vegetation, this study was performed in inche shorezar site of golestanprovince for nine years (1997-2005). the vegetation parameters were measured every year inseveral fixed plots inside and adjacent of exclosures...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید