نتایج جستجو برای: plant cover

تعداد نتایج: 497813  

Journal: :Conservation biology : the journal of the Society for Conservation Biology 2009
Victoria A Nuzzo John C Maerz Bernd Blossey

Identification of factors that drive changes in plant community structure and contribute to decline and endangerment of native plant species is essential to the development of appropriate management strategies. Introduced species are assumed to be driving causes of shifts in native plant communities, but unequivocal evidence supporting this view is frequently lacking. We measured native vegetat...

Jamshid Khatir Namany Morteza Akbarzadeh, Seyyed Ali Hosseini

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...

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Gully erosion is one of the most significant erosion types. This type of erosion is one of the most important sources of sediment in different regions of the world. Gullies often have different dimensions and complex characteristics and these characteristics may affect the distribution of vegetation. Topographic characteristics of gullies provide complex ecosystem for vegetation establishment. ...

Journal: :مرتع و آبخیزداری 0
مریم آذرخشی استادیار دانشگاه تربت‏ حیدریه، دانشکدة کشاورزی و منابع طبیعی، ایران محمد مهدوی استاد دانشگاه تهران، دانشکدة منابع طبیعی، ایران حسن احمدی استاد دانشگاه تهران، دانشکدة منابع طبیعی، ایران حسین ارزانی استاد دانشگاه تهران، دانشکدة منابع طبیعی، ایران جلیل فرزادمهر استادیار دانشگاه تربت‏ حیدریه، دانشکدة کشاورزی و منابع طبیعی، ایران

plants cover composition, condition, trend, production, and grazing capacity of the rangeland change annually. in this research, the role of temporal rainfall distribution on rangeland production was assessed. this research had down in the rangelands of ilam (with semiarid to semi humid climate) and qom and markazi (with arid to semiarid climate) provinces. by attention on plant cover maps in e...

Journal: :مرتع و آبخیزداری 0
ولی الله رئوفی راد دانشجوی کارشناسی ارشد مرتعداری دانشگاه شهرکرد عطاالله ابراهیمی استادیار دانشکدة کشاورزی دانشگاه شهرکرد حسین ارزانی استاد دانشکدة منابع طبیعی دانشگاه تهران زهرا شجاعی اسعدیه استادیار دانشکدة کشاورزی دانشگاه شهرکرد

palatability includes plants physical and chemical property that encourages an animal selecta plant for grazing. this study is an attempt for intruducing an indicator for determining thepalatability of rangeland plants. to do this, the relationship between palatability and foragequality of rangeland plants in karsanak rangelands of the chaharmahal-va-bakhtiari provincewas studied. first, plant ...

2018
Kristine M Averill David A Mortensen Erica A H Smithwick Susan Kalisz William J McShea Norman A Bourg John D Parker Alejandro A Royo Marc D Abrams David K Apsley Bernd Blossey Douglas H Boucher Kai L Caraher Antonio DiTommaso Sarah E Johnson Robert Masson Victoria A Nuzzo

Herbivores can profoundly influence plant species assembly, including plant invasion, and resulting community composition. Population increases of native herbivores, e.g. white-tailed deer (Odocoileus virginianus), combined with burgeoning plant invasions raise concerns for native plant diversity and forest regeneration. While individual researchers typically test for the impact of deer on plan...

Journal: :محیط زیست طبیعی 0
رضا تمرتاش دانشگاه علوم کشاورزی و منابع طبیعی ساری، ایران مائده یوسفیان دانشگاه آزاد اسلامی واحد نور، ایران سیده خدیجه مهدوی دانشگاه آزاد اسلامی واحد نور، ایران محمد مهدوی دانشگاه آزاد اسلامی واحد نور، ایران

nowadays green house gases such as carbon have the most effect on global climate changes that can be decreased by plant and soil carbon sequestration of rangelands. livestock grazing has high potential to decrease or increase carbon storage. so this research investigated the effects of enclosure on plant carbon storage in rangeland of enclosure (shah tappeh-chah mahmood) and no enclosure (chiro...

خواجه‌ الدین, سیدجمال‌ الدین,

Plant communities of the Kolah-Ghazi National Park have been studied. The park with a wide diversity of fauna and flora species is located 36 Km south of Isfahan. 214 plant species were collected for the purposes of this study. Plant communities of the park are of an aridland vegetation type. Minimal areas of the plant communities were determined using nested plots technique. After studying the...

ژورنال: علوم آب و خاک 2000
خواجه‌ الدین, سیدجمال‌ الدین,

Plant communities of the Kolah-Ghazi National Park have been studied. The park with a wide diversity of fauna and flora species is located 36 Km south of Isfahan. 214 plant species were collected for the purposes of this study. Plant communities of the park are of an aridland vegetation type. Minimal areas of the plant communities were determined using nested plots technique. After studying t...

Journal: :مرتع و آبخیزداری 0
محسن نقیلو کارشناس دانشکده منابع طبیعی، دانشگاه تهران، ایران محمد جعفری استاد دانشکده منابع طبیعی، دانشگاه تهران، ایران محمد طهمورث 3 کارشناس ارشد آبخیزداری، ایران اصغر کهندل استادیار جهاد دانشگاهی واحد تهران، ایران فریناز همدانیان 5 فارغ التحصیل کارشناس ارشد مرتعداری، ایران

the purpose of this research was to investigate the relationship between vegetation cover and soil characteristics in order to determine the most important soil factors which affect on quantitative variations and types of vegetation cover in the study area. the study area is located in west of tehran province and southeast of hashtgerd, next to najm-abad village. after field studies, the index ...

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