نتایج جستجو برای: semi steppe rangelands

تعداد نتایج: 147987  

Journal: :ecopersia 2014
mahdieh ebrahim iraj rahimi pordanjani pejman tahmasebi

the present study was conducted to assess the effect of dung beetles on sheep dung removal and seed dispersal in semi steppe rangelands of shahrekord province with poor condition located in iran. therefore, the large (1 cm2) and small size (1 mm2) meshes were used and filled by sheep dung in six treatments. to evaluate the role of the insects in seeds translocation, three sizes of plastic beads...

2008
Yan Zhao Zicheng Yu Fahu Chen

Pollen data from 30 sites in arid and semi-arid regions of China were reviewed to document regional patterns of Holocene vegetation and climate change and to understand the large-scale controls on these changes. Vegetation at most sites in eastern Inner Mongolia switched between forest, forest steppe, and typical steppe, showing maximum moisture conditions before 6 ka (1 ka 1⁄4 1000 cal yr BP) ...

Journal: :مرتع و آبخیزداری 0
سپیده فاضلیان دانشجوی کارشناسی ارشد مرتع داری، دانشگاه شهرکرد پژمان طهماسبی استادیار گروه مرتع و آبخیزداری دانشکدة منابع طبیعی دانشگاه شهرکرد حمزه علی شیرمردی کارشناس ارشد پژوهش مرکز تحقیقات کشاورزی و منابع طبیعی استان چهارمحال و بختیاری اسماعیل اسدی دانشیار گروه مرتع و آبخیزداری دانشکده منابع طبیعی دانشگاه شهرکرد

endozoochory is one of the seed dispersal modes through animal’s digestive systems transmission and the increases rate germination and plant establishment. the aim of this study, investigated the relationship between seed characteristics and the passage through the digestive tract of livestock and domestic animals (cattle, sheep and goats) in the 7 species perennial grass 8 species perennial fo...

Mansour Mesdaghi, Mohammad Jankju Tahereh Sadeghi Shahrakht

In arid and semi-arid ecosystems, shrubs may act as fertility islands but theireffect may vary depending on their morphology and ecological impacts. This research wasaimed to study effect of three shrubs Scariola orientalis, Astragalus heratensis, and Rosapersica on soil properties and on the microclimate conditions (temperature, luminance, andsoil moisture) of their understory in the steppe ra...

Journal: :آب و خاک 0
جلال حیدری شجاع قربانی دشتکی فایز رئیسی پژمان طهماسبی

annual fires might change many soil physical properties in semi steppe rangeland.the objective of this study was to investigate the impact of fire on soil physical properties and soil water infiltration parameters in semi-steppe rangeland of karsanak region in chaharmahal and bakhtiari province. therefore, several sites were chosen which were affected by fire at three, two and one years prior t...

Journal: :Global change biology 2015
Martin Wiesmeier Sam Munro Frauke Barthold Markus Steffens Peter Schad Ingrid Kögel-Knabner

Organic carbon (OC) sequestration in degraded semi-arid environments by improved soil management is assumed to contribute substantially to climate change mitigation. However, information about the soil organic carbon (SOC) sequestration potential in steppe soils and their current saturation status remains unknown. In this study, we estimated the OC storage capacity of semi-arid grassland soils ...

In the rangelands of Iran, the lack of appropriate grazing management is one of the major problems ultimately leading to untimely and excessive grazing intensity of forage. Accordingly, most of the rangelands show a retrogression trend and poor conditions. In forage species, phenological stage is one of the most important criteria for range management. Bromus tomentellus species is an ...

2004
Charles Perrings Brian Walker

In previous papers we have considered the optimal mix of biodiversity in semi-arid rangelands, focusing on the steady state. This paper addresses the question of conservation in the optimal use of rangelands, where conservation is understood to mean maintenance of the system in a ‘natural’ state. We consider a rangeland that may exist in one of two states. In the ‘natural’ state, its dynamics a...

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