نتایج جستجو برای: so that steppe

تعداد نتایج: 6551507  

Journal: :Journal of Graduate Medical Education 2013

2016
Jian Sun

31 Although the relationship between the aboveground net primary production (ANPP) and species 32 diversity (SR) have been widely reported, there is considerable disagreement about the fitting 33 patterns of SR–ANPP, which has been variously described as ‘positive’, ‘negative’, ‘unimodal’, 34 ‘U-shaped’ and so on. Not surprisingly, the effect-factors including precipitation, aridity index and 3...

2012
Michael D. Frachetti

In this article I present a new archaeological synthesis concerning the earliest formation of mobile pastoralist economies across central Eurasia. I argue that Eurasian steppe pastoralism developed along distinct local trajectories in the western, central, and (south)eastern steppe, sparking the development of regional networks of interaction in the late fourth and third millennia BC. The “Inne...

2018
Xing Wang Xinguo Yang Lei Wang Lin Chen Naiping Song Junlong Gu Yi Xue

Excluding grazers is one of most efficient ways to restore degraded grasslands in desert-steppe communities, but may negatively affect the recovery of plant species diversity. However, diversity differences between grazed and fenced grasslands in desert-steppe are poorly known. In a Stipa breviflora desert steppe community in Northern China, we established six plots to examine spatial patterns ...

2009
Jonathan D. Bates Edward C. Rhodes Kirk W. Davies Robert Sharp

Prescribed fire in rangeland ecosystems is applied for a variety of management objectives, including enhancing productivity of forage species for domestic livestock. In the big sagebrush (Artemisia tridentata Nutt.) steppe of the western United States, fire has been a natural and prescribed disturbance, temporarily shifting vegetation from shrub–grass codominance to grass dominance. There is li...

پایان نامه :0 1374

in fact, this study focused on the following questions: 1. is there any difference between the effect of functional/notional approach and the structural approaches to language teaching on the proficiency test of efl learners? 2. can a rather innovative language test referred to as "functional test" ge devised so so to measure the proficiency test of efl learners, and thus be as much reliable an...

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 ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان - دانشکده مهندسی 1392

flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1389

after the soviet union dissolution, a chaotic period was begun in the russia. russia lost its glory and felt disgrace. the first group of elites came to power under yeltsin; they tried to re-define russia’s identity as a european country and build a foreign policy on this baseline. therefore russia tried to become closer with the west especially with the u.s. according to their view the sovie...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید