نتایج جستجو برای: arid rangelands

تعداد نتایج: 20677  

2015
Nathan A. Nelson Jennifer Pierce

Rangelands are characterized by more arid climates than forested regions; therefore, establishing fire histories using traditional methods (e.g. fire-scars from trees or charcoal in lake sediments) is problematic. This study uses radiocarbon dating of charcoal preserved in alluvial fans and stream deposits to reconstruct a record of fire and geomorphic response in rangelands of southwestern Ida...

Journal: :journal of rangeland science 2014
amir saadatfar hossein barani abdol reza bahremand ali reza massah bavani adel sepehry

rangelands are one of the most vulnerable parts concerning the climatechanges‟ impacts. these impacts are even stronger in the arid and semi-arid areas whererangeland ecosystems are in critical conditions. therefore, it is crucial to figure out theactual dynamics of climate variations on the rangelands. the aim of this research was todetermine climate changes in khabr rangeland, kerman, iran. s...

Journal: :Frontiers in Ecology and Evolution 2021

Degradation characterized by depleted vegetation cover is a serious environmental problem in African rangelands. It poses threat to millions of pastoralists and agropastoralists who depend on livestock as source livelihood. Consequently, there has been growing global interest consolidate efforts restore degraded ecosystems. For example, the UN decade Ecosystem Restoration initiative aims at uni...

ایروانی, مجید , بشری, حسین , خواجه الدین, سید جمال الدین , طهماسبی, پژمان , نقی پور برج, علی اصغر ,

Fire products (smoke, ash and heat) have widely been recognized as a germination cue for some species from both fire prone and fire-free ecosystems. It is an important factor for the understanding of vegetation dynamics and could have potential use for ecological management and rehabilitation of disturbed area. This study attempts to understand the effect of the main fire products (smoke, ash a...

Journal: :journal of rangeland science 2013
tahereh sadeghi shahrakht mohammad jankju mansour mesdaghi

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...

Enclosure and Acacia shade availability to plants are basic variable in arid and semi-arid rangelands. the aim of this study was investigation the impact of patch enclosure and Acacia shade using four treatments which are Inside Enclosure Under Acacia shade (IEUA), Inside Enclosure Without Acacia shade (IEWA), Outside Enclosure Under Acacia shade (OEUA) and Outside Enclosure W...

2011
A. J. Fynn P. Alvarez J. R. Brown C. Kustin M. R. George E. A. Laca C. P. Wong

Rangelands are uncultivated lands that include grasslands, savannahs, steppes, shrub lands, deserts and tundra. The native vegetation on rangelands is predominantly grasses, forbs and shrubs (Kothmann, 1974). Rangelands cover 31 percent of the land surface area of the United States (Havstad et al., 2009), and up to half of the land surface area worldwide (Lund, 2007). Most land areas that are n...

Journal: Desert 2009
A. Tavili J. Farzadmehr M. Rostampour m.a Zare Chahouki

Abstract This paper presents a quantitative account of vegetation–environmental factor relationships in arid rangelands. Vegetation cover was recorded using Braun-Blanquet combined abundance-cover scale in each quadrat. Within each quadrat, one profile was dug and soil samples being taken at 0-20cm and 20-100cm depths. Under study physical-chemical characteristics included texture, lime, orga...

Journal: Desert 2020
A. Abolhasani Gh.R. Zehtabian, H. Khosravi, M. Jafary Sh. Javadi

Compared to surface water, groundwater resources are the primary source of water supply in arid and semi-arid regions of Iran, hence the importance of the management of these resources .  In this regard, we assessed the effects of landuse changes on the qualitative and quantitative status of groundwater resources in Eshtehard region, Iran. Through processing and analyzing the satellite images, ...

2010
E. Estell

Rangelands throughout the world contain varying but often substantial proportions of shrubs. Shrubs are generally heavily chemically defended, and herbivores must either contend with their plant secondary metabolites (PSM) or avoid a significant component of the available forage. Browsing ruminants are exposed to thousands of chemicals in infinite combinations and concentrations that are consta...

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