نتایج جستجو برای: arid flora and vegetation

تعداد نتایج: 16844048  

2016
Ignacio Bordeu Marcel G. Clerc Piere Couteron René Lefever Mustapha Tlidi

Desertification due to climate change and increasing drought periods is a worldwide problem for both ecology and economy. Our ability to understand how vegetation manages to survive and propagate through arid and semiarid ecosystems may be useful in the development of future strategies to prevent desertification, preserve flora-and fauna within-or even make use of scarce resources soils. In thi...

2012
Stephen Harris Stephen Summers

East Kangaroo Island is a low, mostly calcarenite-covered granitic island in the Furneaux Group which was observed in 1828 to have been fertile and well-wooded by Allocasuarina verticillata. Over 160 years of grazing and a succession of drought years have contributed to the decline of the native vegetation in biomass, ground cover and native species diversity. In the summer 0[1999/2000, bare gr...

Ali Mahamane Ambouta J.M. Karimou Boubacar M. Moussa Mahamane Saadou SOUMANA Idrissa, Youssoufa Issiaka

Description of vegetation patterns associated with environmental factors such as grazing, climate, landforms, substrate variables etc. are helpful for land management planning. This study used new synecological tools to investigate plants composition and to provide ecological descriptions of plants communities of communal pastures in Sahelian Ecological Zone of Niger. Vegetation and several env...

ژورنال: مرتع 2023
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Background and objectives A large area of Iran rangelands is located in arid and semi-arid areas which a significant percentage of them have been degraded and are not in good condition. In these areas, vegetation restoration is not easy due to the water scarcity. Water harvesting operations are among the necessary management measures to restore and develop the rangelands of these areas. Water ...

Journal: :Brazilian journal of biology = Revista brasleira de biologia 2014
R J V Alves N G Silva J A Oliveira D Medeiros

Currently campo rupestre (CR) is a name accepted and used internationally by botanists, zoologists, and other naturalists, usually applied to a very specific ecosystem, despite the lack of a consensual published circumscription. We present a tentative geographic circumscription of the term, combining data on climate, geology, geomorphology, soil, flora, fauna and vegetation. The circumscription...

Journal: :desert 2012
h. azarnivand m.a. zare chahouki h. joneidi

one of the characteristics in iranian model of desertification potential assessment (imdpa) is vegetation. sincevegetation is very important factor in the degradation of land, so some indices were determined for this item in order toevaluate desertification potential of arid, semi arid and arid sub humid areas of iran. the indices included vegetationcondition, exploit and revegetation. to calib...

Journal: :journal of rangeland science 2012
sedigheh zare kia hossein arzani mohammad jafari seyyed akbar javadi ali ashraf jafari

this study aims to assess the effect of grazing intensity on vegetation structure, soil nutrient concentrations and soil physical properties. the study was carried out in steppe rangelands of saveh, markazi province, iran. four sites with four grazing intensities including very high, high, moderate and non-grazed with the same ecological conditions were selected. to study various vegetation and...

Journal: :desert 0
h. azarnivand associate professor, faculty of natural resources, university of tehran, karaj, iran m.a. zare chahouki associate professor, faculty of natural resources, university of tehran, karaj, iran h. joneidi assistant professort, university of kurdestan, sanandaj, iran

one of the characteristics in iranian model of desertification potential assessment (imdpa) is vegetation. sincevegetation is very important factor in the degradation of land, so some indices were determined for this item in order toevaluate desertification potential of arid, semi arid and arid sub humid areas of iran. the indices included vegetationcondition, exploit and revegetation. to calib...

Journal: :Remote Sensing 2015
Yunbo Bi Hongjie Xie

In arid regions, C3 vegetation is assumed to be more sensitive to precipitation and CO2 fertilization than C4 vegetation. In this study, normalized difference vegetation index (NDVI) is used to examine vegetation growth in the arid Lower Heihe River Basin, northwestern China, for the past three decades. The results indicate that maximum NDVI (MNDVI) of the area increases over the years and is s...

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...

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