نتایج جستجو برای: because of poor vegetation

تعداد نتایج: 21181358  

Journal: :آب و خاک 0
خدیجه سالاری نیک محسن نائل قاسم اسدیان علی اکبر صفری سنجانی

introduction: soil organic matter is influenced strongly by vegetation cover and management, therefore it is proposed as the main indicator of soil quality and health. the changes in soil organic matter status occur much more rapidly in the labile pools than in organic c. thus, labile pools can be used as early indicators of changes in total organic matter that will become more obvious in the l...

1997
Michael A. Patten

I conducted small-mammal trapping surveys on a desert scrub restoration site in Palm Springs, California, to document concomitant recovery of the rodent community. These surveys were conducted following quantitative vegetation sampling efforts that indicated that a predefined successful restoration criterion of 15% total shrub cover had been met throughout most of the area. But shrub cover, nat...

Journal: :international journal of health policy and management 0
stephen gill department of political science, york university, toronto, on, canada solomon r. benatar university of cape town, cape town, south africa

ilona kickbusch’s thought provoking editorial is criticized in this commentary, partly because she fails to refer to previous critical work on the global conditions and policies that sustain inequality, poverty, poor health and damage to the biosphere and, as a result, she misreads global power and elides consideration of the fundamental historical structures of political and material power tha...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید چمران اهواز - دانشکده ریاضی و کامپیوتر 1392

فرض می کنیم m وn، r- مدول های راست باشند، و می گوییم m وn- پروژکتیو است اگربرای هرr-مدول هم ریختی پوشایk f: n? وr- مدول هم ریخی k g: m?، r- مدول هم ریختی h:m?n موجود باشد به طوری که foh=g. ازنمادهای r-mod و r-mod ss استفاده می کنیم که به ترتیب به معنای کلاس تمامی r- مدول های راست و کلاس تمامی r- مدول های راست نیم ساده می باشند. هم چنین دامنه پروژکتیوی r- مدول های راست m را به صورت زیر تعریف می ...

2014
Matthew B. Russell Anthony W. D’Amato Bethany K. Schulz Christopher W. Woodall Grant M. Domke John B. Bradford

The contribution of understorey vegetation (UVEG) to forest ecosystem biomass and carbon (C) across diverse forest types has, to date, eluded quantification at regional and national scales. Efforts to quantify UVEG C have been limited to field-intensive studies or broad-scale modelling approaches lacking field measurements. Although large-scale inventories of UVEG C are not common, speciesand c...

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Soil erosion is of the most important environmental challenges and factors of forest damage, which is, occur because of the land use change, road construction and lack of vegetation cover. Forest soil is naturally penetrable but forest roads are not. This issue causes the flows runoff on road surface and washes soil particles. Thus, forest roads must be planned and constructed accurately. So, t...

Introduction Vegetation cover is an important indicator in the arid and semi-arid areas and plays an important role in balancing the ecosystems. Monitoring vegetation cover changes is of great importance because of vegetation effects on the environment. This monitoring provides detailed quantitative and qualitative information. It is therefore important to monitor dynamic changes in vegetatio...

2006
KEVIN TIMONEY

Factors that may account for subarctic vegetation patterns that are not reconcilable with synoptic climate were sought by reference to data on local climate, soils, parent materials, vegetation, and topography. Where the forest-tundra lies climatically northward, the vegetation transition zone is relatively narrow, and the soils are nutrient-rich, fine-textured loamy Cryosols derived from sedim...

2010
Toshpulot Rajabov

Since livestock production in Uzbekistan in arid and semi-arid zones is based on rangeland vegetation, contemporary studies have focused on improvement of low productive grazing lands and rehabilitation of degraded rangelands. Less interest has been given to the driving factors of land degradation and their interaction with other ecosystem components, e.g. response of vegetation to grazing indu...

2007
J. Peters B. De Baets E. C. Verhoest

Vegetation patterns arise from the interplay between intraspecific and interspecific biotic interactions and from different abiotic constraints and interacting driving forces and distributions. In this study, we constructed an ensemble learning model that, based on spatially distributed environmental variables, could model vegetation patterns at the local scale. The study site was an alluvial f...

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