نتایج جستجو برای: high vegetation

تعداد نتایج: 2095458  

ژورنال: :مرتع و آبخیزداری 2012
فاضل امیری حسن یگانه

assessment process of vegetation cover by remote-sensing images should be based on understanding of the vegetation indices. vegetation indices are widely used for assessing and monitoring ecological variables such as vegetation cover, above-ground biomass and leaf area index. the aim of the present research was to study of the aster data capabilities to estimate the vegetation cover percentage ...

2004
S. Brand

Vegetation change detection has become increasingly important in understanding vegetation dynamics and its role in terrestrial and atmospheric systems. In the case of Scotland, there is a need to routinely monitor habitats which include native pine woodland, montane habitats, upland heathland and blanket bog (EC Habitats Directive). In northern temperate regions restricted and distinct growing ...

Journal: :Journal of plant physiology 2004
Anatoly A Gitelson

The Normalized Difference Vegetation Index (NDVI) is widely used for monitoring, analyzing, and mapping temporal and spatial distributions of physiological and biophysical characteristics of vegetation. It is well documented that the NDVI approaches saturation asymptotically under conditions of moderate-to-high aboveground biomass. While reflectance in the red region (rho(red)) exhibits a nearl...

Journal: :محیط شناسی 0
اسلام زرینه کارشناسی ارشد مرتع، دانشگاه شهرکرد مهدی نادری خوراسگانی استادیار گروه خاک شناسی، دانشکدة کشاورزی دانشگاه شهرکرد اسماعیل اسدی بروجنی استادیار گروه مرتع و آبخیز، دانشکدة منابع طبیعی و علوم زمین دانشگاه شهرکرد

rangelands encompass 55% of iran's territory. monitoring of such resources is inevitable due to dynamic behavior and extremely high extension. scanning of land resources data by satellites facilitates monitoring the rangelands. this research was carried out to study the relationships of vegetation indices derived from irs liss-iii data with vegetation cover of tange sayyad region in the ch...

The degradation rate of Mediterranean steppes, especially in North Africa is 1% per year, and this considered a high  rate of degradation. This study conducted in 2014 in the south slope of the Al-Jabal Al-Akhdar, northeast Libya to quantify the vegetation recovery rate and assess selected Vegetation Indices (VIs) for mapping rangelands degradation status using remote sensing technology. Throug...

2000
Christopher D. Clegg Karl Ritz Bryan S. Griffiths

Total DNA was directly extracted from microbial populations in grassland soils taken from three geographically distinct upland sites at Garrigill, Aber and Sourhope, UK. Within each site, grasslands were categorised using the National Vegetation Classification into distinct vegetation sequences, namely unimproved, semi-improved and improved. Microbial community DNA was extracted from the differ...

Journal: :Global change biology 2015
John Harte Scott R Saleska Charlotte Levy

Ecosystem responses to climate change can exert positive or negative feedbacks on climate, mediated in part by slow-moving factors such as shifts in vegetation community composition. Long-term experimental manipulations can be used to examine such ecosystem responses, but they also present another opportunity: inferring the extent to which contemporary climate change is responsible for slow cha...

2014
Chun-Huo Chiu Anne Chao

In this Appendix, we summarize some basic properties of the three classes of functional diversity measures: (1) functional Hill number ) (Q D q which quantifies the effective number of equally abundant and equally distinct species in an assemblage with a constant species pairwise distance Q, where Q denotes Rao’s quadratic entropy; (2) mean functional diversity MD(Q) = Q Q D q × )] ( [ which qu...

Journal: :international journal of environmental research 2013
m.h. mokhtari b. ahmad h. hoveidi i. busu

metric (mapping evapotranspiration at high resolution with internalized calibration) is known as an appropriate surface energy balance model for the estimation of the spatial distribution of evapotranspiration (et) in semi-arid regions. based on lysimeter measurements, metric has shown et estimates of 10% on a sub-field scale on a daily basis. there is a need to identify how the model is sensit...

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