نتایج جستجو برای: vegetation cover density and type
تعداد نتایج: 17062927 فیلتر نتایج به سال:
in this study, we applied classification methods and geographic information system(gis) techniques to identify vegetation structures in andevar rangelands. homogenous work unit maps were produced by overlaying the layers of slope, aspect and digital elevation. totally 95 homogenous units were determined in which the field studies were carried out. vegetation sampling was done in 69 transects an...
To investigate land use changes, Qale Shahrokh basin (15098.1 ha area) was selected. Satellite images of Landsat sensors (MSS, TM and ETM+) were used. After improvement and different enhancement analysis of images such as FCC, PCA, the study area was checked using GPS and topographic maps (1:50000) and other information. Land use units were determined using classified random sampling method. Ma...
A number of halophytic species as Salicornia europea, Halocnemum strobilaceum, Aeluropus lagopoides, and Aeluropus littoralis were found to occupy a significant portion of the total vegetation of the surrounding area at the Zayande-Roud inlet to Gavkhoony wetland. However, their ecological demands and bioenvironmental factors by which vegetation community composition has been affected is not un...
Presence of invasive species on rangelands is a degradation sign. The aim of this study was to evaluate the effects of invasive species Leucanthemum vulgare Lam. on the structural and functional characteristics of Fandoghlou rangelands in the Namin county of Ardabil province. The model used for sampling was the stratified random systematic. Two main sites with the presence and absence of L. vul...
The spatial distribution of soil organisms is influenced by the plant cover, thus resulting in a horizontal mosaic of areas subjected to gradients of nutrient availability and microclimatic conditions.This study was conducted to investigate the spatial variability of soil macrofauna in relation to vegetation density in the riparian forest landscape of Karkhe. The vegetation density was determin...
Scrub typhus is transmitted by the larval stage of trombiculid mites. Environmental factors, including land cover and land use, are known to influence breeding and survival of trombiculid mites and, thus, also the spatial heterogeneity of scrub typhus risk. Here, a spatially autoregressive modelling framework was applied to scrub typhus incidence data from Taiwan, covering the period 2003 to 20...
Validating model simulations of vegetation-climate feedback needs information not only on changes in past vegetation types as reconstructed by palynologists, but also on other proxies such as vegetation cover. We present here a quantitative regional vegetation cover reconstruction for North China during the Holocene. The reconstruction was based on 15 high-quality lake sediment profiles selecte...
Using accurate and low-cost methods to monitor quantitative changes in vegetation cover play an important role in the efficient and sustainable management when the area is too large. In this study, the changes of vegetation cover were investigated using satellite data of TM (Landsat_5) and oli (Landsat_8) sensors for a 30-year period (1988-2018) in Chaharbagh rangeland of Golestan province. T...
To investigate land use changes, Qale Shahrokh basin (15098.1 ha area) was selected. Satellite images of Landsat sensors (MSS, TM and ETM+) were used. After improvement and different enhancement analysis of images such as FCC, PCA, the study area was checked using GPS and topographic maps (1:50000) and other information. Land use units were determined using classified random sampling method. Ma...
Extended abstract 1-Introduction Desertification means land degradation in the arid, semi-arid and dry sub-humid regions because of natural or anthropogenic factors. Desertification is accounted as the third most important global challenge after the crisis of water shortage and drought in the 21st century. Desertification is a problem for many countries, especially the developing countries. I...
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