نتایج جستجو برای: vegetation cover density and type
تعداد نتایج: 17062927 فیلتر نتایج به سال:
The aim of this study was to investigate relationships between soil properties and plant species to determine the most effective factors separating vegetation communities in Rineh rangeland. Three stratifying variables were selected including slop, aspect and elevation. The study area was partitioned by combining these classes to generate homogenous units. 1m2 quadrates were located at sampling...
Factors controlling savanna woody vegetation structure vary at multiple spatial and temporal scales, and as a consequence, unraveling their combined effects has proven to be a classic challenge in savanna ecology. We used airborne LiDAR (light detection and ranging) to map three-dimensional woody vegetation structure throughout four savanna watersheds, each contrasting in geologic substrate and...
abstract. rangeland vegetation dynamics encompass all processes of changes in vegetation composition and structure over time. investigating the rangeland ecosystem dynamics makes it possible to determine the effects of climatic and management conditions on qualitative and quantitative changes of the vegetation in a specific period of time. accordingly, data collection and measurements for evalu...
land surface temperature (lst) is an important factor in global change studies. the information about lst has an important role in the range of issues and themes in earth sciences such as global environment change, human-environment interaction and more specifically to urban climatology. this research has been undertaken to analyze the potential of multispectral satellite data for retrieving th...
The study of vegetation dynamics under grazed and non-grazed rangelands is one of the most important prerequisites for range improvement. In this research, vegetation composition and the vegetation functional groups were compared in an exclosure site (livestock excluded for six years) and grazed area in semi-steppe rangelands in Tehran province. Systematic random sampling technique through the...
in the absence of herbicides, cover crops play an important role for weed management in organic than in conventional farming. therefore, in order to evaluate the effects of cover crop management and plant density of buckwheat (fagopyrum esculentum) as cover crop on weed suppression, a field experiment was conducted at the research farm of university of zanjan, during the growing season of 2011....
Investigation of the relationship between plant species and environmental factors plays an important role in plant ecology. The present study aimed to develop the best predicting model for distribution of Prangos uloptera DC. using logistic regression (LR) and Maximum Entropy Methods (MaxEnt) in its habitat in the southern rangeland of Ardabil province, Iran. Vegetation data (presence and absen...
This research was aimed to simulate and prioritize the effective factors on water erosion using USLE-M in the system dynamic model. In this integrated model, by using the system dynamic simulation software (Vensim), all variables and factors involved in erosion and soil loss were considered according to the USLE-M model. After model implementation, the estimated values and observations were com...
In order to evaluate the effects of forest road on vegetation and some soil properties was selected a road with the length of 400 m. Type and number of regeneration species of trees and shrubs in plot area of 100 m2 and type and cover percentage of herbaceous species using minimal area method were recorded in plot area of 64 m2 and herbaceous species was classified into two groups using Two-W...
Forest fire brings forest destruction as an important part of human environments, air pollution, and the loss of wealth and facilities, and endangers the lives of human beings in the vicinity of the forest. It is one of the examples of natural crises and is considered to be a crisis management. Identifying the effective factors in the occurrence of fire and hazard zoning is one of the basic too...
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