نتایج جستجو برای: total vegetation cover decreased by 362

تعداد نتایج: 7530927  

For an optimum use of natural resources in the sustainable development trend, there is a need to identify ecological resources in the shortest period of time and minimum possible cost. In this article, we aimed Management ecosystem by Assessment of plant covers changes at Taleghan Township in a twenty year period. Percentage of landscape and number of patch were among the metrics that were calc...

The study of plant communities is the best way to learn about vegetation structure and distribution as well as various interactions among the plants in an ecosystem. Elevation factor plays a vital role in plant distribution that ultimately leads to specific phytogeographic regions. This study evaluated the changes in species composition, density, frequency, canopy cover and palatability of spec...

ژورنال: آبخیزداری ایران 2019
, , soufi, majid, yasrebi, banafshe,

Gully erosion is one of the important forms of soil degradation especially in semi-arid areas. Gullies are occupying 13 percent of Ilam Province area. This research focused on studying the, topographic threshold of gullies, dominant process of gully initiation and development as well, in agricultural and rangeland land uses. Ilam province with 2 million hac area is located in western Iran. Ilam...

2004
Vivek Arora

[1] Using a simple dynamic vegetation model coupled to an intermediate complexity climate model Kleidon [2004] suggests that an optimum stomatal conductance exists at which vegetation productivity is maximized. It is suggested that this maximum is the result of two competing processes: 1) the increased supply of CO2 with increased stomatal conductance and 2) increased cloud cover, associated wi...

Journal: :journal of rangeland science 2010
a. mirjalili

in this investigation, the effects of enclosure, restal delayed grazing andcontinued grazing treatments on the production rate and vegetation cover were studied.study area was sadrabad pasture. after selecting three bands (1+1+1=3 hectare area) asthree treatments in the restricted and non restricted area, they were transected to threetransects. then plots (1×2m2 ) were selected to measure the p...

2006
P. Flombaum O. E. Sala

We present the calibration of a fast and non-destructive method to estimate aboveground plant biomass measuring vegetation cover. We double-sampled vegetation cover and aboveground biomass in the Patagonian steppe using 150 plots for shrubs and 50 plots for grasses. We performed simple linear regressions between vegetation cover and biomass for the dominant species and life forms (shrubs: Mulin...

2015
Christos Vasilikiotis Athanasios Gertsis Konstantinos Zoukidis Ali Nasrallah

Cover crops are essential in agricultural management and especially in organic farming for protecting the soil from erosion, competing with weeds, preventing evaporative losses and improving soil quality and fertility. The choice of cover crop species is crucial in achieving the highest level of weed suppression and soil fertility enhancement. Cover crop systems with rye or mixtures of legumes ...

Journal: :آب و خاک 0
سلیمان پور سلیمان پور صوفی صوفی احمدی احمدی

abstract gully erosion is a kind of water erosion that has high priority in fars province due to sediment production and enormous damages to land, roads and infrastructures. in this study, 15 gullies were selected and their morphometric characteristics, such as catchment area, soil, cover vegetation and climate were measured. in order to determine influential factors on the sediment production ...

2015
Jien Zhang Tianming Wang Jianping Ge Jian Liu

In the aftermath of the severe droughts and floods at the end of the 20th century, the Chinese government launched several ecological restoration projects, including the Natural Forest Protection Program in 1998 and the Grain-for-Green Program in 1999, to promote afforestation and reforestation to reduce surface runoff and consequent soil erosion nationwide. However, it is still unclear how veg...

2008
O. Durán

In this work we present measurements of vegetation cover over parabolic dunes with different degree of activation along the north-eastern Brazilian coast. We are able to extend the local values of the vegetation cover density to the whole dune by correlating measurements with the gray-scale levels of a high resolution satellite image of the dune field. The empirical vegetation distribution is f...

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