نتایج جستجو برای: m apart within eachsampling area production and cover were estimated within 10 located 2
تعداد نتایج: 17565144 فیلتر نتایج به سال:
The vegetation cover and rangeland production are the most important factors to determine the proper planning system for effective utilization and management of rangelands. In this research, the effect of climatic factors (temperature and rainfall) were studied on vegetation cover and forage production of four species (Festuca ovina, Bromus tomentellus, Dactylis glomerata and Agropyron trichoph...
Siberian silkmoth (Dendrolimus sibiricus Tschetv.) is a dangerous pest that has affected nearly 2.5 × 106 ha of “dark taiga” stands (composed of Abies sibirica, Pinus sibirica and Picea obovata) within the latitude range of 52◦–59◦ N. Here we describe a current silkmoth outbreak that is occurring about half degree northward of its formerly documented outbreak range. This outbreak has covered an...
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...
annually, 200 ha of agh ghala rangelands in golestan, iran are under alkaligrass puccinella distans's cultivation but the failure in the identification of appropriate sites for seed sowing may result in high costs of cultivation. the current study aims to reduce such costs through the examination of apt sites to grow p. distans in northern rangelands of agh ghala golestan, iran. because of the ...
annually, 200 ha of agh ghala rangelands in golestan, iran are under alkaligrass puccinella distans''s cultivation but the failure in the identification of appropriate sites for seed sowing may result in high costs of cultivation. the current study aims to reduce such costs through the examination of apt sites to grow p. distans in northern rangelands of agh ghala golestan, iran. because of the...
Predicting species’ distribution is a prerequsit for assessing threats, determining conservation status, and planning conservation programs. Asian houbara Chlamydotis macqueenii is one of the most valuable game species threatened by extinction. We estimated the distribution of potential suitable habitats of wintering populations of Asian houbara bustard in central Iranian plateau using maximum ...
Snow is a huge water resource in most parts of the world. Snow water equivalent supplies 1/3 of the water requirement for farming and irrigation throughout the world. Water content estimation of a snow-cover or estimation of snowmelt runoff is necessary for Hydrologists. Several snowmelt-forecasting models have been suggested, most of which require continuous monitoring of snow-cover. Today mo...
Earthquake has always endangered cities. This article mainly focuses on the question “whether seismic damages could be diminished through the presentation a preventive operational pattern dealing with physical and nonphysical features of civil defense”. Tehran, the most populous metropolis among Iranian cities is to the south of Alborz mountain range, located on potentially dangerous fault- lin...
Forest fragmentation results in a loss of forest interior and an increase in edge habitat. We studied how understorey bird community composition and habitat variables changed along an edge-to-interior gradient in a 1248-ha lowland rainforest patch in peninsular Malaysia. Birds and environmental variables such as vegetation structure and litter depth were detected within a 25-m radius of each of...
This study extracted production forests and estimated the annual available amounts of forest biomass resources under profitable forest management. Production forests were extracted as sub-compartments where expected revenues surpassed all costs, from planting to final harvesting, for a 60-year rotation. These revenues and costs were estimated for two types of timber harvesting systems (a conven...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید