Accurate estimates of forest canopy are essential for the characterization of forest ecosystems. Remotelysensed techniques provide a unique way to obtain estimates over spatially extensive areas, but their application is limited by the spectral and temporal resolution available from these systems, which is often not suited to meet regional or local objectives. The use of unmanned aerial vehicle...

Tragacanth Gum is one of the most important medicinal and industrial productsof rangelands and is obtained from the incision of gum tragacanth-producing Astragalusincluding Astragalus keyserlingii. The conservation of Astragalus species in rangelandshas a special place in terms of economic profit and soil conservation. The increase in priceof gum tragacanth in recent years and more attention of...

Humans are rapidly altering natural systems, leading to changes in the distribution and abundance of species. However, so many changes are occurring simultaneously (e.g., climate change, habitat fragmentation) that it is difficult to determine the cause of population fluctuations from correlational studies. We used a manipulative field experiment to determine whether forest canopy cover directl...

the purpose of this study was to investigate vegetation dynamics and range conditions considering the climatic conditions and soil properties in doolat gharin in the south of isfahan province of an area equal to 25 square kilometer. for this purpose, after determining vegetation types and associated species, the type of rangeland utilization, grazing season, the type of livestock and other rele...

The desirable structure of longleaf pine forests, which generally includes a relatively open canopy of pines, very few woody stems in the mid-story, and a well-developed, herbaceous ground layer, provides critical habitat for flora and fauna and contributes to ecosystem function. Current efforts to restore longleaf pine to upland sites dominated by second-growth loblolly pine require informatio...

in order to evaluate capability of the landsat-etm and irs-p6-liss iv images for canopy cover mapping a case study was done on the forests of javanroud in kermanshah province. after evaluation of the geometric and radiometric quality of the data, the etm+ images, the etm+ images were geometrically corrected with gcps and the images were registered with rmse error 0.46 and 0.48 pixels, for x and...

We used a predictive model to map canopy cover of vegetation over seven feet in height (“tall woody vegetation”) at 30-meter resolution over nearly 29 million acres within and adjacent to the range of the greater sage-grouse in Oregon (Figure 1). Texture measures computed at various resolutions from colorinfrared aerial photography provided the main source of predictor data used to produce the ...

T h e effect of variable tree canopy cover, shadows, and topography on Thematic Mapper (TM) data was examined for blue oak (Quercus douglasii) woodland and wooded grassland on rugged terrain in central California. Thematic Mapper data were analyzed from September 1986 (trees in leaf, grass understory senescent) and December 1984 (trees leafless, grasses emerging. Tree cover measured in 84 60 m ...