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...

Maintaining standing vegetative soil cover is an important method of wind erosion control. However^ an improved physical understanding of the mechanisms by which standing vegetation control wind erosion is needed so the erosion control level of vegetation not previously tested in a wind tunnel can be calculated. In this report, a theoretical approach that accounts for both the surface friction ...

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...

Three-dimensional (3D) reconstruction of a tree canopy is an important step in order to measure canopy geometry, such as height, width, volume, and leaf cover area. In this research, binocular stereo vision was used to recover the 3D information of the canopy. Multiple images were taken from different views around the target. The Structure-from-motion (SfM) method was employed to recover the ca...

abstract the objective of current research is to investigate distribution patterns of vegetation types and its relation with environmental factors in southern margin of haj aligholi kavir of damghan. three vegetation types including halecnemum strobilaceum, sedlitzia rosmarinus and artemisia sieberi were studied in marginal arid regions and uplands of the study area. firstly, geographic locatio...

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 ...

BACKGROUND AND AIMS Maximizing photosynthesis at the canopy level is important for enhancing crop yield, and this requires insights into the limiting factors of photosynthesis. Using greenhouse cucumber (Cucumis sativus) as an example, this study provides a novel approach to quantify different components of photosynthetic limitations at the leaf level and to upscale these limitations to differe...

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 ...