نتایج جستجو برای: canopy cover percentage

تعداد نتایج: 254028  

2013
John W. Coulston Dennis M. Jacobs Chris R. King

Quantifying tree canopy cover in a spatially explicit fashion is important for broad-scale monitoring of ecosystems and for management of natural resources. Researchers have developed empirical models of tree canopy cover to produce geospatial products. For subpixel models, percent tree canopy cover estimates (derived from fi ne-scale imagery) serve as the response variable. The explanatory var...

2006
LUIS SCHIESARI

1. The gradient in pond canopy cover strongly influences freshwater species distributions. This study tested the effects of canopy cover on the performance of two species of larval anurans, a canopy cover generalist (Rana sylvatica, the wood frog) and an open-canopy specialist (R. pipiens, the leopard frog), and tested which factors co-varying with canopy cover mediate these effects. 2. A field...

Journal: :Remote Sensing 2016
Paul Mannix Montesano Christopher S. R. Neigh Joseph O. Sexton Min Feng Saurabh Channan K. Jon Ranson John R. Townshend

Monitoring current forest characteristics in the taiga ́tundra ecotone (TTE) at multiple scales is critical for understanding its vulnerability to structural changes. A 30 m spatial resolution Landsat-based tree canopy cover map has been calibrated and validated in the TTE with reference tree cover data from airborne LiDAR and high resolution spaceborne images across the full range of boreal for...

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...

2005
M. Biradar Chandrashekhar Sameer Saran P. L. N. Raju P. S. Roy

Monitoring of forest cover is an essential tool for sustainable management of natural resources. Woody green cover can better maintained and managed by identification of forest gaps and their subsequent refilling. Forest canopy density mapping is one of the tools used to identify such canopy openings and most useful parameter to consider in the planning and implementation of afforestation and r...

Journal: :مرتع و آبخیزداری 0
محمد جعفری استاد دانشکدة منابع طبیعی دانشگاه تهران محمد طهمورث دانشجوی دکتری تخصصی آبخیزداری دانشکدة منابع طبیعی دانشگاه تهران محسن نقیلو کارشناس ارشد مرکز تحقیقات بین المللی بیابان دانشگاه تهران

the purpose of this research is investigation of relationship between vegetation cover and soil characteristics and determination of the most important soil factor that effects on quantity variations and kinds of vegetation cover in the study area. the study area is located in west of tehran province and south eastern of hashtgerd, next to najm-abad village. after field study, the index vegetat...

Density and diversity of birds in two different forest zones, namely, Shasta Kalateh Protected Forest and Alangdareh Recreational Forest, were estimated and compared. Birds and environmental variables were recorded within 25 m radius in 100 sampling points. The first axis of Canonical Component Analysis segregated two main groups of birds. The first group consisted of Black Woodpecker, Great Sp...

The purpose of this study was to investigate some environmental factors of Zagros forest dieback. In this regard, raster layers of elevation, slope, aspect, hillshade, toposhape and the land formation of Zagros forests in Ilam province were prepared. The distribution map of live and dieback forest cover were also prepared, using Landsat 8 panchromatic images. Then, the percentage of dieback for...

The Nearest Individual Sampling Method is one of the distance sampling methods for estimating density, canopy cover and height of forest stands. Some distance sampling methods have more than one density estimator that may be skewed to the spatial pattern. Unless the stands of the trees under study have a random spatial pattern. Therefore, the purpose of this study was evaluating the effect of s...

2013
ALAN D. YANAHAN Steven J. Taylor Sam W. Heads Andrew V. Suarez Anthony Yannarell

Formally assessing biodiversity can be a daunting if not impossible task. Subsequently, specific taxa are often chosen as indicators of patterns of diversity as a whole. Mapping the locations of indicator taxa can inform conservation planning by identifying land units for management strategies. For this approach to be successful, though, land units must be effective spatial representations of t...

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