نتایج جستجو برای: canopy cover perimeter

تعداد نتایج: 127446  

Amr Ali Shahmoradi Ehsan Zandi Esfahan Seyyed Morteza Abtahi,

Abstract. The purpose of this study was to investigate vegetation dynamics and range conditions considering the climatic conditions and soil properties in Haftooman, Khoor and Biabanak deserts, Iran. For this purpose, after determining vegetation types and the associated species, the type of rangeland utilization, grazing season, the livestock type, the other relevant information, vegetation da...

Journal: :journal of rangeland science 2012
seyyed ali hosseini jamshid khatir namany morteza akbarzadeh

studies on vegetation changes of rangelands under grazed and non-grazedconditions are of great importance in the range management planning programs. to determinethe change process of vegetation, this study was performed in inche shorezar site of golestanprovince for nine years (1997-2005). the vegetation parameters were measured every year inseveral fixed plots inside and adjacent of exclosures...

Importance of probability distribution functions in natural resource studies is increasing due to their effective roles in better understanding of vegetation structure and providing conceptual models of quantitative indices of plant species. The present study was performed to model the distribution of height and canopy area of Cionura erecta L. shrub, using probability distribution functions in...

The aim of the study was to determine the most important environmental factors (topography, climate, and soil) affecting changes in production and canopy cover of plant variations and to prepare prediction maps, based on the most important factor, in semi-steppe rangelands of Hir-Baghrou, Ardabil province, Iran. First, by detecting the vegetation types and different classes of environmental fac...

2007
Chad S. Boyd Jon D. Bates Rick F. Miller

Sagebrush cover is often estimated with the use of the line intercept method. However, a lack of standardized protocols may lead to variable estimates of sagebrush canopy cover. Our objectives were to determine the influence of gap size on 1) sagebrush canopy cover estimates, 2) time needed to read a transect, and 3) among-observer variability in sagebrush canopy cover estimates. We utilized 5-...

Journal: :journal of rangeland science 2014
seyyed morteza abtahi amr ali shahmoradi ehsan zandi esfahan

abstract. the purpose of this study was to investigate vegetation dynamics and range conditions considering the climatic conditions and soil properties in haftooman, khoor and biabanak deserts, iran. for this purpose, after determining vegetation types and the associated species, the type of rangeland utilization, grazing season, the livestock type, the other relevant information, vegetation da...

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...

2007
Chris B. Zou Greg A. Barron-Gafford David D. Breshears

[1] The emerging interdisciplinary approaches of ecohydrology and hydropedology are sensitive to variation in soil-surface energy inputs, which are primarily modified by topography and woody plant canopies. Yet a synthesis of the interactive effects of these two modification types is lacking. We systematically estimated near-ground surface solar radiation inputs as modified by key attributes of...

2017
Dongliang Wang Xiaoping Xin Quanqin Shao Matthew Brolly Zhiliang Zhu Jin Chen

Accurate canopy structure datasets, including canopy height and fractional cover, are required to monitor aboveground biomass as well as to provide validation data for satellite remote sensing products. In this study, the ability of an unmanned aerial vehicle (UAV) discrete light detection and ranging (lidar) was investigated for modeling both the canopy height and fractional cover in Hulunber ...

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