نتایج جستجو برای: total canopy cover

تعداد نتایج: 911411  

2000
Scott N. Martens David D. Breshears Clifton W. Meyer

The understory light environment is a key determinant of vegetation pattern and ecosystem processes, and varies spatially perhaps more than any resource used by plants. Understory light varies along gradients of vegetation structure that range from grassland with no woody canopy cover to forest with nearly complete woody canopy cover. Spatial variability in understory light is largely determine...

Journal: :مرتع و آبخیزداری 0
حمید محمدی ، حمیدرضا کریم زاده جمال الدین خواجه الدین

study of soil and plant relationships is nessesery for ecological- based and appropriate management. the objective of this study is to determine the influence of edaphic properties on haloxylon persicum growth and also, indentifing growth limiting soil properties for saxaul. the study was performed through the stratified random sampling and 3 sites were selected as follow: planted strong saxaul...

The protection and improvement of natural resources especially for desert vegetation need a comprehensive recognition of natural resources and relationship on Soil characteristics. One of the most important species growing in sabzevar desert is Stipagrostis pennata and in the current research the relationship between the physicochemical properties of the soils and growth characteristics of the ...

Amir Mirzaei Mossivand, Ardavan Ghorbani Ehsan Zandi Esfahan Farshad Keivan Behjou

The aim of this study was to assess the regional effects of fire on the surface cover and forage production of mountainous rangelands of Delfan County, Lorestan province, Iran. The fire took placed in June 2007 with significant effects on the vegetation characteristics in the study area. Four fire affected sites were selected for sampling and a close area without fire was considered as control....

Journal: :بوم شناسی کشاورزی 0
سیده ثمانه هاشمی فائزه زعفریان اسفندیار فرهمندفر میلاد باقری شیروان

introduction amount and vertical distribution of leaf area are essential for estimating interception and utilization of solar radiation of crop canopies and, consequently dry matter accumulation (valentinuz & tollenaar, 2006). vertical distribution of leaf area is leaf areas per horizontal layers, based on height (boedhram et al., 2001). above-ground biomass is one of the central traits in func...

ژورنال: مرتع 2021
Bagheri, Setareh, Jafari, Mohammad, Malekian, Arash, Peyrvand, Vahid, Tamartash, Reza, Tatian, Mohammadreza,

Using satellite imagery is a reasonable option to overcome the field visits problems and limitations to evaluate the vegetation cover over the years. The present research has conducted to specify the percentage of vegetation cover of rangelands using Geographic Information System (GIS) and vegetation indices. The study area is located in Qazvin plain rangelands, Iran. In this study, the MODIS s...

2015
Bill Buffum Thomas J. McGreevy Amy E. Gottfried Mary E. Sullivan Thomas P. Husband Stephanie S. Romanach

The New England cottontail (Sylvilagus transitionalis) is a high conservation priority in the Northeastern United States and has been listed as a candidate species under the Endangered Species Act. Loss of early successional habitat is the most common explanation for the decline of the species, which is considered to require habitat with dense low vegetation and limited overstory tree canopy. F...

Maziar Haidari, Mehrnosh Shabanipour Nilofar Mostafa Soltani, Seyed Mostafa Moslemi Seyed Mahalleh

To detection of suitable sampling method to study tree canopy cover in the northern Zagros forest, Baneeh region forest, Kurdistan province, and west of Iran was selected. 40 square sample plots one hectare (100×100 m) were selected and perfect inventoried. In every sample plot the position of tree, kind of species and two diameter of crown (m) were recorded. To study of canopy cover different ...

Journal: :Remote Sensing 2017
Matthew J. Macander Gerald V. Frost Peter R. Nelson Christopher S. Swingley

Ecosystem maps are foundational tools that support multi-disciplinary study design and applications including wildlife habitat assessment, monitoring and Earth-system modeling. Here, we present continuous-field cover maps for tundra plant functional types (PFTs) across ~125,000 km2 of Alaska’s North Slope at 30-m resolution. To develop maps, we collected a field-based training dataset using a p...

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...

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