نتایج جستجو برای: canopy cover perimeter

تعداد نتایج: 127446  

Journal: :Irrigation Science 2021

Having an accurate yet simple method to estimate crop evapotranspiration (ETC) is a vital component of reliable irrigation scheduling. In this study, two versions the two-source energy balance (TSEB) model: TSEB model with Priestley–Taylor equation (TSEB-PT) and Penman–Monteith (TSEB-PM), were used ETC dry edible beans in western Nebraska. Compared previous studies, study unique that Visual Bas...

ژورنال: علوم آب و خاک 1997
بصیری, مهدی , خواجه الدین, سیدحمال الدین , وهابی, محمد رضا ,

Short-term changes (5 years) in canopy cover, species composition and forage production were studied under protection from grazing and grazed condition in 19 range sites in Fereydan region, Isfahan province. In this study, density, canopy cover and forage production data were obtained from quadrates inside and outside exclosures in the spring of 1983. These parameters were studied again in 1988...

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...

The aim of this study was to investigate the role of species of Trifolium genus on the composition, diversity, forage value and quantitative vegetation parameters and interaction between Trifolium species and invasive species Leucanthemum vulgare Lam. in Fandoghlou rangelands in Ardabil province. In determining the sampling locations, six sites by systematic random method and due to the distrib...

2016
Glen L. Ritchie Esmaiel Malek Robert R. Gillies

Spectral reflectance of plant canopies provides an accurate indication of ground cover fraction, which is highly correlated with radiation capture. If nutrients and water do not limit growth, radiation capture is highly correlated with daily growth rate and ultimate yield. However, if nutrients and water limit growth, none of the common spectral indices are able to separate a more developed, st...

2008
Tim Whiteside Waqar Ahmad

Very high spatial resolution satellite imagery provides data that enables spatially detailed analysis of landscapes. The identification and extraction of information about tree crowns is one such use. Tree crown or canopy cover is one parameter of vegetation structural classification. The estimation of canopy cover has a wide range if uses related to management and policies. Tree crown extracti...

2011
Yuri Knyazikhin Mitchell A. Schull Liang Xu Ranga B. Myneni Arindam Samanta

The concept of canopy spectral invariants expresses the observation that simple algebraic combinations of leaf and canopy spectral reflectance become wavelength independent and determine two canopy structure specific variables – the recollision and escape probabilities. These variables specify an accurate relationship between the spectral response of a vegetation canopy to incident solar radiat...

Journal: :اکو هیدرولوژی 0
سعید یوسفی کارشناس ارشد بیابان زدایی، دانشکدة منابع طبیعی، دانشگاه صنعتی اصفهان، اصفهان سید حمید متین خواه استادیار، دانشکدة منابع طبیعی، دانشگاه صنعتی اصفهان، اصفهان فرزاد روحانی مربی، دانشکدة منابع طبیعی، دانشگاه صنعتی اصفهان، اصفهان محسن نائل استادیار، دانشکدة کشاورزی، دانشگاه همدان

stemflow is a part of precipitation which enters in to the soil through stem and branches. in this paper, we studied the stem flow features of anabasis aphylla as a bush and pteropyrum aucheri as a shrub in northwest of isfahan. stemflow production mechanism as well as the effects of canopy cover on this system was investigated during precipitation seasons in 2013 and 2014. a rain simulator was...

2008
T. Emiko Condeso Ross K. Meentemeyer

As the emergence of invasive pathogens and their impacts on ecological communities increases, so has the interest in understanding how landscape pattern (in other words the configuration and composition of suitable habitat) affects their establishment and spread. Plant pathogen invasions are inherently spatial, but few studies have demonstrated the role of landscape pattern on disease dynamics....

اشرف زاده, محرم, عرفانزاده, رضا,

This study aimed to investigate the effect of canopy cover of individual woody patches on soil seed bank characteristics viz. density, richness and the similarity between soil seed bank and above ground vegetation. The study was conducted in Mazayjan, Zarindasht, south of Fars province in 2013. Therefore, 40 4m2 plots beneath and outside of Ziziphus spina-christi (dominant woody species) were e...

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