the study of the exclosure effects on the vegetation changes undergrazing and non-grazing conditions in the rangeland areas has particularimportance in the rangeland improvement and revivification projects. theresearch was accomplished in semi-steppe khoybilehvar area, from 1999 to2005. vegetation cover was annually measured within fixed plots during transact.the results showed that during nine...

a r t i c l e i n f o Keywords: Crop model CSM DSSAT Genetic algorithm Hyperspectral LAI Model inversion Nitrogen Optimization PEST PROSAIL Simulation Wheat Yield Remote sensing technology can rapidly provide spatial information on crop growth status, which ideally could be used to invert radiative transfer models or ecophysiological models for estimating a variety of crop biophysical propertie...

A first-return laser rangefinder deployed from a low-flying helicopter provided inexpensive, repeatable, and high-resolution measurements of the shape of the outer forest canopy in stands of four successional stages on the Maryland coastal plain. The traces of canopy height in these stands revealed structural characteristics such as cover, maximum and mean heights which were consistent with cor...

Estimating plant traits in herbaceous plant assemblages from spectral reflectance data requires aggregation of small scale trait variations to a canopy mean value that is ecologically meaningful and corresponds to the trait content that affects the canopy spectral signal. We investigated estimation capacities of plant traits in a herbaceous setting and how different trait-aggregation methods in...

This thesis presents a 3D virtual plant modelling study to tillering (lateral branching) in spring wheat (Triticum aestivum L.). Tillering in wheat is influenced by light properties. Light intensity determines the amount of assimilates available for growth. Availability of assimilates is assumed to regulate the degree of tillering: a reduction in light intensity, or more specifically in the int...

Forested ecosystems in the southeastern United States are currently undergoing an invasion by the hemlock woolly adelgid (HWA). Previous studies in this area have shown changes to forest structure, decreases in canopy cover, increases in organic matter, and changes to nutrient cycling on the forest floor and soil. Here, we were interested in how the effects of canopy loss and nutrient leakage f...

[1] This paper addresses the effects of canopy physical processes on snow mass and energy balances in boreal ecosystems. We incorporate new parameterizations of radiation transfer through the vegetation canopy, interception of snow by the vegetation canopy, and under-canopy sensible heat transfer processes into the Versatile Integrator of Surface and Atmosphere (VISA) and test the model results...

plants cover composition, condition, trend, production, and grazing capacity of the rangeland change annually. in this research, the role of temporal rainfall distribution on rangeland production was assessed. this research had down in the rangelands of ilam (with semiarid to semi humid climate) and qom and markazi (with arid to semiarid climate) provinces. by attention on plant cover maps in e...

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 ...