Estimation of Gap Fraction and Foliage Clumping in Forest Canopies
نویسندگان
چکیده
منابع مشابه
A rotated ellipsoidal angle density function improves estimation of foliage inclination distributions in forest canopies
The ‘ellipsoidal distribution’, in which angles are assumed to be distributed parallel to the surface of an oblate or prolate ellipsoid, has been widely used to describe the leaf angle distribution (LAD) of plant canopies. This ellipsoidal function is constrained to show a probability density of zero at an inclination angle of zero; however, actual LADs commonly show a peak probability density ...
متن کاملImproved algorithm for estimating canopy indices from gap fraction data in forest canopies
An algorithm has been proposed to estimate the leaf area index (LAI) and canopy closure of forest canopies from the distribution of gap fraction measured by an LAI-2000 plant canopy analyser by inverting a forest gap fraction theoretical formula. The algorithm is based on the idea that the canopy closure is estimated from the reading of canopy analyser in the near-zenith ring. However, the meas...
متن کاملLeaf area index measurements
Leaf area index (LAI) is a key structural characteristic of forest ecosystems because of the role of green leaves in controlling many biological and physical processes in plant canopies. Accurate LA1 estimates are required in studies of ecophysiology, atmosphere-ecosystem interactions, and global change. The objective of this paper is to evaluate LA1 values obtained by several research teams us...
متن کاملThe computation of foliage clumping index using hemispherical photography
Hemispherical photography (HP) is extensively used for both canopy architecture such as leaf area index (LAI), and solar radiation regime determinations under forest canopies. This is done mainly by assuming that foliage elements occur in a spatially random manner. However, the majority of world forests occur in heterogeneous ecosystems and topography with rather complex canopy architecture. To...
متن کاملCharacterization of radiation regimes in nonrandom forest canopies: theory, measurements, and a simplified modeling approach.
We used field measurements and Monte Carlo simulations of canopy gap-size distribution and gap fraction to examine how beam radiation interacts with clumped boreal forest canopies of aspen (Populus tremuloides Michx.), black spruce (Picea mariana (Mill.) B.S.P.) and jack pine (Pinus banksiana Lamb.). We demonstrate that the Beer-Lambert law can be modified to accommodate transmission of radiati...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Remote Sensing
سال: 2018
ISSN: 2072-4292
DOI: 10.3390/rs10071153