in order to study the effect of elevation on quantitative and qualitative characteristics of the humid forests of guilan shafaroud, series 17, 16 and 7 were selected that fall in to three height classes; class 1 (‏less than 500 m), class 2 (‏500 – 1000 m) and class 3 (‏1000 – 1600 m). in height class 1, 2 and 3 sample plots were determined as 4, 15 and 20 respectively and each sample plot was 0...

The climate of the Alaskan Arctic is warming more rapidly than at any time in the last 400 years. Climate changes of the magnitude occurring in high latitudes have the potential to alter both the structure and function of arctic ecosystems. Structural responses reflect changes in community composition, which may also influence ecosystem function. Functional responses change the biogeochemical c...

Radiation reflected from vegetation canopies exhibits high spatial variation. Satellite-borne sensors measure the mean intensities emanating from heterogeneous vegetated pixels. The theory of radiative transfer in stochastic media provides the most logical linkage between satellite observations and the three-dimensional canopy structure through a closed system of simple equations which contains...

An analytical expression for the bidirectional reflectance field of a vegetation canopy is derived from physical and geometrical considerations of the transfer of radiation through a porous medium. The reflectance pattern is shown to depend explicitly on the optical properties of the scatterers (for example, leaves), and on the structural parameters of the canopy, such as the statistical distri...

Rainforests represent the epitome of structural complexity in terrestrial ecosystems. However, measures of three-dimensional canopy structure are limited to a few areas typically < 1 ha with construction crane or walkway/platform access. An innovative laser pro® ling system, the Laser Vegetation Imaging Sensor (LVIS), was used to map canopy structure (i.e. based on height and vertical distribut...

We quantified structural attributes in three alluvial flat old-growth coast redwood stands. Tree size parameters and occurrences of distinctive features (e.g., burls, goose pens) were similar between stands. Occurrence of distinctive features was greater among larger trees. Tree sizefrequency distributions conformed to a reverse-J diameter distribution. The range of tree sizes was similar betwe...

The angular dependence of satellite-measured canopy reflectance has been shown to contain information on the structure of vegetated surfaces. The aim of the research was to explore the angular variability of spectral indices and to compare the suitability of angular indices and traditional vegetation indices for retrieval of forest structural attributes using Chris/PROBA data. With spruce the l...

The contribution of the understorey vegetation to the spectral reflectance from the top of a forest canopy was investigated by the use of a forest canopy reflectance model. Detailed field data, i.e. forest leaf area index (LAI), tree structural parameters like the height, diameter and crown length of the trees, and the composition, distribution and reflectance of the forest floor, was collected...