نتایج جستجو برای: canopy structure

تعداد نتایج: 1579939  

Journal: :IEEE Trans. Geoscience and Remote Sensing 2001
Oleg Panferov Yuri Knyazikhin Ranga B. Myneni Jörg Szarzynski Stefan Engwald Karl G. Schnitzler Gode Gravenhorst

This paper presents empirical and theoretical analyses of spectral hemispherical reflectances and transmittances of individual leaves and the entire canopy sampled at two sites representative of equatorial rainforests and temperate coniferous forests. The empirical analysis indicates that some simple algebraic combinations of leaf and canopy spectral transmittances and reflectances eliminate th...

Journal: :Journal of theoretical biology 2002
Niels P R Anten

Using an analytical model, it was shown that for a given amount of nitrogen in the canopy of a stand (N(T)), there exists an evolutionarily stable leaf area index (ES-LAI), and therefore an evolutionarily stable average leaf nitrogen content (n(ES)(av);n(ES)(av) =N(T)/ES-LAI), at which no individual plant in the stand can increase its photosynthesis by changing its leaf area. It was also shown ...

2007
M. Schlerf C. Atzberger

Studies that compare modelled reflectances with satellite-measured reflectances for different wavelengths and view angles are still rare. We compared model outputs from three different canopy reflectance models (SLC, FRT and INFORM) with satellite measured reflectances (Chris/PROBA). Comparison of the simulated directional reflectances reveals general agreement but also some differences among t...

Journal: :Remote Sensing 2015
Ross A. Hill Shelley A. Hinsley

Structure is a fundamental physical element of habitat, particularly in woodlands, and hence there has been considerable recent uptake of airborne lidar data in forest ecology studies. This paper investigates the significance of lidar data characteristics when modelling organism-habitat relationships, taking a single species case study in a mature woodland ecosystem. We re-investigate work on g...

Journal: :Remote Sensing 2017
Yuwei Chen Teemu Hakala Mika Karjalainen Ziyi Feng Jian Tang Paula Litkey Antero Kukko Anttoni Jaakkola Juha Hyyppä

Microwave Radar is an attractive solution for forest mapping and inventories because microwave signals penetrates into the forest canopy and the backscattering signal can provide information regarding the whole forest structure. Satellite-borne and airborne imaging radars have been used in forest resources mapping for many decades. However, their accuracy with respect to the main forest invento...

Journal: :Frontiers in Ecology and the Environment 2023

Large-scale, globally consistent characterizations of the Earth's terrestrial ecosystems are a critical component international conservation and ecological monitoring initiatives. To help coordinate operationalize these efforts, Convention on Biological Diversity (CBD) Group Earth Observations Biodiversity Observation Network (GEO BON) have devised list essential biodiversity variables (EBVs) t...

Journal: :Tree physiology 2014
Adam P Coble Molly A Cavaleri

Leaf mass per area (LMA, g m(-2)) is an essential trait for modeling canopy function due to its strong association with photosynthesis, respiration and leaf nitrogen. Leaf mass per area, which is influenced by both leaf thickness and density (LMA = thickness × density), generally increases from the bottom to the top of tree canopies, yet the mechanisms behind this universal pattern are not yet ...

Journal: :Remote Sensing 2017
Jucai Li Wenjie Fan Yuan Liu Gaolong Zhu Jingjing Peng Xiru Xu

In contrast to herbaceous canopies and forests, savannas are grassland ecosystems with sparsely distributed individual trees, so the canopy is spatially heterogeneous and open, whereas the woody cover in savannas, e.g., tree cover, adversely affects ecosystem structures and functions. Studies have shown that the dynamics of canopy structure are related to available water, climate, and human act...

Journal: :Remote Sensing 2010
Dimitry Van der Zande Jan Stuckens Willem W. Verstraeten Bart Muys Pol Coppin

Light availability inside a forest canopy is of key importance to many ecosystem processes, such as photosynthesis and transpiration. Assessment of light availability and within-canopy light variability enables a more detailed understanding of these biophysical processes. The changing light-vegetation interaction in a homogeneous oak (Quercus robur L.) stand was studied at different moments dur...

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