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 ...

Leaf area index is one of the most important parameters in ecological and environmental studies. This paper presents a method for single leaf area measurement based on the counting of the leaf pixels in digital leaf image. Initially, the target leaf is put on a piece of white paper on which four endpoints of an equal-length and orthogonal cross are printed. A background color threshold is then ...

grain yield loss in rice (oryza sativa l.) caused by blast disease, magnaporthe grisea (hebert) barr, is a major concern of rice growers worldwide. blast is considered as the most injurious disease of rice in iran, resulting in severe loss especially to susceptible rice cultivars. in order to assess yield loss caused by blast pathogen and develop an appropriate model, different disease onsets a...

Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO(2)]) and elevated ozone concentration ([O(3)]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work ...

The crown structure of Eucalyptus nitens (Deane & Maiden) Maiden 6 years after thinning, and the development of stand leaf area index both immediately and 6 years after thinning, were investigated. Thinning did not alter branch angle, branching density or the relationship between branch size and branch leaf area. However, larger branches were found in the lower crown of thinned trees and the in...

The potential sensitivity of ecological models to differences in soil temperature and soil water from land-surface models was evaluated by using model output from the PILPS land-surface model comparison. Simulated soil water and temperatures from the land-surface models were used to calculate the abiotic decomposition factor (ADF). ADF is used by ecosystem models to directly control microbial a...

Leaf area index (LAI) is an important essential biodiversity variable due to its role in many terrestrial ecosystem processes such as evapotranspiration, energy balance, and gas exchanges as well as plant growth potential. A novel approach presented here is the retrieval of LAI using thermal infrared (8–14 μm, TIR) measurements. Here, we evaluate LAI retrieval using TIR hyperspectral data. Cano...

Leaf area index (LAI) can be measured either directly, using destructive methods, or indirectly using optical methods that are based on the tight relationship between LAI and canopy light transmittance. Third, innovative approach for LAI measuring is usage of remote sensing data, especially airborne laser scanning (ALS) data shows itself as a advisable source for purposes of LAI modelling in la...

Leaf area index, defined as one half the total (all sided) leaf area per unit ground surface area [1], is a key vegetation structural parameter used in most ecological, hydrological and meteorological models to describe physical and biological processes associated with vegetated surfaces and their interaction with the atmosphere. The accuracy of existing global LAI parameters is not yet satisfa...