Leaf Area Index
The leaf area index (BFI, English LAI Leaf area index ) is a key variable in the calculation of global climate scenarios (carbon dioxide output of the plant ) and the assessment of the ecological structure of, for example grasslands. However, the leaf area index also describes the influence of agricultural, forestry and natural vegetation on runoff generation.
Definition
The leaf area index is defined as the area per sheet bottom surface, BFI A = ( sheet ) / A ( bottom ) (dimensionless).
This leaves one side are counted and projected needle leaves on the ground. A BFI between 0 and 1 therefore means that there is less leaf area on a unit floor area. When BFI = 1, the areas are equal, and the BFI > 1 more leaf surface is provided as the bottom surface underneath.
Examples:
Special
To what extent leaves intercept rain depends on the type of plants, the density, the season and the cultivation method. This effect determined about it how much water reaches the bottom or previously lost as the initial loss for wetting and evaporation. The amount of water that evaporates before it touches the ground, it is called interception. This is particularly in low rainfall areas of importance, because there the dilated growing narrow-leaved varieties is advantageous.
Indirectly, the rain shadow of the leaves acts but also promotes the infiltration because it mitigates the silting of the topsoil.
In general, the BFI is more generally binding, the more uniform are the stocks. Plantations and agricultural crops can be so relatively accurately on table values to estimate, however, the BFI varies from natural forests in many areas, and must be calibrated in each case by measurements.
Leaf area density
The leaf area density ( LAD) is calculated from the LAI by this is divided by the inventory level. Looking at individual component layers, the LAD is clear from the LAI per cubic meter ( m² / m³). The LAD is interesting in that it can provide conclusions on the light profile in stocks.
See also: gas exchange, soil temperature, torque Earth