Leaf Area Index (LAI), which is used as a measure in hundreds of studies on forests, crops, climate and the environment, is calculated as
half the area of all leaves per unit area of ground
. It is measured as the leaf area (m2 ) per ground area (m–2) and is unit-less.
How is LAI calculated?
Leaf area index (LAI) is a measurement of development of canopy at a given time. It can be quantified by the formula
LAI= [Leaf area (m2)/Ground cover (m2)]
.
How does LAI work?
LAI can be determined directly by
taking a statistically significant sample of foliage from a plant canopy
, measuring the leaf area per sample plot and dividing it by the plot land surface area. Indirect methods measure canopy geometry or light extinction and relate it to LAI.
What is the range of LAI?
Clumping and spatial sampling
For example, in row crops, LAI can range from
0 to 2-3 within a distance of 1 meter
. Even in forests and other natural canopies, variable tree spacing, branching characteristics, and leaf arrangement on stems cause clumping.
Why is LAI important?
Importance. The leaf area index (LAI) is an important parameter in plant ecology. Because it
tells how much foliage there is
, it is a measure of the photosynthetic active area, and at the same time of the area subjected to transpiration. It is also the area which becomes in contact with air pollutants.
How do you find leaf area?
- Direct measurements: This involves taking the length and width of a leaf and using weighted regression equations for each species to get the leaf area. …
- Millimeter graph paper method: Here a leaf is taken and traced over graph paper, and the grids covered by the leaf are counted to give the area.
How is leaf area measured in ImageJ?
- Open ImageJ.
- Download here.
- Select the image you want to measure.
- Measure a known length to set the scale.
- Set the scale.
- Convert to 8-bit.
- Adjust the threshold.
- Fill in these white pixels.
What is Lai in remote sensing?
The ability to accurately and rapidly
acquire leaf area index
(LAI) is an indispensable component of process-based ecological research facilitating the understanding of gas-vegetation exchange phenomenon at an array of spatial scales from the leaf to the landscape.
What is a Ceptometer?
Ceptometer is
an instrument that measures the above and below canopy photosynthetically active radiation (PAR) and calculates LAI based on the ratio of the two
. … A large number of publications is available about the in-situ measurement of the LAI of field crops with various devices including ceptometers.
How do you calculate leaf area per plant?
Leaves were numbered from the top of the plant (i.e., flag leaf = leaf #1), and individual leaf areas were calculated by the formula:
A = (L) (W) (0.75)
, where leaf area, L _~ leaf length, and W = maxiinum leaf width. Actual leaf area/plant was obtained by summing areas of in- dividual leaves on each plant.
What is leaf shape coefficient?
The shape coefficient (slope of Model 3) can be described by a shape
between an ellipse (0.78) and a triangle (0.5) of the same length and maximum width
. Our shape coefficient (0.68) agreed closely with those calculated for other fruit trees. Values of 0.59 have been reported for Vitis vinifera L.
Who proposed leaf area index?
Introduction. Leaf Area Index (LAI) was defined by
Watson (1947)
as the total one‐sided area of leaf tissue per unit ground surface area. According to this definition, LAI is a dimensionless quantity characterizing the canopy of an ecosystem.
What is canopy architecture of trees?
A tree has a stem and a crown of branches that bear leaves, flowers, and fruits
. … A collection of these crowns creates the canopy (See Figure 1). Vertical structure is formed because trees and shrubs in a forest will have different heights. So, two or more layers of tree crowns can be found in forests.
What is the meaning of leaf area?
Leaf area index is defined as
the projected area of leaves over a unit of land (m2 m−2)
, so one unit of LAI is equivalent to 10,000 m2 of leaf area per hectare.
What is RGR in agriculture?
Relative Growth Rate
(RGR) takes into account the original difference in size of plants, which may have a significant influence on the increase in dry mass, and also the different performances due to the ageing of plants. RGR = mg g
– 1
day
– 1
(g is the existing mass of the plant)
How do you calculate leaf weight?
Specific Leaf Weight (SLW) is one of the few morphological characteristics of plants that shows large changes over the course of a single day. This value, calculated
by dividing the dry weight of leaves by their surface area
, makes SLW one of the easiest components of growth to measure.
