Is the leaf area meter suitable for measuring the leaf area of ​​the needles?

Is the leaf area meter suitable for measuring the leaf area of ​​the needles?
Using a hand-held leaf area meter to measure the leaf area of ​​plants, this measurement method is more accurate and the field of application is comparatively wide. However, when using this measurement method to make measurements, care must be taken not to use it for a long time so as not to introduce errors. At the same time, during the measurement process, the light-transmitting plate must be kept clean at all times, otherwise it will affect the measurement accuracy, but it is not easy to use this measurement method to measure the leaf area measurement of the needle leaves, generally using the volume method. measuring.
The conifers are usually two, three, or five, and different tree species have different cross-sections. Therefore, the conversion formula of the conifer area mainly considers its own anatomical structure. At this time, it can be converted using the empirical formula method. Get the leaf area index. The empirical formula is as follows:
(1) Spruce

(2) Two needles loose
S=π×L×(d+d1) /2+2dL
(3) Three-pin pine
S=(2πR/3+R+R)×L×3
(4) Five-pin pine
S = [(2πR /5) + R+R] × L × 5
Where: S: leaf area; a, b: side length of the diamond; S: area of ​​a needle leaf; L: length of the needle; D: width of the flat surface of the needle; d1: thickness in the direction perpendicular to the flat surface; R: average needle diameter.
The volume method is a common method for determining the area of ​​conifer leaves in recent years. This measurement method is applicable to the measurement of the leaf area of ​​any type of needle, and its formula is as follows:

Where: A: leaf area; V: needle volume (determined by drainage method); n: number of needles per bunch; L: needle length.
Compared with other formulae for measuring the area of ​​needles, this method can be applied to the needle area with different cross-sections, and its operation is simple and easy to popularize. Portable leaf area meters have some limitations in the measurement of needles, but they are used in other places and areas.

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