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kb:lad [2012/08/15 22:28] – enviadmin | kb:lad [2012/08/15 22:53] – enviadmin | ||
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====== Obtaining Leaf Area Density Data ====== | ====== Obtaining Leaf Area Density Data ====== | ||
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The **Leaf Area Density (LAD)** is the portion of leaf surface ($m^2$) within a volume of air ($m^3$). The formal unit is | The **Leaf Area Density (LAD)** is the portion of leaf surface ($m^2$) within a volume of air ($m^3$). The formal unit is | ||
$$ \frac{ \text{Leaf surface } (m^2)}{ \text {Reference volume } (m^3)} $$ | $$ \frac{ \text{Leaf surface } (m^2)}{ \text {Reference volume } (m^3)} $$ | ||
- | In ENVI-met, like in most other models, the LAD is counted **one-sided** which means that only one side of the leaf is counted as active surface area. This accounts to the fact, that most plants only have stomata | + | In ENVI-met, like in most other models, the LAD is counted **one-sided** which means that only one side of the leaf is counted as active surface area. This accounts to the fact, that most plants only have [[wp> |
===== Objective ===== | ===== Objective ===== | ||
- | One of the most frequently asked questions is "How do I get an LAD profile for my plant?" | + | One of the most frequently asked questions is "//How do I get an LAD profile for my plant?//" |
First, I have to admit that the original LAD profiles provided by ENVI-met are rather hand made and based on only a few reference profiles. \\ | First, I have to admit that the original LAD profiles provided by ENVI-met are rather hand made and based on only a few reference profiles. \\ | ||
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==== Methodology 1b: Leaf collection | ==== Methodology 1b: Leaf collection | ||
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This methode is straight forward and has certain drawbacks for the tree. You can define your reference volume (1 cubemeter or less) and then collect all the leafs that are inside this volume. You place them on a sheet of paper as close as you can get them and then calculate the leaf surface area. There are also more sophisticated methods available using digital image processing. But as we talk about rude methods here, we restrict outselves to the very basic approach... | This methode is straight forward and has certain drawbacks for the tree. You can define your reference volume (1 cubemeter or less) and then collect all the leafs that are inside this volume. You place them on a sheet of paper as close as you can get them and then calculate the leaf surface area. There are also more sophisticated methods available using digital image processing. But as we talk about rude methods here, we restrict outselves to the very basic approach... | ||