III. Estimating Biomass in plantation

III-1 Estimating Total Dry Weight of each sample tree

Total dry weight (*TDW*) of each organ of a sample tree can be calculated from its total fresh weight (*TFW*), the fresh weight of its organ sample (*SFW*) and its dry weight (*SDW*).

[Boughs, Leaves, Twigs]

[Trunk, Bark]

III-2 Estimating Biomass using allometric relation

[Allometric relation]

Biomass by each organ in the site can be estimated from the allometric relations between DBH and the total dry weight (*TDW*) of each organ obtained from sample trees (Fig 4). Allometric relation is expressed in the following equations;

or,

where*a* and *b* are coefficients. The coefficients can be applied to estimating biomass of other sites of the same species near the test site.

or,

where

(Fig 4 Example of the allometric relation between DBH and Total Dry Weight of stem (TDW_{stem}) obtained from sample trees.)

[Biomass]

Biomass per unit area is calculated as follows;

where,

*sumTDW* : the sum of the total dry weight of every standing tree in the target site (t dry matter)

*AREA* : the area of the target site (ha=10000m^{2})

*BM* : the biomass of the target site (t dry matter/ha)

In converting the dry matter to carbon unit, 0.5 is generally used as a conversion coefficient.

where,

In converting the dry matter to carbon unit, 0.5 is generally used as a conversion coefficient.

Mean annual increment (*MAI*, t dry matter/ha/year) is calculated as;

where*t* is the age of the target site.

where

III-3 Leaf Area Index (*LAI*)

where,

IV. Estimating Biomass in Bush or in Regenerated Vegetation

Total dry weight (*TDW*) of each organ can be calculated from total fresh weight (*TFW*), fresh weight of organ sample (*SFW*) and its dry weight of sample (*SDW*).

Then each biomass (*BM*; t dry matter/ha) is calculated as follows;

where,

*TDW*: Total dry weight of each organ (kg)

*A*: Plot area (m^{2})

where,

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