1. Density

It is the mass per unit volume. Specific density is ratio of density of any substance with water. The unit is kg/m³. Volume as well as weight shrink due to dryness. So, there is moisture content in fresh weight, it is expressed in %. Density varies from pith to sapwood. It also varies from stump to top. So, the density of trees varies from part to part.

2. Moisture content

It is the moisture in wood. But also in all parts of tress. The moisture content varies from species, geographical areas. It also varies with age and physical condition of tress. So, it is difficult to measure. It varies in broadleaf and conifer. Moisture content varies up to 151.2 % depending on time of harvest.

Moisture content =((Fresh wt-dry wt)/Fresh wt)*100%

3. Bark

According to Kodai Kanal,

(Bark weight)^1/2= a+b*D

Where, a constant, b coefficient, D diameter at breast height

Factors affecting the bark % in wood:

• Species,
• geographical condition
• Diameter of the tree

How to dry?

• Generally air dry but 12% remaining
• In Lab, there may be less moisture (400°C till show the constant weight)