6.12　Survey of Distribution of Forest Trees

6.12.1　Where the lines cross over forests，a special survey on the distribution of forest trees shall be carried out.

6.12.2　Where the lines cross over trees，the boundaries shall be surveyed，and the names，categories，density，current breast-height diameter，and current growth height shall be indicated.

6.12.3　Aerial survey should be used for surveying the boundaries of forests and section line of tree heights，and total station shall be used for the check survey of tree heights.

6.12.4　The names，categories，density，current average breast-height diameters，and scope of trees shall be investigated and surveyed in the field，and sampling method may be used to obtain the average values.The data obtained through investigation and survey shall be indicated on the plans and sections.

6.12.5　The density may be expressed in the unit of"number of trees/m2"，the current growth height may be expressed in H with unit of m，and the breast-height diameter may be expressed in D with the unit of cm.