Under this system the minimum cutting limit is
fixed that is not less than 45 cm diameter at breath height (dbh) for dipterocarp forest
and not less than 50 cm (dbh) for non-dipterocarp forest .
In order to determine the appropriate minimum cutting limits under the SMS, a
pre- felling forest inventory is carried out to provide reliable estimates of the
population for all tree species having 5 cm dbh and above, and tree species having a dbh
of less than 5 cm but having a minimum height of 15 cm. Physiographic features are also
recorded which include slope, elevation, soil types and river systems.