TEAK PLANTATIONS IN NILAMBUR - Kerala Forest Research Institute

3. PRODUCTIVITY OF TEAK PLANTATIONS
Yield from teak plantations is obtained from a series of thinning operations
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and final felling. The different types of work in teak plantations are first
mechanical thinning (IM), second mechanical thinning (2M), four silvicultural
thinnings (1S to 4S) and final felling (FF). Total yield is the sum of yields
from periodic thinnings and final felling. Productivity is measured in terms of
total yield or mean annual increment (MAI). When total yield is divided by
the age of final harvest, the rotation age, MAI is obtained.
In this section, productivity of teak plantations in Nilambur North and
Nilambur South Forest Divisions, based on actual yields is analysed.
3.1 Productivity in Nilambur Divisions
3.1.1 Yields in different periods
Average yield obtained in different operations during the periods 1967 to
1981, 1982 to 1994 and for the entire period (1967 to 1994) was computed
and presented in Tables 4.1, 4.2 and 4.3 respectively. The mean age of
thinnings and final felling are different for each period. The age range within
which each set of operations was carried out is also shown. Total area refers
to the total area of plantations for which the yield data were obtained. When
yield data from more than one operation are available, the area is added again
so that the total area is more than the existing plantation area. It may be
noted that data from different operations in the same plantations are
accounted here separately so that 372 plantations only indicate that the data
from 372 thinning and final felling operations have been included in the
analysis.
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