TEAK PLANTATIONS IN NILAMBUR - Kerala Forest Research Institute

identified. Site quality class I is the highest class and IV is the lowest. The site
quality is determined based on the top height of the crop.
All India yield tables of teak show seven site quality classes including
fractional quality classes and the estimated yield from thinning and final
felling at five-year intervals. In the present study the mean ages obtained for
thinning are 6, 8, 13, 19,28 and 41 years. As the expected yields for the above
years are not available in the All India Yield Tables, the corresponding
expected yields have been interpolated and presented in Appendix 5. Similarly
the expected yield in final felling are also available in the yield tables only at
five year intervals. The expected final felling yields for the years in between
have been interpolated and given in Appendix 6. From these two Appendices
the yields expected in thinning and final felling for the mean age of different
operations in different site quality classes are shown in Table 3.5. In the first
mechanical thinning (lM), the expected yield in site quality I at the age of 6
years is 22.32 m 3 ha -1 , whereas in site quality IV it is only 1.47 m 3 ha-1. Similarly
in site quality I, the expected yield at final felling at the age of 53 years is
271.63 m 3 ha-1 and that in site quality IV is 68.71 m 3 ha -1 .
The expected total yield for different site quality classes is also available only
in five year intervals. As the mean rotation age for Nilambur Divisions is 53
years, the expected total yields and MAI for selected years are interpolated
and shown in Table 3.6. For site quality I plantation, the expected total yield
is 520 m 3 and MAI at 53 years 9.84 m 3 ha -1 year -1 . For site quality IV
plantation, the expected total yield at the same age is 112 m 3 and MAI is
2.1 3m 3 ha-1 year -1 .
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