GROVITH PERFORMANCE OF LARGE DIAMETER RATIAN (Calamus) PLANTED UNDER PINE PLANTATIONS AT SINHARAJA BUFFERZONE

Abstract

Rattans can be considered as the most important non-timber forest product. Due to heavyexploitation from the wild, the resource is declining at an alarming rate. The present studyexamined the growth performance in terms of plant height, total lengths of stems,diameter, clump formation and number of live leaves and average growth rates of threelarge diameter rattan species, namely Calamus zeylanicus Becc., Calamus thwaitesiiBecc., and Calamus ovoideus Thw. ex Trim, planted under pine plantations in the bufferzone of Sinharaja, Sri Lanka. Four sites of rattan plantations in ages, 8, 9, 10 and 12 yearswere selected with each site consisting of five plots. Lengths of stems were estimated andstern diameter was measured without the sheath. Number of live leaves and stems in aclump were counted in each plant. Number of pine trees of each site was counted and soilanalysis was carried out to depict the site 9ualit'l.

The highest stem lengths were recorded in the oldest site and the highest mean heightrecorded afer 12 years was 20 m. Results showed that the height increases with the ageand the average growth rate decreases. The highest avera~e growth rate, 1.87 m per yearwas recorded in the 8 year old plantation and the lowest, 1.75 m was recorded in the 12year old plantation Average number of stems in a plant varies from 1 to 4 stems per plantin all four sites. Average diameter of stems i:l all sites was in the range of 1.8 to 2.1 ern,irrespective of the age of the plantation. The average number of leaves declined with theage of the plantation. In conclusion it is possible to say that although the stem lengthincreases With the age of the plantation, the average growth rate decreases. Average stemdiameter and number of stems in a plant have not shown' any relationship with the age.