Timber Volume Assessment of Rubber Trees: A Case Study of the Kanchanadit Plantation, Surat Thani Province

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Chirachaya Khunsathien
Patsi Prasomsin
Kritsadapan Palakit

Abstract

            Timber volume table is one of many forest management tools which are used for a rapid and easy standing tree volume assessment without cutting the trees down. The objectives of this study were to construct a local merchantable volume, and to assess the amount of wood in rubber trees (Hevea brasiliensis) at the Kanchanadit plantation, Surat Thani province. Forest inventory was done by a systematic strip sampling to classify the trees in various diameter classes. A local merchantable volume table was constructed from 40 selected trees covering all diameter classes of trees in the plantation. Diameter at 170 centimeters above ground level, merchantable height, total height, and the number of merchantable logs of sample trees were recorded. The merchantable volume of sample trees was then calculated by using Huber’s formula. Multiple regression analysis was done with various model equations to select the optimal equations that explained the best statistical relationship between the merchantable volume and independent variables. The optimal equation for estimating the merchantable volume of a rubber tree was determined as:  Log V = (-3.920) + 1.986 log D + 0.626 log Hm, where V is the merchantable volume (inside bark) in cubic meters, D is the diameter at 170 centimeters above ground level, and Hm is the merchantable height in meters.


                These equations were then used to construct merchantable volume tables and to test the differential percentage between the volume of trees as calculated by Huber’s formula and the selected equations. The result showed that the error in tree volume estimation using these equations was 8.47%. For assessing the average merchantable volume of rubber woods in plantation of 648.95 rai, it was found that the volume was 4.99 cubic meters per rai, and the total merchantable volume was 3,239.41 cubic meters.


Keywords:  Timber volume table, Timber volume Assessment, Rubber Tree

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How to Cite
Khunsathien, C., Prasomsin, P., & Palakit, K. . (2021). Timber Volume Assessment of Rubber Trees: A Case Study of the Kanchanadit Plantation, Surat Thani Province. Thai Journal of Forestry, 40(1), 95–107. Retrieved from https://li01.tci-thaijo.org/index.php/tjf/article/view/248719
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