Effects of Silvicultural Alternatives on Model-Based Financial Evaluation of Teak ( Tectona grandis L.) Farm Forestry Management for Small-Scale Farmers in Northeast Thailand

Abstract

Teak (Tectona grandis L.) plantation management is said to be profitable, but small-scale farmers with teak plantations need to find appropriate and effective choices for plantation management because of their small plots. There have been few studies on how combinations of site quality, ro-tation and plant spacing affect financial evaluations of teak plantation management quantitatively. In this study, we introduced the yield table for teak plantations in Northeast Thailand, and inves-tigated the effects of site quality with rotation (15-year and 20-year) and spacing (2 m × 4 m and 4 m × 4 m) on the financial evaluation of teak plantation management using discounted cash flow analysis. The equivalent annual incomes (EAI) and benefit/cost ratios (BCR) were negative and <1, respectively, at site indexes (SI) of 14 and 18, but increased ~2 -3 times as SI rose from 22 (site of medium quality) to 26 and 26 to 30. The 20-year rotation was generally preferable to the 15-year one, especially at SI 22. At SI 30, 2 m × 4 m was more profitable than 4 m × 4 m for both rotations, but at SI 22, 20-year rotation with 4 m × 4 m was the most profitable, followed by 20-year with 2 m × 4 m.