OPTIMISING TREE DIVERSITY AND ECONOMIC RETURNS FROM MANAGED MIXED FORESTS IN KALIMANTAN, INDONESIA

Abstract

This paper addresses the problem of optimising the management of uneven-aged forests under the dual objectives of economic returns and tree species and size diversity. Three models are developed: 1) Model I is aimed at maximising sustainable tree diversity; 2) Model II is formulated to maximise economic returns from harvesting while also ensuring sustainability of the stand; and 3) Model III is aimed at maintaining an exogenous level of tree diversity while at the same time maximising economic returns and ensuring the sustainability of the stand. The models are applied to an old-growth forest that contains trees belonging to the highly commercial family of species called Dipterocarpaceae located in the tropical forests of Kalimantan, Indonesia. Simulations based on the three models are used to examine some of the provisions and technical regulations contained in the Indonesian Selective Cutting System.