Increasingly, forests play a very important role in combating global warming through sequestering greenhouse gases, especially carbon dioxide. They can be a sink or source of atmospheric carbon dependent on forest management regimes (FMR). To be a permanent sink of carbon as well as a perpetual source of supply for various wood and non-wood products and services, the most reliable information is required for sound forest management planning. Through almost three decades of political instability, forestry management activities in Cambodia were completely suspended, most of the forestry professionals were killed and related documents were burned, resulting in large-scale illegal logging, forest degradation and deforestation. One of the current issues was the lack of information on forest stand structures, growth and yields, and harvest potentials of all forest types in Cambodia, which makes it difficult to apply the appropriate FMR in Cambodia. Therefore, the objective of this study was to provide comprehensive information on forest stand structures, growing stock and harvest potentials of the three commercially valuable forests (evergreen, mixed and deciduous forests), which could form the basis for management decision making. A supplementary study on volume estimation, with the help of volume equations, and growth and yields was also conducted. Data for this study was obtained from the latest forest inventory conducted in Sandan district in 1995-'96 by FAO in cooperation with the Department of Forestry and Wildlife, Cambodia.

Cambodia has 10.6 million ha of forest cover or 58% of the country's total land area. Representing 90% of total forest area, the three major forest types were granted to logging concessions with 25-99 years contract duration. Data of 42 inventoried clusters in Sandan forests were analyzed, and the results showed that, on average for all trees with DBH (diameter at breast height) greater than 5 cm in evergreen forest, 1,105.5 trees/ha and 235.2 m^3/ha were recorded for stem density and stand volume, respectively. Based on selective felling with a 30-year cycle, the harvest potential of this forest is theoretically about 50 m^3/ha, of which dipterocarp, non-dipterocarp and unknown (species that were unidentified during inventory; most them are not commercial) shared 72%, 7% and 21%, respectively. For mixed forest, 695.0 trees/ha and 167.9 m^3/ha were recorded. The harvest potential for mixed forest is 28 m^3/ha, of which dipterocarp, non-dipterocarp and unknown species accounted for 43%, 33% and 24%, respectively. For deciduous forest, 626.4 trees/ha and 178.1 m^3/ha were recorded. The harvest potential of deciduous forest is 35 m^3/ha, of which dipterocarp, non-dipterocarp and unknown shared 8.3%, 80.6% and 11.1%, respectively. Dipterocarp species of Chheutiel Bangkouy (Dipterocarpus turbinatus), Phdeak (Anisoptera glabra) and Chramas (Vatica astrotricha) are dominant in the three forest types, and thus are the species likely to be harvested.

By comparing harvest potentials in these forests to actual harvest volumes in Southeast Asia, a FMR for Cambodia was proposed. Selective felling with a 30-year cycle is appropriate for forests in Cambodia, and the annual allowable cuts (AAC) should be set at 40 m^3/ha (17.0 % of growing stock), 25 m^3/ha (14.9% of growing stock) and 30 m3/ha (16.8% of growing stock) for evergreen, mixed and deciduous forests, respectively. These AAC should be revised after the first felling cycle (30 years) when new information of growth and yields becomes available. Protection of natural regeneration will reduce the management cost. Therefore, leaving enough mother trees, and protection of seedlings and saplings in the forests are required. Further research on potential wood utilization of unknown tree species and non-timber forest products should be encouraged. To ensure long-term sustainable forest management, land use policy, clear boundary demarcation on the map and in the field, cooperation and political commitment should be in place.