In order to preserve natural tropical forest resources, one tends to favour the establishment of forest reserves for conservation and plantations for the production of merchantable timbers. On the other hand, both conservation and production can be implemented in sustainable forest management systems. The development of such systems is hampered by the lack of accurate knowledge on indigenous forest ecology.
In the forest of Ban Pong near Chiang Mai in northern Thailand, research was conducted to reveal site characteristics and indicator species of deciduous forest types. Stratified random sampling plots were laid out in different forest stands. Stand parameters, vegetation composition and environmental variables were assessed and analysed by means of multivariate analysis techniques.
Deciduous forests in Thailand are of two main types: mixed deciduous and deciduous dipterocarp forest. Results of this study suggest that the latter should be subdivided into a xeric or dry phase, an intermediate phase and a moist or mesic phase. The differentiation of forest types is controlled by edaphic factors, first of all effective soil depth. In addition, human impacts, such as the annual burning of the ground layer, seem to affect soil, structure and species composition of the different deciduous forests. The indicators that were identified for the different phases are easily recognized and should be verified for further use in rapid ecological assessment of the deciduous forests in the region.