Ecological Studies of Tropical Seasonally Dry Forest in Continental Southeast Asia: A Review using Thailand as a Case Study

Pongsak Sahunalu



Tropical seasonally dry forest in Continental Southeast Asia has a prominent and similar importance to the region as does tropical rain forest. As there is broad encouragement to protect tropical forest to maintain global biodiversity and remedy global warming, major parts of this forest type are included in the protection system of all countries in Continental Southeast Asia. However, it has been less studied, particularly by ecologists, compared to the tropical wet forest type especially in this region compared to those forests in South and Central America. Ecological studies covering its past and present natural distribution, area cover, nomenclature, and some important aspects were examined using Thailand as a case study as representative of the Continental Southeast Asian region. The history of Thai-Japanese collaborative ecological studies in seasonally dry forests in Thailand is also described briefly. This broad forest community type in Thailand consists of seasonally dry forests of Mixed Deciduous or Monsoon Forest and Dry Evergreen or Seasonal Evergreen Rain Forest with variants occurring in small valleys and along stream banks called Gallery Forest and Dry Dipterocarp or Deciduous Dipterocarp Forest. About 35 topics were found to have been intensively studied and published in scientific papers for these three forest community types in various locations in Thailand. Some of these studies are likely to have not fully covered all ecological aspects and all the details of each approach. Future research needs to fill knowledge gaps and to cover all interesting ecological as well as other related aspects that this study has identified to stimulate interested researchers in this region as well as other scientists to pay more attention to this forest type in the tropics, particularly in Thailand. Trans-boundary studies in neighboring Continental Southeast Asian countries are also encouraged.