The Mo Singto Research Site
The first research to be carried out at the Mo Singto research site was studies of the social behavior, communication, and ecology of gibbons (Hylobates lar). The Mo Singto site, 0.5–1.0 km from the park headquarters, is covered with good canopy forest and has a relatively dense population of gibbons in it. Since 1980, researchers from Germany, U.S., U.K. and other countries, as well as Thailand, have conducted their thesis projects there. The lack of a published botanical guide to the flora of Khao Yai, however, made studies of gibbon diet rather difficult, as every year new species of fruit of trees and lianas would be collected but could not be identified. In 1996, Mahidol researchers decided to establish a permanent forest dynamics plot over the home range of the main gibbon study group, which was well habituated to observers. This project was supported by the Biodiversity Research and Training Program under BIOTEC, and was carried out by researchers associated with Mahidol University’s Institute of Science and Technology for Research and Development.
In 2001 the principal investigator, Prof. Warren Y. Brockelman of Mahidol University, joined the BIOTEC Central Research Unit as a part time researcher and helped establish the Ecology Laboratory there. BIOTEC provided labs for plant specimen processing and also data processing and geographic information system (GIS) development, in collaboration with the GIS research group under Ajarn Tasnee Anaman and Dr. George Gale. The plant voucher specimen collection initially stored at the ISTRD, Salaya campus of Mahidol University, was completely moved to the BIOTEC Central Research Unit, now its permanent home.
The first tree census of the Mo Singto plot, including all stems >10 cm diameter, on the 30-hectare plot was completed in the 2000–2001 dry season, and soon after a census of lianas or woody vines over 3 cm in diameter was also done. The total number of tagged, measured and mapped trees was 16,375 and the total number of lianas was 9,510. The liana census was particularly difficult because specimens of reproductive material for identification had to be retrieved from the canopy, and the liana flora of the park was completely unknown previously. The tree census included 200 species on the plot and the liana census about 120 species. About 40 additional liana species have been collected in other parts of the park surrounding the plot. It is proving to be possible to identify liana species from vegetative characteristics alone: the shape and texture of the stem, branching pattern, color of the sap and inner bark and wood, etc. A guide will be prepared for field identification of lianas, which will greatly facilitate future inventories and also the search for natural products, as very few lianas have been examined for useful chemicals.
A new census of all trees and shrubs down to 1 cm in diameter at breast height was carried out in the dry season of 2004–2005. This involved mapping of over 100,000 additional stems and storing them in a database.
A number of important ecological questions are being investigated on the Mo Singto Plot. The most important questions concern the long-term dynamics of the plant community and its responses to climate change, particularly to global warming. One interesting question is why some trees are common, and many others rare. To help answer this question, we must understand the distribution and dynamics of each individual species on the plot. Evidence is accumulating that the tree community is not in a stable equilibrium, but is in a state of change and flux, with some species increasing and others declining.
In order to understand the dynamics of individual tree species, ecologists are investigating the dispersal and recruitment of the species on the plot to determine how their processes affect the demography of the species. Particular attention is being paid to species whose seeds are swallowed and dispersed by frugivores such as gibbons, deer, and birds. Dispersal mutualisms (interactions) play a vital role in determining the future of both plants and the animals that depend on them.
Smaller Research Plots
In addition to the Mo Singto Plot, which is 30 hectares in area, two smaller plots of 4 hectares have been established by the Ecology Laboratory, are in Sam Lan Waterfall National Park near Saraburi, the other is Bala Wildlife Sanctuary in Narathiwat Province in the South. Both plots are located in forests that have been selectively logged in the past, but are now regenerating back into mature forest. The objectives of these plots are to evaluate increase in biomass and biodiversity, and the role of each species.
Future Research Directions
The variety of important research topics that can be carried out on permanent research plots like the one at Mo Singto is astounding. The detailed study of interactions between plants and animals, and also fungi and microbes, will eventually lead to discovery of many new products. Such interactions are largely governed by allelochemicals and nutrients, which either facilitate or inhibit interactions. By investing in long term research plots we will enable identify all the organisms present and explore their relationships. It is a long term investment in biotechnology that can pay off in many different ways.
The establishment of new long term research sites is justified in terms of biodiversity inventory, monitoring of the environment, and research on communities and ecosystems. Several new sites are now being established by the Ecology Laboratory team. This includes one in Saraburi in the Sam Lan Waterfall National Park and another in Hala Bala wildlife sanctuary in Narathiwat Province. These will be smaller (4 ha) plots in previously disturbed and partly logged forest, and one of the objectives is to determine how fast the forest is regenerating in these sites. The role of seed dispersing animals in regeneration will also be explored. Plots in these sites also have a strong educational value, and the role of databases and GIS maps in educational activities is also being explored.
A white-handed gibbon (Hylobates lar) at the Mo Singto research site.
Gnetum macrostachyum is one of the gibbon foods.