Feature

Tropical Feast
By Kamol Sukin

Forestry officials and environmentalists have long been at loggerheads over the suitability of the eucalyptus tree for Thailand's reforestation programme. The forestry department favours the fast-growing eucalyptus on the grounds that mass planting will assist in the rapid recovery of the eco-system through introducing new forest tracts to key watershed areas.

While not disputing the rate of growth, environmentalists point out that the large-scale planting of eucalyptus forests destroys wild flora, thus preventing the diffusion of nutrients in the soil.

According to Dr Vilaiwan Anusarnsunthorn and Dr Stephen Elliott, lecturers in biology at Chiang Mai University (CMU) and leaders of the Forest Restoration Research Unit (Forru) attached to the university's faculty of science, the hmon hin (stone pillow) tree (rhamnaceae) is just one of 30 potential species identified that would meet the demand for rapid growth while not disturbing the ecological balance.

Says Elliott: ''The hmon hin grows at roughly the same rate as eucalyptus, reaching six metres in height within three years. One major asset is that the horizontal growth of the stem provides more shade than the eucalyptus and this, in turn, allows other species of saplings to thrive.''

But perhaps most important of all, Elliott explains, is that an area rich in hmon hin attracts several varieties of both birds and mammals which feed on the seeds of wild fruit, and through excretion promote the spread of plant life.

''This type of tree provides the basic framework for reforestation and reduces the need to plant hundreds of different species. By increasing soil fertility, the door is wide open for other flora to propagate. It is an efficient mechanism for accelerating the recovery of the forest eco-system. This method [of reforestation] has been very effective in Australia.''

Elliott is not proposing that the forestry department plants entire forests of trees belonging to the same family as the hmon hin. ''If we are to use this species as the framework or basis for eco-recovery, the tree must also be introduced in diversified forest tracts. That ensures that the conditions essential to speeding up the recovery process are created.

''But first we need to conduct a study in each area to confirm that the framework species we are proposing are appropriate to the site and beneficial to local flora. Our research has concentrated on more than 30 base species in the northern part of the country. Hmon hin is just one of our finds.''

The scientific name for trees of the hmon hin family is hovenia dulcis thunb. The species is relatively rare and is typically found in the stream-irrigated valleys of primary lower mountain evergreen forest located between 1,075 and 1,250 metres above sea level.

The hmon hin is a deciduous tree that sheds its leaves from late August to February. It flowers from December to May and bears fruit from August to January. According to Elliott, the species has so far been spotted in two sites in Thailand: the Doi Suthep-Pui National Park and Doi Khun Tan National Park. It also flourishes in Japan, the Himalayas, China and Korea.

''We recommend including it in tree planting programmes aimed at reforestation, because it will increase diversity. We also need to take steps to prevent it from becoming extinct,'' Elliott adds.

Unfortunately, the Forru team's research may soon come to an abrupt end. The current study is being sponsored by whisky importers Riche Monde (Bangkok) Company and the Guinness Plc Water of Life Company, and implemented with the support of the Doi Suthep-Pui National Park Headquarters. But there is little money left in the coffers and no new sponsor has yet been found.

''The whole concept of using a species of tree as the framework for reforestation needs further study,'' says Elliott. ''If we could complete the research to a satisfactory level, the benefits to forest land in Thailand would be tremendous. We are also adapting the concept for a pilot project on 200 rai of land in Chiang Mai's Ban Mae Sa Mai district.

''We have sufficient money to last us until the middle of 1998. The annual cost of the research project is around Bt800,000. But unfortunately our request to the national research funding agency, the Bio-diversity Research Training (BRT) for additional funds has been turned down, so it is unlikely that we will be able to continue our work.''

Just as it has affected every other aspect of life here, the economic crisis now threatens the Forru team's well-laid plans. Perhaps Elliott and his team should use the remainder of the grant to search for an environment in which money really does grow on trees.