Research on Lowland Forest.

The Framework Tree Species Method for Lowland Deciduous Forest in Northern Thailand

FORRU has successfully carried out forest restoration, using the framework species method, in upland forests at Ban Mae Sa Mai. One of FORRU's current objectives is to determine the best techniques for the restoration of degraded lowland areas in northern Thailand, formerly covered by deciduous forests. In these areas, natural forest recovery it severely constrained by 3 major factors: 1) high fire risk, ii) presence of domestic cattle and iii) severely degraded soils. A summary of research on lowland species restoration is presented here.

This work is supported by Thailand's Biodiversity Research and Training Program (BRT). Between 2006 and 2008, this project was sponsored under the project BRT_R 348006 “Establishing test plots for adaptation of the framework species method of forest restoration for biodiversity recovery in deciduous forest ecosystems”. For more details of this project, the final report (March 2008) to BRT is available at the following link: 
Lowland Framework Species: Final Report 2008. The current project, “Propagation and performance trials of framework tree species for restoration of deciduous forest ecosystems” will continue until 2010. The end of first year report can be seen at the following link: First Year Report.

With support from Thailand's Biodiversity Research and Training Program (BRT), FORRU has been working to optimise theframework species method to restore biodiversity in degraded deciduous forests at lowland sites. This project commenced at two sites, the Phrae Campus ofMae Jo University
and Mae Ow Watershed Development Project in Lamphun Province. The site at Mae Ow was abandoned due to forest fire and cattle damage in the hot season of 2007, and experiments were tranferred to Huay Teung Tao reservoir in Chiang Mai province, where experimentation continues.
Left: FORRU Research Nursery Staff with trees planted at Huay Teung Tao in 1997

Lowland deciduous forest tree species are different from those that have been proved to be successful framework species at higher elevations. The first and most critical step in adapting the framework species methods to any new forest type is tree species selection.

Therefore, we used existing data to select candidate framework species most suited to the harsh conditions of the lowland sites. This project involves two tree nurseries, which are now growing a total of 64 tree species for testing as framework tree species. Suitable seed germination treatments are being tested and production schedules are being researched and developed to ensure that trees are ready for planting in the early rainy season.
 Right: Khun Thonglaw and a Ficus callosa 3 months after planting in 2008.

Before tree planting, surveys were carried out to determine the initial condition of the vegetation, bird communities and soil conditions, so biodiversity levels can be compared between before and after planting. Ten rai of experimental plots were established at both Mae Jo and Mae Ow in July 2006, including planting 15 candidate framework species. An additional four rai were planted at both Mae Jo and Huay Teung Tao in June 2007, and four rai at Huay Teung Tao in June 2008, adding up to a total of 22 rai of experimental plots planted.
Above: Ajarn Somboon from CMU surveying birds at Huay Teung Tao.

Germination trials were carried out to determine the most effective techniques to propagate potential framework tree species for deciduous forests. Silvicultural treatments tested included filling the planting hole with compost and various fertiliser application regimes. Monitoring results at the end of t
he first rainy season indicated that good survival and growth rates had been achieved. Initial indications are that more intensive treatments (compost in the planting hole and high rates of fertilizer application) are likely to achieve the best results.

In 2009, an additional 4 rai of plots were planted at Huay Teung Tao. In addition to testing new candidate framework species, these plots are testing the effectiveness of different weeding regimes in the lowland context.

By working closely with the Royal Thai Army, local NGO’s and schools, the plots at HTT are now beginning to fulfill their secondary role as educational facilities for forest restoration. The site was used a venue for the field trip of the workshop “The Future of Forest Restoration Research in Indochina” held in March 12-14th 2008. About 50 international delegates were able to observe the high growth rates. 
Right: Khun Somkit stands with a 3 month old Erythrina stricta planted in 2008.

In addition, CMU and the Royal Thai Army have worked on a proposal to manage this area as a bird corridor, adjoining Doi Suthep Pui National Park. Plans are underway to create more bird habitats in this area, increase forest cover and create educational trails and signs for visiting students. The bird sanctuary proposal is copied in the appendix. Furthermore, about 40 children from Prem International Centre joined in the planting event as part of their environment group’s extracurricular activities. Several interns (university students) at FORRU-CMU have joined in the maintenance and monitoring activities at the plots. The demonstration plots at MJU Phrae Campus have also been used for class work for about 200 students, for forest restoration lessons and field labs work. The plots were visited by teachers from Vietnam and local villagers also received training in tree propagation methods at the nursery.

The progress of the planted trees has been monitored at regular intervals since planting. The forest fire at Mae Ow provided the opportunity to study the fire resistance of the tree species.

Devising a framework species system to restore deciduous forests in northern Thailand has become a far more challenging task than expected. In evergreen forest, framework species were easy to identify, and we had identified a functional range of species and achieve impressive demo plots within 3-4 years after starting nursery and field work. This was probably because i) there are more species to choose from in evergreen forest; ii) conditions for tree growth are much better ab
ove 1,000 m elevation than in the lowlands and iii) human disturbance, especially cattle and fire, was less intense. In deciduous forest, the main problem has been fire and cattle destroying the planted trees before completion of field trials, despite considerable expenditure on fire break cutting and employment of local people for fire prevention and suppression. Having shifted the field trial plot system to Huay Teung Tao has allowed the project to progress with less difficulties with cattle and fire so FORRU will continue to expand the field trial plots in this region. 

Left: Nursery staff Khun Thongyod and Khun Somkit inspect Cassia bakeriana, three months after planting in 2008.