Propagating native trees to restore degraded forest ecosystems in northern Thailand

ABSTRACT: Producing a wide range of native forest tree species to restore forest ecosystems for biodiversity conservation is beset with nursery-scheduling problems. Different species produce seeds at different times of the year and they have different growth rates, yet all seedlings must grow to a plantable size at the same time of the year. A research programme was begun in 1997, to formulate production schedules for various forest tree species that are indigenous to northern Thailand, and to determine optimum propagation methods. Basic data were collected on species performance in the nursery, from seed collection to planting out. In this short report, we present detailed results for four tree species that are suitable for forest restoration plantings (Bischofia javanica, Castanopsis tribuloides, Ficus semicordata and Dalbergia rimosa) and a summary production schedule for 35 species. Of these, 12, 22 and 1 species respectively reached plantable sizes by the 1st, 2nd and 3rd planting season after seed collection. The amount of nursery time required, to grow seedlings to optimal planting size, ranged from 6 to 25 months.