In situ and Ex situ Conservation of Commercial Tropical Trees - ITTO

174D. alatus plantation area covers approximately 8 hectares, locatedalong the highway Nakorn Sawan – Kampaeng Phet. During the early stages,Cassia sp. seedlings were also planted to provide shade for the D. alatusseedlings. For preparation of D. alatus seedlings, instead of using polythenebags, bamboo containers were used and filled with a planting media of soil –sand – horse manure (1:1:1). The seeds were collected from plus trees naturallygrown in Kamphaeng Phet province using the method of ground collectionduring March through mid-April. Normally, seeds germinated within 11 – 15days and seedlings reached an average of 25 cm in height after being tended inthe nursery for 4 months. At this stage, the D. alatus seedlings totaled 2,937and they were ready to be planted out in the designated plantation area. In1966, an investigation of seedling survival rate was made, showing that only1,801 seedlings (61%) remained in the area. In 1972, the Forest ProtectionUnit undertook the first selective thinning operation No. KP. 3 (Tritreung) topromote better growth. A method of crown thinning was applied, in which upto 101 trees (7.27 m 3 ) were removed as were all Cassia trees (214 trees) inthe supplementary planting.In 1973, 13 D. alatus trees (2.37 m 3 ) were also removed. However,no research such as the establishment of permanent plots was made to studygrowth performance. This was initiated in 1986, when tree girths and treeheights of 1,155 D. alatus trees were measured. Based on calculations usingan average height of 12.4 m and an average GBH of 120 cm (average volumeper tree 1.1 m 3 ), the total wood volume was 1,282.6 m 3 at the age of 24 years.The GBHs of the smallest and largest trees were 32 and 200 cm, respectively.The D. alatus plantation activity at Tritreung Plantation Station was continueduntil 1967. However, since 1963, local people had expressed their displeasurewith the D. alatus plantation program, and this perhaps was the cause of thealmost annual fires in the plantation. Therefore, some empty areas where firedamagedtrees were removed were additionally planted with teak (Tectonagrandis). The data of plantation established in this area is presented in Table1. The preparation of teak cuttings by coppicing is easier compared with D.alatus. In conclusion, it appears that the oldest D. alatus plantation, establishedin 1962, exists today. This plantation is demarcated, undisturbed, and wellprotected.