COPPICE GROWTH OF SOME TROPICAL TREE SPECIES IN MINDANAO ISLAND, THE PHILIPPINES

A study on coppicing capability of some tropical trees, including Leucaena leucocephala, Gmelina arborea, Tectona grandis and Pileostigma malabaricum var. acidum, was undertaken with particular emphasis placed on their initial sprout growth and the factors affecting the production of sprouts in Mindanao Island, the Philippines. The growth of sprouts of these species was so outstanding: it was 5-10 m in height and 4-6 cm in diameter in the first year. This could lead to shorten the rotation period to a greater degree compared with temperate trees, provided that the site for coppicing is adequately selected. A stump size was recognized to have a positive effect on the initial growth of sprouts. This suggests that larger trees may be cut to produce more and larger sprouts. A reciprocal relation existed between the sprout growth and the sprout density regarding the stump of G. arborea and T. grandis. On the basis of this relationship, a threshold density of sprouts was estimated in order to identify appropriate criteria in conducting a sprout thinning on a given stump. Concerning the cutting system, a clear-cutting or a heavy crown thinning would be suitable for producing larger and healthier sprouts to reproduce the stands.