Nguyen Van Diep
INTRODUCTION
Thinning of Manglietia glauca plantations is urgent at present because many production organizations have large areas of Manglietia glauca plantation, but no thinning technique, so that plantations have the original density as at planting. Trees are in lacking space, natural pruning is strong, crowns are small and plantations show a tendency towards a decreasing increment which can result in low productivity, bad quality and prolonged rotation.
Our study aims at finding techniques for thinning Manglietia glauca plantations to make them into big-sized wood forests having high productivity, good quality and short rotation.
RESEARCH CONTENTS AND REMARKS
1. SELECTIVE THINNING
According to data collected in Manglietia glauca plantation established in 1964, average height in 1971 was 11.9m and breast-height diameter was 12.5cm.
If we followed random thinning i.e. cut 1/2 of trees in stand, average diameter of stand was 12.4-12.5 cm. If we used selective cutting, diameter of remaining trees was 13.9cm, thus after thinning, we increased the average diameter of stand from 12.5 to 13.9cm, so the exceeding percentage was 15%.
By random thinning, cutting 1/2 of trees means eliminating 1/2 of total volume, however, by using selective thinning, cutting 1/2 of tree numbers could decrease only 40% of total volume and there was 60% of volume left.
Through selection, the remainder were fast growing trees having a strong increment and they can rapidly reach a large size.
Latest news
- Project: Study on integrated management of insect pests and diseases on Docynia indica in northern Vietnam
- Project: Study on integrated pest management of major leaf insect pests and stem borer beetles in Acacia hybrid, A. mangium and A. auriculiformis in Vietnam
- Project: Research and develop an integrated management program for control of cinnamon pests in some main cinnamon growing areas (Northern mountainous region and Quang Nam province)
- Project: Pilot plantation and completion of planting techniques of technologically advanced germplasm of Acacia auriculiformis (AA42, AA53, AA56, AA92, AA95) for sawlog in the southeast and south central.
- Project "Research on selection of varieties and intensive afforestation techniques of Prunus arborea (Blume) Kalkman for providing lager timber in the Northeast and Northwest regions, Vietnam"
Oldest news
- increment rules of manglietia glauca planted stands for forest management work (1974-1977)
- preliminary study on some technical measures for intensive cultivation of e.exserta plantations in midland area at dailai, vinhphu (1971 - 1975)
- investigation of soils for planting e.exserta and e. tereticornis, and influence of e.exserta mono-species plantations on soil fertility in bare hill areas (1972 - 1974)
- some research results on measures to control termites in eucalyptus plantation (1973 - 1975)
- study on prevention and control of weak-yellow disease of p.merkusii seedlings, based on rules of symbiosis with fungus (1971 - 1976)
