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Báo cáo lâm nghiệp: "Sustainable cutting cycle and yields in a lowland mixed dipterocarp forest of Borneo"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài: Sustainable cutting cycle and yields in a lowland mixed dipterocarp forest of Borneo. | Ann. For. Sci. 60 2003 803-814 INRA EDP Sciences 2004 DOI 10.1051 forest 2003075 803 Original article Sustainable cutting cycle and yields in a lowland mixed dipterocarp forest of Borneo Plinio SISTa Nicolas PICARDb Sylvie Gourlet-Fleuryc a Convênio Cirad-Forêt-EMBRAPA Amazonia Oriental Travessa Eneas Pinheiro Belem PA 66095-100 Brazil b Cirad-Forêt BP 1813 Bamako Mali c Cirad-Forêt TA 10D 34398 Montpellier Cedex 5 France Received 19 February 2002 accepted 19 December 2002 Abstract - Based on a 6 year monitoring of the dynamics of a mixed dipterocarp forest in East Borneo 1990-1996 we built a matrix model to predict the sustainable cutting cycle in relation with the extraction and damage rates. Plots were ordered according to three main groups of damage and logging intensity. The first group G1 gathered slightly damaged plots with a remaining basal area 80 of the original mean logging intensity 6 trees ha-1 . Plots belonging to G2 had a remaining basal area varying between 70 and 79 of the original one mean logging intensity 8 trees ha-1 . Finally G3 gathers highly damaged plots with a remaining basal area 70 of the original one and a high logging intensity mean 14 trees ha-1 . The mean sustainable cutting cycles predicted in the three groups were significantly different and equal 27 41 and 89 years in G1 G2 and G3 respectively. However the respective mean annual extracted volumes were similar 1.6 1.8 and 1.4 m1 3 ha-1 year-1 respectively in G1 G2 and G3. The model suggests that a 40 year cycle extracting 8 trees ha-1 60 m3 ha-1 and an annual volume of 1.5 m3 ha-1 year-1 is the best option to preserve ecological integrity of the forest to ensure yield sustainability and according to existing cost analysis economic profitability. This result is also consistent with other studies which already demonstrated that logging damage reduction using RIL techniques could be only significant with a moderate felling intensity not exceeding 8 trees ha-1. This felling intensity .