A natural neo tropical forest has been harvest in 1999 to evaluate the impact. The treatments were: commercial logging and reduce impact logging. It were found a positive relation between logging intensities and tree damage, and more tree damage more dead trees two years later.

All around the world tropical forest are being used mainly as a source of timber. In the same way they are decreasing in terms of biodiversity, ecological functions, and as sustainable resource. There are problems related to traditional forest management, harvesting impact, and forest restoration capacity. Since 1998, CIFOR and the Japanese Government have been developing a network focus on Rehabilitation of Degraded Tropical Forest Ecosystems. Eight projects are spare in tropical situations either in Asia, Africa and South America, covering plantations, degraded forest, and harvesting impact evaluation. During the phase I (1998-2000) experiments have been installed, and the first results are been published in several papers and books. The phase II, 2001-2003, emphasis is given to maintain the experiments and to encourage the publication and discussion of the project results. Particularly this project is related to evaluate harvesting impact in neotropical forest. In the Guarani Preservation Site (5343 has.) 21 plots of one hectare have been randomized in commercial logging, reduce impact logging and control plots treatments. Measures include forest structure, forest regeneration, harvesting stem damage, and soil impact like soil compaction and soil chemical characteristics. These measures are being repeated every year. The results after three year of harvesting allows to conclude that there are harvesting impact in soil compaction, forest structure, forest regeneration and forest damage. It seems like the neotropical forest do not have restoration capacity by itself, and even that the reduce impact logging produce less impact than the commercial one, the sustainability of this type of management is still and open question.

New knowledge, skills, or insights that participants will gain from session: 1) Sustainable forest management should consider the knowledge of the impact of forest harvesting. The use of traditional logging method in Neotropical forest management led to degraded unsustainable secondary forest. 2) It will be more important to manage the pressures that have led to degradation than to try and guide the course of re-vegetation. 3) This presentation shows the results after three years forest harvesting, and the fragile of the environment indicate that the timber production concept should change.