ID do Resumo: 597

(canceled) Sustainability of Reduced-Impact Logging in the Eastern Amazon

Damage caused by reduced-impact logging (RIL) and post logging forest dynamics was assessed in 18 plots 1 ha each in a terra firme rain forest of Eastern Amazon (Brazil, Paragominas). Mean logging intensity was 6 trees/ha and the resulting commercial volume 21 m3 ha-1. On average, logging damage affected 16% of the original stand while skidtrails occupied 7% (661m2 ha-1) of forest soil area. Canopy openness doubled to a mean of 11%. Of the variables studied, “number of trees harvested or felled per plot” gave the best correlation to “proportion of damaged or destroyed trees”. Based on the dynamics variables (mortality and growth rate) recorded during 4 years after logging, we simulated the dynamics of potential crop trees. This simulation allow us to calculate a recovery level (RL) of the commercial stand that we defined as the proportion of potential crop trees reaching the minimum diameter cutting limit after a given period. Our results showed that within a 30 year felling cycle (i.e. the legal felling cycle duration in the Brazilian Amazon) and even under RIL systems, the present logging intensity occurring in the study area (6 trees ha-1) is not compatible with sustainable yield production on a long term basis. This study showed that in the Amazon, RIL alone is clearly not sufficient to achieve sustainable forest management. More sophisticated silvicultural systems must be urgently elaborated and implemented to ensure that the forest will still be sustainably managed on a long term basis. This issue is particularly important in the case of Brazil as a new law allowing the creation of 500,000 km2 of forest concessions by 2010 has been recently approved by the congress.

Sessão:  Carbono - Dinâmica florestal, perturbações naturais e regeneração. (B)

Tipo de Apresentação:  Oral