O manejo do óleo-resina de Copaifera spp. realizado pelas etnias Arara (Karo) e Gavião (Ikolen) na Terra Indígena Igarapé Lourdes, Rondônia

Abstract

This study dealt with the evaluation of management for oil-resin production of three species of Copaifera. The evaluated management techniques have been practiced for many years in the indigenous reservation Igarapé Lourdes in Rondônia by the ethnic groups Arara and Gavião. Several surveys were carried out to determine: species identification, number of potentially productive individuals, and physicochemical oil-resin characterization in addition to the abundance and productions of different Copaifera species. The abundance of potentially productive Copaifera multijuga (copaíba mari-mari) averaged 3.6 individuals per hectare, and C. piresii (copaíba angelim-vermelho) averaged 1.4 per hectare. Another Copaifera, which is popularly known as copaíba angelim-branco was also included in this study. In terms of physicochemical characteristics of the oil-resin, the species of Copaifera presented the following differences: C. multijuga is more fluid, bright, less acid and saponifiable than Copaifera sp., which is dark, thick, acid and saponificated; C. piresii presented intermediate characteristics. The oil-resin extraction techniques adopted during the past eight years for economical purposes have shown that all managed trees were correctly perforated using manual drills. However, holes of 33 individuals were not properly sealed; therefore, the invasion by termites was facilitated. In those holes properly sealed the presence of termites was moderate. The number of productive trees was quite similar in both oil-resin extraction occasions, i.e., there is no difference between the first and subsequent extractions; maybe the good practices for extraction could be the main reason for this fact. The production rates were significantly different between C. multijuga and C. piresii; for trees in the first extraction C. piresii performed better than C. multijuga, and in the second extraction occasion, the performance was just inverted. This result indicates that C. piresii trees can accumulate more oil-resin in their interior, which could be an artifact due to their diameters that are larger than those of C. multijuga. In the second or subsequent extraction occasion C. multijuga presented good performance in refilling the stem with oil-resin, which helps to maintain a uniform production of the species. On the other hand, individuals of C.piresii have presented lower production rates over time. The best performance in terms of oil-resin production was obtained in larger trees whose diameters varied from 63 to 72.9 cm, which means that diameter size is highly and positively correlated with oil-resin production.