Impact of oleoresin harvesting on the reproductive phenology of Copaifera pubiflora Benth. (Leguminosae) in a precipitation gradient in northern brazilian Amazon

Abstract

Few studies have addressed the sustainability of harvesting of secondary compounds from non-timber forest products (NTFP). Most of them suggest that reproductive aspects can be compromised due to competition for resource allocation. These impacts may depend on the harvest history and may be more pronounced in environments with lower resource availability. This study assessed the impact of different oleoresin harvesting intervals on the reproductive phenology of Copaifera pubiflora Benth. (Leguminosae) in two tree populations with different harvesting time spans (mid- x short-term) and resource constraints in Roraima, northern Brazilian Amazon. We evaluated the impact of different intervals of consecutive oleoresin harvest compared to a control group without harvesting. Tree populations are found in forests with different precipitation ranges: (i) an ecotonal forest at the savanna-tropical rainforest boundary (intervals: 18 months, six months; mid-term; less constrained forest), and (ii) a gallery forest within the savanna ecosystem (12 months, six months; short-term; greater constrained forest). Data on the number of trees in different phenophases and fruit abortion were obtained fortnightly for two years and ten months. The occurrence, duration, and activity (number of trees) of the phenophases were examined through circular analyses. Our results indicate that oleoresin harvest did not affect the timing and duration of reproductive events, and the interval between successive collections should be considered when designing more sustainable management practices. Long-term studies should be conducted to assess whether observed patterns are maintained and to determine the optimal oleoresin harvest interval so trees can allocate resources for defense without competing with other functions.