The Department of Madre de Dios in Peru, one of the most biodiverse regions on Earth, provides an ideal landscape in which to witness the impacts of anthropogenic disturbances on forest cover and structure. The local economy relies heavily on Brazil nut and timber, two important forest products that play critical roles in forest conservation and exploitation. Brazil nut concessionaires incorporate selective logging into their land use strategy (termed multiple-use forest management), in which they consider potential uses including timber, non-timber forest products (NTFPs), and other environmental services. Even so, few studies have demonstrated that timber and NTFP extraction can be sustainably managed in the same systems. Indeed, even when adhering to the legal channels, forest managers harvest timber in an opportunistic fashion with multiple entries into the same harvest zone. Many valuable hardwood species are now extremely rare in Brazil nut concessions within close proximity to the Interoceanic Highway, even though Brazil nut concessions are characterized by contiguous forest cover. This trend calls into question the integration of timber into traditional land management objectives, especially since most timber is harvested illegally.
Results/Conclusions
We investigated the influence of timber harvesting on changes in forest structure, woody species composition, available commercial volume, and commercial tree seedling abundance. Response variables were compared between three Brazil nut concessions (290-576 ha) using modified 0.5 ha Gentry plots. We discovered that logged sites were characterized by a lack of advanced regeneration, low commercial timber volume, reduced commercial taxonomic composition, and the removal of an already sparse canopy, suggesting that high grading is often the norm in this forest type. Results from this study will underscore the need for future monitoring of harvesting activities and residual stand dynamics as well as extreme caution in engaging in opportunistic logging practices. Enrichment planting, tending of natural regeneration, and incorporating silvicultural prescriptions into management plans could further protect the forest resource base from unsustainable harvesting practices.