Implementing multiple forest management in Brazil nut-rich community forests: Effects of logging on natural regeneration and forest disturbance

Abstract

The encroachment of the logging frontier into Western Amazonia, where non-timber extraction has historically driven regional economies, provides an opportunity to explore the practice of multiple-use forest management. Families are now harvesting timber in their Brazil nut (Bertholletia excelsa)-rich community-titled forests, and we examined effects of formal and informal logging (with and without government-approved management plans, respectively) on forest disturbance and natural regeneration (individuals ⩽10cmdbh) of B. excelsa and 10 timber species in Northern Bolivia. B. excelsa regeneration densities 2–5years after timber harvests did not differ between unlogged or logged (formally nor informally) sites; densities were, however, greater in larger logging disturbances (i.e., log landings vs skid trails), corroborating our model in which canopy openness explained regeneration densities. Regeneration of the two most valuable timber species, Swietenia macrophylla and Amburana cearensis, rarely occurred, and only where conspecific trees were felled, implying that population recovery of selected species may need post-harvest silvicultural interventions. In contrast, two other high-value timber species (Cedrela odorata and Dipteryx odorata) responded favorably to disturbances. Contrary to our expectations and reported industrial-scale findings, formal logging resulted in a larger percentage, but still acceptable level, of disturbed area than informal logging (10.6%±0.65 SE vs 6.9%±1.26 SE; p=0.047).Our overall finding that Brazil nut regeneration was unaffected by low logging intensities suggests that combined Brazil nut and timber harvests are compatible under certain circumstances. Still, adhering to legal requirements has been challenging for individual landholders. Preparing legally-required management plans without assistance is difficult, and individual landholders seek to harvest timber over multiple years, which is discouraged by formal logging that indirectly entails one-time extraction of nearly all commercial stems from the approximately 200ha of forest landholders dedicate to timber production. Thus, reconciliation of legal requirements with community conditions is fundamental to long-term success of multiple-use forest management.