Thomas Evert, Valdivia Jheyson, Alcázar Caicedo Carolina, Quaedvlieg Julia, Wadt Lucia Helena O, Corvera Ronald
Bioversity International, Lima, Peru.
Universidad Nacional Amazonica de Madre de Dios, Puerto Maldonado, Peru.
PLoS One. 2017 Aug 24;12(8):e0183743. doi: 10.1371/journal.pone.0183743. eCollection 2017.
Understanding the factors that underlie the production of non-timber forest products (NTFPs), as well as regularly monitoring production levels, are key to allow sustainability assessments of NTFP extractive economies. Brazil nut (Bertholletia excelsa, Lecythidaceae) seed harvesting from natural forests is one of the cornerstone NTFP economies in Amazonia. In the Peruvian Amazon it is organized in a concession system. Drawing on seed production estimates of >135,000 individual Brazil nut trees from >400 concessions and ethno-ecological interviews with >80 concession holders, here we aimed to (i) assess the accuracy of seed production estimates by Brazil nut seed harvesters, and (ii) validate their traditional ecological knowledge (TEK) about the variables that influence Brazil nut production. We compared productivity estimates with actual field measurements carried out in the study area and found a positive correlation between them. Furthermore, we compared the relationships between seed production and a number of phenotypic, phytosanitary and environmental variables described in literature with those obtained for the seed production estimates and found high consistency between them, justifying the use of the dataset for validating TEK and innovative hypothesis testing. As expected, nearly all TEK on Brazil nut productivity was corroborated by our data. This is reassuring as Brazil nut concession holders, and NTFP harvesters at large, rely on their knowledge to guide the management of the trees upon which their extractive economies are based. Our findings suggest that productivity estimates of Brazil nut trees and possibly other NTFP-producing species could replace or complement actual measurements, which are very expensive and labour intensive, at least in areas where harvesters have a tradition of collecting NTFPs from the same trees over multiple years or decades. Productivity estimates might even be sourced from harvesters through registers on an annual basis, thus allowing a more cost-efficient and robust monitoring of productivity levels.
了解非木材森林产品（NTFPs）生产的潜在因素，并定期监测产量水平，是对NTFP采伐经济进行可持续性评估的关键。从天然森林中收获巴西坚果（Bertholletia excelsa，玉蕊科）种子是亚马逊地区NTFP经济的基石之一。在秘鲁亚马逊地区，它是通过特许权系统组织的。基于对400多个特许权区域内超过135,000棵巴西坚果树的种子产量估计，以及对80多位特许权持有人的民族生态访谈，我们旨在：（i）评估巴西坚果种子采集者对种子产量估计的准确性；（ii）验证他们关于影响巴西坚果产量的变量的传统生态知识（TEK）。我们将生产力估计值与在研究区域进行的实际实地测量结果进行了比较，发现两者之间存在正相关关系。此外，我们将文献中描述的种子产量与一些表型、植物检疫和环境变量之间的关系，与种子产量估计所获得的关系进行了比较，发现它们之间具有高度一致性，这证明了使用该数据集来验证TEK和进行创新性假设检验的合理性。正如预期的那样，我们的数据几乎证实了所有关于巴西坚果生产力的TEK。这令人放心，因为巴西坚果特许权持有人以及广大的NTFP采集者依靠他们的知识来指导对其采伐经济所依赖的树木的管理。我们的研究结果表明，巴西坚果树以及可能其他NTFP生产物种的生产力估计值可以替代或补充实际测量，实际测量成本非常高且劳动强度大，至少在采集者有多年或数十年从同一树木采集NTFPs传统的地区是这样。生产力估计值甚至可以每年通过登记从采集者那里获取，从而实现对生产力水平更具成本效益和稳健的监测。
