Scenario-modelling for the sustainable management of non-timber forest products in tropical ecosystems

Abstract

Ecosystems degradation, and consequently biodiversity loss, has severe impacts on people around the world. The Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) is one of the international initiatives that have emerged to inform policy makers and aid decisions to prevent further global biodiversity loss, focusing on the interdependence between natural systems and human culture. IPBES promotes the use of scenarios and modelling approaches as a fundamental tool to advance the understanding of the relationships between drivers of change, Nature’s Contributions to People (NCP), and social systems. Local-scale case studies with a system approach demonstrating how current knowledge can be used to inform decision-making are still scarce. Here, we present a comprehensive conceptual model and a series of four scenarios under different policies for shea tree species management, as a case-study of applying systems thinking and the NCP concept to a local-scale socio-ecological system. We first characterized the central processes, NCP, drivers and pressures affecting the shea tree system, to investigate the impacts of the multiple uses of the shea tree species on the system as a whole. We then described potential policy options, developed four scenarios, and evaluated them by a Bayesian Belief Network (BBN). We predicted qualitative outcomes of the proposed scenarios: Business-as-usual (BAU), “Conservation and fair trade”, “Agroforestry and fair trade” and “Industrial development”. We found that the scenarios focussing on conservation, fair trade and agroforestry, can improve the conservation status of shea trees, and enhance wellbeing in the local communities. In this case study, we demonstrate that the development of a comprehensive conceptual model at a local scale can be a useful exercise to identify opportunities for effective policy strategies and social innovation. The shea tree case study can provide an example for modelling non-timber forest products in other regions around the world that face similar drivers and pressures. Species for which this model could be adapted include Central and South American species such as the Brazilian nut (Bertholletia excelsa), cocoa (Theobroma cacao), andiroba (Carapa guianensis), açai (Euterpe oleracea) and the wax palm (Ceroxylon quindiuense). The model and workflow applied here may thus be used to understand similar socio-ecological systems with local and international economic value across the Neotropical region.

The use of machine learning in species threat and conservation analysis

“…land use class, soil texture class) sourced with spatially explicit data. Lastly, Bondé et al (2020) used a BBN on an arguably entirely theoretical level. They broadly identified three input variables (climate change, overexploitation, and land use change) influenced in turn by six input variables based on policy changes (e.g.…”

Increasing capacity to produce scenarios and models for biodiversity and ecosystem services

“…In particular, first, the key components were defined (Table 1) including the link between these key components, which was often represented visually by boxes with connecting arrows (Jackson et al, 2000). Key components varied greatly between case studies, such as water quality and quantity determining water health (Sarkar et al, 2020); forest cover change determined by urban expansion (Siqueira-Gay et al, 2020); and Shea tree cover and its harvest (Bondé et al, 2020). These key components provided the foundation on which to further build the complete conceptual model, as many influencing factors often play a role in determining changes in the key components.…”

“…These were commonly included in the case studies, such as for example in Siqueira-Gay et al (2020), where the socio-ecological system of forest cover change in the Amazon was investigated; or in Barbosa et al (2020) when evaluating pollination service changes in Brazil; or even in Estigarribia et al ( 2020) when analysing changes in biodiversity in the grasslands of South America. Additionally, indirect drivers commonly identified independently of the geographic location of the case study were population pressure, economic growth and international demand, governance, and policy changes, such as for example in the case of Dib et al (2020) for the Cantareira system in Brazil; or in Sarkar et al (2020) for the wetlands of Brazil and India; or in Lembi et al (2020) when analysing urban expansion in the Atlantic Forest; and in Bondé et al (2020) for the shea trees in West Africa.…”

The traditional uses of plant diversity in Gokwe South District, Zimbabwe: Timber & construction, ethnoveterinary medicine, firewood & charcoal, food, tools and handicraft, religious ceremonies & rituals & other uses

“…An estimated population of over 15 million in Sub-Saharan Africa have earned income through sale of forest products such as firewood, charcoal and handicraft production (Kaimowitz 2003). The demand especially for timber and firewood have placed a lot of pressure on important medicinal plants and the subsequent continual harvesting for timber or firewood could lead to their populations dwindling and ultimately affect global bioprospecting of important medicinal plants (Bondé et al 2020, Chomba et al 2013. Due to the versatility in the use of medicinal plants, they are prone to overharvesting pressure and overuse often leading to adverse effects such as dwindling of their population and in extreme cases, it could lead to important plant species becoming extinct.…”