A Participatory System Dynamic Modelling approach to manage Biodiversity-Climate-Society Nexus. The case study of handicraft production in the Amazon Forest
Authors: Santoro Stefania , Francesconi Wendy , Mello Denyse , Pagano Alessandro , Giordano Raffaele 
Published: March 2024

The 'Biodiversity-Climate-Society' (BCS) Nexus deals with the interconnections among climate, ecological, and social systems and is in principle similar to the well-known Water Energy Food Environment (WEFE) Nexus. Basically, they both focus on the interdependencies among sectors and key resources, and aim at understanding how sectors (and agents operating in each sector) interact each other. The idea behind the BCS Nexus reflects the need for a deeper understanding of the challenges that also involving WEFE, due to the existence of physical heterogeneity, uncertainty, and non-linearity relationships among environmental and social systems. The BCS Nexus involves embedding water-related challenges in a broader spectrum in which managing the trade-offs related to the use of the resource among the climate aspect, biodiversity alteration and ecosystem degradation, social and economic and dynamics.
Within this framework, the present work specifically contributes to the scientific debate related to the BCS Nexus, proposing an approach for the transition from Nexus thinking (i.e. understanding the complexity) to Nexus doing (i.e. managing the complexity) in the analysis of complex value chains. The research activities are being performed within the European BIOTRAILS project (HE, GA 101082008).
System Dynamic Modeling (SDM) approaches, specifically based on the use of Causal Loop Diagrams (CLDs), have been used to support a better understanding of the BCS Nexus. CLDs are used for a more holistic and accurate representation of the interconnections among sectors and to facilitate the visualization of inter-sectoral relationships. The value added of the proposed approach is that CLDs are built in a participatory manner, thus involving stakeholders through different activities in model building and validation. Face-to-face interviews, focus groups and stakeholder workshops are used for the purpose.
CLDs are then analyzed through a structural and a descriptive analysis. The former is based on the use of centrality metrics, from graph theory, that help identify key variables in the system. The latter is based on the analysis of feedback loops. They jointly allow to formulate hypotheses on the potential dynamic evolution of the Nexus challenges based on their position within the system and to identify the elements that could generate change.
The methodology has been developed for all the BIOTRAILS case studies, but the present work deals with the case study of the activity of handicrafts production in the Amazonian state of Rondonia (Brazil). The area is undergoing severe ecosystem degradation due to the overexploitation of water and soil, logging activities, and infrastructure development, which have repercussions on biodiversity and the hydrogeological control of forests with effects on the local climate. In addition, unauthorized activities also compromise the livability of indigenous communities.
Participatory SDM shows relevant potential in supporting the integration of multiple Nexus components into a single, unified model. It offers insights into the identification of potential interventions to support resource management by policy and non-policy makers, and improving the society-science-policy interface. Furthermore, the participatory construction of the model serves as a powerful communication tool to engage stakeholders, foster dialogue, explore alternative futures, make informed decisions, and plan management choices that promote sustainable management of BCS Nexus.