Given their substantial societal benefits, such as supporting economic activities and providing better livelihoods in rural areas, ecosystem services should gain higher importance in water-food-energy nexus debates. Yet, not all values from ecosystems are quantifiable, data is often not adequate and methods of measuring these values are not sound. This situation challenges researchers and water managers to improve research tools and give adequate attention to ecosystem services by implementing interdisciplinary approaches and integrated management of ecosystems and their services.

The water-energy-food nexus concept is criticized as not yet fit for deeply integrated and contested governance agendas. One problem is how to achieve equitable risk governance and management where there is low consensus on priorities, poor inclusion and coordination of risk assessment procedures, and a weak emphasis placed on cross-scale and sectoral interactions over time. Participatory system dynamics modeling processes and analyses are promising approaches for such challenges but are currently underutilized in nexus research and policy. This paper shares our experience implementing one such analysis in the Mekong river basin, a paradigmatic example for international nexus research. Our transdisciplinary research design combined participatory causal loop diagramming processes, scenario modeling, and a new resilience analysis method to identify and test anticipated water-energy-food risks in Kratie and Stung Treng provinces in northeastern Cambodia. Our process generated new understanding of potential cross-sectoral and cross-level risks from major hydropower development in the region. The results showed expected trade-offs between national level infrastructure programs and local level food security, but also some new insights into the effects local population increases may have on local food production and consumption even before hydropower developments are built. The analysis shows the benefit of evaluating risks in the nexus at different system levels and over time because of how system dynamics and inflection points are taken into account. Additionally, our case illustrates the contribution participatory system-thinking processes can make to risk assessment procedures for complex systems transitions. We originally anticipated that any new capacity reported by partners and participants would come from our modeling results produced at the end of the process. However, participants in the modeling procedures also found the experience powerful the information sharing, rapid risk assessment, and personal learning it enabled. A lesson from our experience reinforces a message from the transdisciplinary research field that has not yet been absorbed into the nexus research and policy field wholeheartedly: we do not have to wait for perfect data and incontestable results before making a positive contribution to anticipating and responding to risks that emerge from nexus relations if we apply participatory and systems-thinking informed approaches.

Forest ecosystem services are critical for maintaining ecological balance and supporting human well-being from different perspectives. However, rapid land use changes driven by agricultural expansion, urbanization, and industrial activities have significantly altered forest ecosystems, degrading the services they provide. We here conduct an ecosystem service assessment through biophysical and economic estimates for a multipurpose Andean water sub-basin in western Colombia. We compare a business as usual (BAU) with a forest nature-based solution (NbS) scenario focused on forest landscape restoration. The research employed participatory methods for the NbS selection and economic valuation techniques to evaluate water flow regulation, water provisioning, water purification, and food provisioning services. Results show that the NbS scenario yielded a net positive economic impact across most evaluated ecosystem services, with notable trade-offs. Specifically, the NbS scenario increased water retention by 2.9% compared to BAU. Water flow regulation demonstrated the most substantial economic benefit, increasing by EUR 11.39 million/year in the NbS scenario. On the other hand, the food provisioning service presented a reduction of EUR 3.2 million/year in the NbS scenario. These findings highlight the potential of forest-based NbS to address the Water–Energy–Food–Ecosystem (WEFE) nexus challenges. The study’s outcomes provide valuable insights for policymakers and practitioners, supporting the development of Payment for Ecosystem Services schemes and integrating ecosystem service valuation into land use planning and decision-making processes.