Forest and landscape restoration (FLR) is a promising strategy for improving water, energy and food securities (WEF-Nexus). We advocate that 'forest security' should form a fourth, foundational dimension of a novel water, energy, food and forest security nexus (WEFF-Nexus) framework. Key principles of this new framework support an integrated role of forests in sustainable development, and engagement of local communities in nature-based solutions, particularly in the Global South.We believe that this new approach can help to accelerate the pace and magnitude of changes needed for achieving the United Nations Sustainable Development Goals.
Main textSafeguarding biodiversity and promoting a sustainable and equitable sharing of the planet's natural resources is one of humanity's major challenges 1 . Forests are irreplaceable for maintaining biodiversity and provide crucial direct and indirect benefits to people 2 . Unfortunately, high rates of deforestation and land degradation are transforming landscapes to the extent that they require environmental protection to slow these processes and restoration interventions to support flows of ecosystem services 3 . Severely degraded landscapes have low conservation value and reduced capacity to support human well-being now or in the future 4 . Additionally, three-quarters of poor people worldwide live in rural areas 5 . Managing these altered landscapes to maintain agricultural productivity as well as diverse ecosystem services that support sustainable livelihoods often presents a "wicked problem" -i.e. trade-offs are common 6 .Forest and landscape restoration (FLR) has emerged as a socio-ecological approach to expand restoration objectives and restore landscape characteristics such as productivity, resilience, and sustainability 7 . However, FLR demands complex multidisciplinary approaches based on reliable, coherent conceptual frameworks 8 . Understanding, foreseeing, and minimizing trade-offs is crucial to achieve so-called 'win-win' outcomes for the environment and societies 7 . One possible solution lies in building a holistic framework that recognizes the role of forests as paramount for ecosystem functionality and human well-being. This framework for guiding policy interventions would not eliminate trade-offs but should, ideally, help to recognize, anticipate, and minimize them 9 .Much forest restoration research focuses on targeting priority areas for increasing forest cover based on biophysical and socioeconomic features of landscapes. For instance, Banks-Leite and colleagues 10 used biodiversity conservation thresholds to map and prioritize areas for strategically restoring the Brazilian Atlantic Forest and proposed that re-purposing only 6.5% of the existing agricultural subsidy for that region would support cost-effective restoration on private lands. Another comprehensive study 7 calculated a restoration opportunity score for all tropical