‘Exclosures’ are not a new concept – but WLE research has refined their application so they successfully deliver for both fragile ecosystems and vulnerable communities.
The United Nations Convention to Combat Desertification (UNCCD) estimates that up to two thirds of Africa’s productive land is degraded – a challenge that is exacerbating poverty, weakening food and nutritional security and threatening biodiversity. ‘Exclosures’ are one promising solution. These are traditionally open access communal areas where wood cutting, grazing and other agricultural activities are forbidden or strictly limited to promote restoration and natural regeneration. Exclosures are not a new concept, but WLE research has helped to refine their application and embed these protected areas within wider landscape restoration efforts. An approach that also balances social, economic and environmental needs ensures that exclosures support livelihoods and, crucially, gain the backing of local communities.
WLE researchers have explored the optimal application of exclosures over several years. Research in the Afromontane forests of northern Ethiopia, for instance – which helped to successfully restore Olea europea subsp. cuspidate (wild olive), a highly valued source of firewood – revealed that extending restoration timeframes increased concentrations of soil carbon and nitrogen.
By adopting a systems perspective and understanding that exclosures are embedded within wider landscapes, WLE research has also explored the trade-offs that need to be quantified and factored into restoration planning. For instance, how plant growth can impact surface and sub-surface water fluxes and how the deeper and denser root systems of regenerating vegetation can reduce annual water yields through transpiration.
A further contribution has been the program’s work alongside communities, revealing promising approaches to build trust and strengthen collaboration. In Ethiopia, when a lack of alternative energy was causing the illegal harvesting of firewood within exclosures, researchers recommended widening access to renewable energy sources such as solar panels rather than establishing punitive rules. WLE has also identified how local communities can benefit economically from exclosures. The program has developed business models that allow local communities to generate additional income through sustainable economic activities, such as beekeeping and the cultivation of high-value plant species, without compromising long-term restoration objectives.
The insights gained from this research have contributed to important shifts in exclosure planning: a consideration of how exclosures affect and are affected by wider landscape interactions and an awareness that restoration efforts have to work in the interests of local communities and farmers – the best custodians of their environments.
WLE’s research has also contributed to the emergence of international principles and standards for the practice of ecological restoration. These provide a robust framework for restoration projects that help to achieve intended goals while addressing key challenges such as effective design and implementation, complex ecosystem dynamics and navigating trade-offs associated with land management priorities and decisions.
Although identifying revenue streams for local communities has helped overcome the challenge of balancing short-term economic losses with longer-term economic and environmental gains, this approach has not been applied everywhere.
Predicting the outcomes of exclosure restoration efforts is also difficult, given that outcomes are dependent on complex mechanisms with many uncertainties and risks. However, WLE’s development of a stochastic evaluation framework, which integrates available data and expert opinion to simulate outcomes, has demonstrated some potential.
Furthermore, applying cost-benefit analyses, often based on precise models of systems functions, can be inadequate when data are scarce or of low quality; evidence gaps and long-term planning horizons make it difficult to secure the investments needed to scale up restoration efforts; and efforts to value restoration outcomes complicate the task of assigning monetary value to ecosystem services with low and often unknown market value.
Despite the challenges, there is now growing global momentum behind restoration efforts. The UN Decade on Ecosystem Restoration, launched in 2021, is an ambitious and broad-based global movement which intends to build political support for restoration and coordinate thousands of on-the-ground initiatives. The African Landscapes Restoration Initiative (AFR 100), a country-led pan-African effort to restore 100 million hectares of degraded and deforested landscapes by 2030, is also underway. WLE’s research on exclosures and restoration will continue to inform these and other initiatives – providing lessons and insights to ensure efforts are evidence-based, inclusive and more precisely targeted.