Broadleaved hedgerows as Nature-Based solution for restoring the resilience of Atlantic pine forests

One of the greatest challenges in building more resilient forestry lies in figuring out how to initiate changes in forest practices to better protect biodiversity and ecosystems, while operating within an already highly optimized and profit-oriented system. Although the scientific community is often very effective in diagnosing the weaknesses of current agricultural and forestry models and proposing innovative solutions, the transition from a poorly resilient, yet widely accepted state to amore adaptive but hypothetical one often faces significant on-the-ground realities. These include adapting the wood-production oriented management, overcoming legislative barriers or confronting the different expectations of local stakeholders.

The Landes of Gascony Forest is one of the largest man-made forests in Europe, located in southwestern France. The million hectares of maritime pine plantations and almost two centuries of its existence have shaped a deeply rooted forestry culture among local populations. This is associated with a highly intensive and optimized forest management, that rose diverse concerns under growing threats to the forest ecosystem and socio-economic resilience. Even the most severe disturbances in the past, such as the storms of 1999 and 2009 which damaged 60% of the area, or the large-scale forest fires of 2022 were not enough to bring about a change towards more resilient forest management practices, due to the lack of consolidated alternatives. The recent detection of the pine wood nematode is the latest dramatic opportunity to rethink our forest management system and landscape restoration strategies.

Selecting a demonstration area and engaging stakeholders through a living laboratory approach, as promoted by the SUPERB and TRANSFORMIT projects, has proven highly effective in creating a positive atmosphere for collaboration and mutual learning to aid in the development and adoption of new practices. Local stakeholders with diverse profiles (public, private, practitioners, NGOs, policy makers...) regularly become involved in the living lab to share experiences, guide research and experimentation, learn from the field trials and disseminate results.

Moreover, adopting a nature-based solution such as the establishment of diversified broadleaved hedgerows along maritime pine plantations offer both a real positive impact on biodiversity and resilience at the stand and landscape scale, while not compromising productive pine management. Scientific studies undertaken to understand the effect of diversified hedgerows on various species communities (insect, soil fauna, flora), on tree health issues, and on the vulnerability of the landscape to windstorms and fire have provided robust evidence to help convince stakeholders of the need to adapt their management practices.

Several years of hindsight for testing the establishment of new hedgerows in the pine forest has enabled refinement of the technical details, and has helped to anticipate plant supply and legislative constraints. The restoration efforts have resulted in the establishment of 50 km of newly planted hedgerows, partly funded through the engagement of a private charity to overcome economic barriers.