Nature in Denmark continues to lack space, and nitrogen leaching from agricultural lands remains a major pressure on aquatic ecosystems. Since the first Danish Action Plan on the Aquatic Environment in 1987, successive policies have relied on setting land aside through voluntary agri-environmental schemes to reduce ni-trogen losses and improve environmental conditions. This approach continues under the Danish Green Tri-partite Agreement (2024), which assumes that land set aside will contribute simultaneously to improved water quality and biodiversity (Økonomiministeriet, 2024). However, after four decades of implementation, many water bodies remain in poor ecological condition and biodiversity gains have been limited.

This raises a fundamental question: why does land-use change not consistently translate into ecological improvements? Many factors influence the outcome of land-use change, including land set aside. The answer is likely to involve both biophysical conditions and the ways policies are implemented, interpreted and translated into management practices on the ground. In particular, temporal permanence and the spatial placement of the transition of the new types of land use are of vital importance to reach the targeted effects (UNECE 2021).

Policy implementation affects outcomes (Winter & Nielsen, 2013).  To understand how governance produces ecological results, we must understand how policy implementation shapes ecological outcomes in practice. Therefore, this PhD-project focuses on implementation, landowner motivation and how these factors influence the management of former agricultural land, and thereby the effects of the agro-environmental schemes. The project is structured around three analytical components, which will be examined using mixed methods combining quantitative geodata with qualitative interviews. The three analytical components are:

1. Land owner motivation and participation:

   • What motivates landowners to engage in land set-aside schemes, and how do policy incentives influence these decisions?

2. Governance and implementation processes

   • How does the regulatory framework and advisory system under the Green Tripartite Agreement shape decisions about where and how land is set aside?

3. Post-restoration management decisions
   • What factors and intensions influence management decisions on land set aside after restoration?

By assessing landowner motivation for setting land aside, the influence of the regulatory framework and advisory system and the intensions behind post-restoration management decisions, the project will hopefully provide knowledge about how land-use change can better contribute to improved aquatic ecosystems and biodiversity.The overarching aim is to learn how the implementation of agricultural policies, the surrounding advisory system and landowner motivation influence the ecological outcomes of setting agricultural land aside. Thereby, the project simultaneously contributes to the development of our Land-CRAFT theme IV research agenda, and the related Transform-DK.org Living Labs supporting the Transformation of the Danish Landscapes, as well as the PlantPerform New Nitrogen Regulation in Farmer and Advisor Decision Support projects.