How will land degradation neutrality change future land system patterns? A scenario simulation study

Highlights: • We simulate land system changes for achieving LDN in Turkey. • Land degradation was mostly caused by annual cropland intensification. • Counterbalancing degradation was mostly achieved through reforestation. • Our results highlight the need for alternative ways to avoid degradation. • Land system models provide insights in LDN implementation challenges and trade-offs. Land degradation is a major global issue and achieving a land degradation-neutral world is one of the Sustainable Development Goals. However, striving for land degradation neutrality (LDN) is challenged by increasing claims on land resources and could result in major land use conflicts. The aim of this study is to demonstrate how LDN can be implemented in land system modelling and how achieving LDN alongside sufficient supplies of food, timber and shelter could affect future land system patterns, using the Republic of Turkey as a case study. We developed a LDN scenario with full implementation of the guidelines and a business-as-usual scenario without pursuing LDN, and compared the resulting differences in land system changes. Additionally, the influence of different elements of the LDN framework on the land use projections was tested. Our results show that although it is possible to achieve LDN in the context of increasing demands for resources and housing, it might require a considerable re-organization of the land systems. Intensification of annual cropland systems was the main driver of new land degradation, which was in the LDN scenario primarily counterbalanced by large areas of afforestation, while other land improvement options only played a minor role. To achieve a no-net-loss, about 20% of Turkey's territory was afforested in our scenario, mainly claiming extensively used annual cropland (∼70%) and grassland (∼30%). All individual LDN principles had a substantial impact on the final land system patterns meaning that the final outcome is not the result of just one of the principles, it is affected by all. Our findings suggest that pursuing LDN under growing demands for land-based products could stimulate a land sparing approach which might have trade-offs with other sustainability dimensions. This highlights the need for local support and new solutions for rural areas, thereby avoiding poverty, migration and illegal use of restoration areas.