Predicting the provision of ecosystem services in coastal landscapes

Climate change threatens coastal areas of the North Sea and the Baltic Sea primarily through accelerated sea-level rise, increasing storm surges, and increasing winter rainwater discharge. Accelerating sea-level rise and changes in hydrological cycles are likely to affect coastal ecosystems and may restrict the efficiency of existing protective measures in the future. Here, we will present an inter- and transdisciplinary investigation of land management scenarios, applied to a North Sea and a Baltic Sea coastal region. These scenarios are combinations of three sea level rise assumptions, three regionalized climate change scenarios and four land management options. The land management options are (i) continuation of present land use, (ii) construction of polders to store excess winter rain water and prevent soil salinization in summer, (iii) construction of polders to grow reeds and provide peat production, and (iv) a multifunctional landscape option developed by stakeholders. We show the chain of models to quantify and evaluate the performance of multiple ecosystem functions and services in each scenario for the next 100 years in a spatially explicit way. The services comprise provision of forage, provision of biogas energy, mitigation of detrimental floods or droughts, reduction of greenhouse gas emissions, and preservation of rare plants and birds. Modelling includes process-based hydrological models and statistical species distributions models. We then model the provision of provisioning, regulatory and cultural ecosystem services based on the traits of the predicted species with yearly time steps until 2100 (Cebrián-Piqueras et al. 2017a, 2017b)
Our results show that a sustainable use of the coastal lowlands depends on the discharge of excess rainwater into the North Sea. In case of a continuation of the present land use combined with an assumed sea level rise of 80cm till 2100, natural discharge of rain water may not any more be possible around the year 2060. As a consequence, all excess rainwater may need to be pumped. Construction of polders or widening of ditches reduces the amount of water to be pumped. Loss of provisioning services such forage production is assessed against increases in the preservation of rare species and the reduction of pumping costs.