Subproject 1: Impacts of land use and climate change on terrestrial ecosystems and biodiversity

Project leaders:

• Anja Rammig and Andy Krause, Mona Reiss, Konstantin Gregor
• Wolfgang Weisser and Sebastian Meyer, Sven Rubanschi

Technical University Munich

Update December 2021

The LPJ-GUESS vegetation model can satisfactorily simulate the current state of Bavarian ecosystems. With today’s land use, ecosystems would continue to absorb carbon until mid-century (for a medium emissions scenario), after which saturation would occur. Large additional amounts of carbon could be stored through afforestation if agricultural land were freed up by higher yields or reduced (meat) consumption, particularly through afforestation of cropland. Alternatively, the freed-up land could be used to grow bioenergy crops such as miscanthus. However, this would only be advisable if the CO2 produced during combustion can be directly recaptured and stored underground in the long term; otherwise, afforestation is the better option. Changes in forest management (e.g., cessation of timber extraction, conversion to mixed forest) have a lower potential in the model. The results show that abandoned agricultural land has great potential for carbon storage. Reducing meat consumption and food waste are therefore effective climate change mitigation measures. Further model development is needed to reliably evaluate changes in forest management, particularly to more realistically simulate the effects of drought and disturbance events.

In the course of our research, the Vegetation Simulator Bavaria was created, an interactive web-based app that allows users to explore LPJ-GUESS simulations on their own. The user has the possibility to choose between different years, land use scenarios and variables and to display two different combinations at the same time.

 

By processing the biotope mapping, we were able to show that the area of biotopes is often very small. Often they are so small that several different biotopes occur under the same environmental conditions. As a result, several biotopes can be predicted for a given grid cell (Fig. see below). For most biotopes, climate variables are more important than soil variables. This indicates that future climate change will have a strong influence on future biotope distribution.
In addition, we showed that the potential distribution of many biotopes is greater than their current distribution. This is a result of overprinting by human land use such as agriculture. Our maps show which biotopes could occur in which regions.

Goal of the subproject

Global change is a threat to biodiversity, the functioning of ecosystems and the provision of ecosystem services in Bavaria.

To ensure ecosystem services – such as agricultural and forestry productivity, climate regulation, water quality, pollination and carbon storage in soil and biomass, and biodiversity – sustainable management strategies must be developed and operationalised. We investigate how climate change will influence land-use and land management. We evaluate the consequences for biological diversity and ecosystem services in Bavaria.

We apply the ecosystem model LPJ-GUESS to estimate climate-related changes in growth conditions. These results are used in subproject 4 to develop land-use change scenarios. From these scenarios, we derive estimates on biotope- and species-shifts or extinction are derived. For this, we make use of the unique dataset on Bavarian distribution of species and biotopes. In a “big data” approach, these are merged with the land use scenarios. Production functions are generated that relate land use and biodiversity to ecosystem services. Impact maps are generated that identify hotspots of biodiversity and show the danger of ecosystem services tipping over. Based on our results, possible pathways for a climate-adapted management is developed and discussed with different interest groups.