Subproject 2: Biodiversity tipping points in climate and land use change

Project leader:

Juliano Cabral and Anne Lewerentz, Jana Blechschmidt, Stefan Fallert

University of Birmingham, KIT & Julius-Maximilians-Universität Würzburg

Update December 2021

This subproject implements mechanistic models with detailed biological processes to predict the influence of climate and land use change on biodiversity in Bavaria.
For SP 2-1 the biodiversity of macrophytes and their distribution in Bavarian lakes was recorded. Overall, 71 immersed and 34 emersed macrophyte species can be found in the different big Bavarian Lakes at different depths (Lewerentz & Cabral, in press). The diversity of immersed macrophyte species forms a hump-shaped pattern along the depth gradient (Lewerentz et al 2021). These data are used to optimize the implemented eco-physiological model (Fig. 2a) as well as simulate future climate and land use scenarios with the optimized model. Based on the model and in collaboration with the institute Games Engineering of Würzburg University we developed a computer game for kids (premiered at Münchner Wissenschaftstage 2021) which teaches them about the ecosystem lake and the relevance of aquatic plants in a playful way (Lewerentz et al, in press).
For SP 2-2 we implemented a metabolic process-based model for range dynamics of vascular plant species (Fig. 1b) based on an existing model for terrestrial insects (Li 2020; Fallert 2021) and adapted for plants. We are currently defining the best method to optimize this model via the virtual ecologist approach to subsequently optimize the model using empirical data and finally simulate various scenarios.
SP 2-3 started recently and is currently extending the SP 2-2 model to include micro-evolutionary and interaction processes for insect species.
A synthesis subproject (SP 2-4) is still pending and will begin in spring 2022.

Fig. 1: Simplified scheme of the aquatic plant model MGM (a) and of terrestrial organisms metaRange (b). Pictured are the implemented mechanisms and influencing factors. Both models have been optimized for software complexity and runtime (s. Vedder et al. 2021 on model complexity).

Publications

Lewerentz, A., Hoffmann, M., & Cabral, J. S. (2021) Depth diversity gradients of macrophytes: Shape, drivers, and recent shifts. Ecology and Evolution, 11: 13830-13845. https://doi.org/10.1002/ece3.8089
Lewerentz, A. & Cabral, J. S. (in press) Wasserpflanzen in Bayern : Der Blick auf den See verrät nicht, was unter der Oberfläche passiert. In: Mitteilungen der Fränkischen Geographischen Gesellschaft Band 67: Herausforderungen des Klimawandels in Bayern. Erlangen 2021.
Lewerentz, A., Schantz, D., Gröh, J., Knote, A., von Mammen, S. & Cabral, J. S. (in press) bioDIVERsity: ein Computerspiel gegen das Imageproblem von Wasserpflanzen. In: Mitteilungen der Fränkischen Geographischen Gesellschaft Band 67: Herausforderungen des Klimawandels in Bayern. Erlangen 2021.
Vedder, D., Ankenbrand, M., Cabral, J. S. (2021) Dealing with software complexity in individual-based models. Methods in Ecology and Evolution, early view. https://doi.org/10.1111/2041-210X.13716

Finished Theses:

Bachelor Thesis: Lea Li. The extinction of species as a result of global warming: how increased metabolic rates upscale to species extinction dynamics. 2020, University of Würzburg.
Master Thesis: Stefan Fallert. Predicting the Future Distribution and Abundance of Species: a Mechanistic Range Model for Orthoptera in Bavaria. 2021, University of Würzburg.

News

Goal of the subproject

Climate change already has dramatic impacts on species and communities of species. So far, however, models have often only been used to investigate anthropogenic influences on individual species or on hypothetical communities of species. Therefore, it remains unexplored how climate change affects species communities in natural systems – both terrestrial and aquatic. The diversity and complexity of Bavarian landscapes is particularly suitable for researching how biodiversity reacts to climate and land use change.

In order to understand the potential effects of these interacting factors, the subproject investigates how aquatic and terrestrial species communities in Bavarian lakes and landscapes react to various changes in environmental factors. Spatially explicit niche and agent-based models for interacting plant and animal communities are being developed for this purpose. The simulated interactions between all relevant ecological processes result in the distribution and occurrence of plant and animal species within spatially structured communities. From the model results, biodiversity hotspots relevant to conservation are derived throughout Bavaria and displayed on maps.

Fig. 2: How are species communities changing in climate and land use change? To answer this questions, in BLIZ models are created based on measured data.

The subproject is divided in terrestrial and aquatic biodiversity: Makrophytes (SP2-1), terrestrial vascular plants (SP2-2) and insects (SP2-3). The final synthesis (TP2-4) has not yet started. The individual subprojects address the following research questions:

SP2-1 Makrophytes: 1) How are macrophytes currently distributed in Bavarian lakes and what is driving this distribution? 2) Can this distribution be replicated with an eco-physiological model? 3) How will climate and land use scenarios influence the future distribution of macrophytes?

SP2-2 Terrestrial vascular plants: 1) Which data are necessary for the reliable parameterization of a process-based model for range dynamics of plant species? 2) How do multiple species influence each other in their distribution? 3) How will chosen (red-listed) plants be affected by climate and land use change?

SP2-3 Insects: 1) Which processes must be inlcuded in a mechanistic model to describe the distribution of native insect species? 2) How can such a model best be parameterized? 3) How will species be affected by climate and land use change as well as migration measures?

SP2-4 Synthesis: 1) Summary of other subproject results; 2) Which conservation measures and biodiversity hotspots can be identified?