Dr. Toni Klauschies

Foto von Dr. Toni Klauschies

 

Campus Botanischer Garten
University of Potsdam
Ecology and Ecosystem Modelling
Maulbeerallee 2, building 2, room 2.14
14476 Potsdam

Field of Interest

As a community ecologist, I am interested in the ecological processes that shape the temporal dynamics and spatial distribution of species in natural ecosystems. Decades of ecological research have shown that our mechanistic understanding of ecological processes and corresponding theory development substantially benefit from the integration and combination of empirical and theoretical work. In my daily research, I therefore combine experimental work and mathematical modelling. This includes conducting theory-driven population growth experiments and model-driven data analysis with a particular focus on pelagic ecosystems. My research relates to the following topics in ecology:

Studying temporal and spatial mechanisms that allow different species to coexist

I use multispecies predator-prey models to investigate the impact of coadaptation between species of the same or adjacent trophic levels on species coexistence in diverse communities in the light of modern coexistence theory (e.g. Klauschies et al. 2016, Ecology and Evolution). More recently, I have also become interested in studying the impact of spatial pattern formation on the maintenance of functional diversity and species coexistence in metacommunity models, which turned out to be a very intriguing topic on its own (e.g. Guill et al. 2021, Ecology Letters). Besides novel coexistence mechanisms through eco-evolutionary feedbacks and self-organized pattern formation, I am fascinated by classical coexistence mechanisms such as relative non-linearity and resource partitioning. For example, I theoretically investigate under which conditions relative non-linearity is more or less likely to promote consumer coexistence on a single fluctuating resource (e.g. Klauschies and Gaedke 2020, Theoretical Ecology).

Evaluating the impact of global change on natural communities

Anthropogenic changes of environmental conditions represent a major threat to natural ecosystems. Hence, I am also interested in the impact of anthropogenic stressors (e.g. salt pollution, toxin addition, nutrient enrichment, temperature enhancement) on the species population dynamics and the species composition of natural communities. For example, in a previous meta-analysis of different mesocosm experiments, I have shown that an increased temperature may lead to a shift in the phytoplankton community towards smaller algae as zooplankton feeding pressure increases (e.g. Klauschies et al. 2012, Marine Biology). In addition, the enrichment of ecosystems with salt can generally increase the mortality of planktonic organisms, although the strength of the negative effects may depend strongly on the quality of other biotic (Isanta-Navarro et al. 2021, STOTEN) and abiotic conditions (Klauschies and Isanta-Navarro 2022, STOTEN). Species may also respond to such altered environmental conditions through rapid evolution, which may prevent them from competitive exclusion. I therefore also study experimentally the adaptation of species to novel environmental changes (e.g. Isanta-Navarro et al. 2022, Proceedings B).

Testing and developing mathematical approaches to represent functional diversity in dynamical models 

When accounting for functional diversity in ecological models, we are usually facing a trade-off between complexity and tractability as well as generality. In trait-based aggregate models, for example, the shape of a trait distribution of a diverse community is usually approximated by a normal distribution. While this simple approach is convenient, as one only has to track the temporal dynamics of the mean and the variance of a trait distribution, my work aims (1) to identify the environmental conditions under which this assumption is (or is not) reliable, and (2) to improve this modelling approach by assuming a more flexible shape of a trait distribution as provided for example by the beta distribution (for details see Coutinho et al. 2016, Theoretical Ecology; Klauschies et al. 2018, Ecological Modelling; Acevedo-Trejos et al. 2022, Frontiers in Marine Science). In this context, I also consider the underlying assumptions and dynamical consequences of different modelling approaches to include phenotypic plasticity or genetic variation into dynamical models (e.g. Yamamichi et al. 2019, Ecology Letters)

Developing statistical approaches to analyze ecological data

Analyzing ecological data is part of my daily work. For example, I have examined the shape of observed trait distributions to test the frequently made assumption of the aggregate modelling approach that trait values are normally distributed (e.g. Gaedke and Klauschies 2017, Limnology & Oceanography: Methods). Thus, part of my data analysis serves to evaluate the suitability of modelling approaches, which often requires the development of novel statistical procedures. Furthermore, I investigate the extent to which eco-evolutionary processes can be inferred from time series of population sizes and traits. In this context, I use advanced methods in time series analysis such as Fourier and Wavelet Transformations or Moving Window approaches, which enable me to investigate and reveal time- and scale-dependent characteristics of eco-evolutionary processes (e.g. van Velzen et al. 2022, Ecological Monographs).

 

 

Foto von Dr. Toni Klauschies

 

Campus Botanischer Garten
University of Potsdam
Ecology and Ecosystem Modelling
Maulbeerallee 2, building 2, room 2.14
14476 Potsdam


Scientific career

since 2021              Research associate including laboratory co-leadership, Potsdam University

2016 - 2021             Post Doc Projekt DynaTrait, Potsdam University

2012 - 2016             PhD-student in the project “Understanding patterns of species covariation using a trait based approach with field data and models”, 
                                    supervised by Prof. Dr. Ursula Gaedke and funded by the German national science foundation (DFG), Potsdam University

 2012/2013             Jan. - Feb. 2012 and Aug.-Sep. 2013 visits at Yale University, USA, Department of Ecology and Evolutionary Biology, Prof. Dr. David
                                    Vasseur

2011                          Master in Education (Biology, Mathematics), Potsdam University

2008                          Bachelor in Education (Biology, Mathematics), Potsdam University


Publications

Acevedo-Trejos E. et al. (2022) Modelling approaches for capturing plankton diversity (MODIV), their societal applications and data needs. Frontiers in Marine Science

Isanta Navarro, J., T. Klauschies, A. Wacker and D. Martin-Creuzburg (2022) A sterol-mediated gleaner-opportunist trade-off underlies the evolution of grazer resistance to cyanobacteria. Proceedings of the Royal Society B.

van Velzen E, Gaedke U & Klauschies T.. 2022. “Quantifying the Capacity for Contemporary Trait Changes to Drive Intermittent Predator–Prey Cycles.” Ecological Monographs e1505.

Klauschies T., Isanta-Navarro J. 2022. The joint effects of salt and 6PPD contamination on a freshwater herbivore. Science of the Total Environment 829: 154675

Flöder S., J. Yong, T. Klauschies, U. Gaedke, T. Brinkhoff, T. Poprick & S. Moorthi (2021) Intraspecific Trait Variation Alters the Outcome of Competition in Freshwater Ciliates. Ecol. Evol.11: 10225–10243.

Guill C., Hülsemann J., Klauschies T. (2021).Self-organised pattern formation increases local diversity in metacommunities. Ecology Letters. DOI: 10.1111/ele.13880

Isanta-Navarro J., Arnott S.E., Klauschies T. &  Martin-Creuzburg D. (2021) Dietary lipid quality mediates salt tolerance of a freshwater keystone herbivore. Science of the Total Environment 769: 144657.

Klauschies, T. & U. Gaedke (2020) Nutrient retention by predators undermines predator coexistence on one prey. Theoret Ecol. 13, 183-208.

Ceulemans, R., Gaedke, U., Klauschies, T. & Guill, C. (2019). The effects of functional diversity on biomass production, variability, and resilience of ecosystem functions in a tritrophic system. Sci. Rep. 9: 7541 ONLINE

Koussoroplis AM., T. Klauschies , S. Pincebourde, D. Giron and A. Wacker (2019) A comment on "Variability in plant nutrients reduces insect herbivore Performance". Rethinking Ecology 4: 79-87, DOI:

Yamamichi M., T. Klauschies, B. E. Miner and E. van Velzen (2018) Modelling inducible defences in predator–prey interactions: assumptions and dynamical consequences of three distinct approaches. Ecology Letters, DOI: 10.1111/ele.13183.

Klauschies T., R.M. Coutinho and U. Gaedke (2018) A beta distribution-based moment closure enhances the reliability of traitbased aggregate models for natural populations and communities. Ecological Modelling, 381: 46-77. doi.org/10.1016/j.ecolmodel.2018.02.001.
Full text available at: https://authors.elsevier.com/a/1X4EZ15DJ~tXO9

Gaedke, U. and T. Klauschies (2017) Integrating Food-web and Trait-based Ecology to Investigate Biomass-Trait-Feedbacks. In: Adaptive Food Webs: Stability and Transitions of Real and Model Ecosystems. Cambridge University Press. Editors: John C. Moore, Peter C. de Ruiter, Kevin S. McCann, Volkmar Wolters.

Gaedke, U., B. E. Beisner, A. Binzer, A. Downing, C. Guill, T. Klauschies, J. J. Kuiper, F. Soudijn, and W. M. Mooij (2017) Importance of Trait-Related Flexibility for Food Web Dynamics and the Maintenance of Biodiversity. In: Adaptive Food Webs: Stability and Transitions of Real and Model Ecosystems. Cambridge University Press. Editors: John C. Moore, Peter C. de Ruiter, Kevin S. McCann, Volkmar Wolters.

Gaedke, U. and T. Klauschies (2017) Analyzing the shape of observed trait distributions enables a data-based moment closure of aggregate models. Limnology & Oceanography: Methods, DOI: 10.1002/lom3.10218. 

Klauschies, T., Vasseur D. A. and U. Gaedke (2016) Trait adaptation promotes species coexistence in diverse predator and prey communities. Ecology and Evolution, 6: 4141-4159 DOI: 10.1002/ece3.2172.

Coutinho, R., Klauschies T. and U. Gaedke (2016) Bimodal trait distributions with large variances question the reliability of trait-based aggregate models. Theoretical Ecology, 9: 389-408 DOI 10.1007/s12080-016-0297-9. 

Bauer B, M Vos, T Klauschies & U Gaedke (2014) Diversity, functional similarity and top-down control drive synchronization and the reliability of ecosystem function. Am. Nat. 183: 394 - 409.

Klauschies, T., B. Bauer, N. Aberle-Malzahn, U. Sommer & U. Gaedke (2012) Climate change effects on phytoplankton depend on cell size and food web structure. Mar. Biol. 159: 2455-2478.

Conference Contributions

Conference of the British Ecological Society (BES) 2017 in Ghent, Belgium: Enhancing the realism of trait-based aggregate models by considering important shape properties of natural trait distributions (Talk).

Meeting of the Priority Program DynaTrait (2017) in Hannover, Germany: The shape of natural trait distributions informs about fundamental processes structuring ecological communities (Talk).

Meeting of the Priority Program DynaTrait (2016) in Potsdam, Germany: Towards a general modelling framework: Embedding eco-evo-dynamics into multispecies models (Talk), Incorporating inter- and intraspecific trait variation into ecological models (Poster I). Theory meets data! Can trait-based aggregate models cope with real data? (Poster II).

Meeting of the Priority Program DynaTrait (2015) in Hannover, Germany: Bimodal trait distributions with large variances undermine predictions of aggregate models (Poster I), Fast and constrained intraspecific trait changes promote species coexistence (Poster II).

Meeting of the Priority Program DynaTrait (2014) in Machern, Germany: Interplay between trait variation, food web dynamics and maintenance of biodiversity (Talk)

Conference of the German Limnological Society (DGL) 2013 in Potsdam, Germany: Degree and speed of phenotypic plasticity influences species richness in multi-trophic communities (Talk)

Conference of the Ecological Society of America (ESA) 2013 in Minneapolis, USA: Phenotypic Plasticity Maintains Biodiversity (Talk)

Workshop of the Young Modellers in Ecology (YoMo) 2013 in Gülpe, Germany: Influences of intra- and interspecific trait variation on community dynamics and species coexistence. (Talk)

Workshop of the Young Modellers in Ecology (YoMo) 2012 in Craheim, Germany: Understanding patterns of species covariation using a trait based approach with field data and models. (Talk) 

Workshops

The importance of trait variation for the dynamics of ecological systems – Nefo netzwerk-forum zur Biodiversitätsforschung Deutschland