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28th Systems Science Colloquium

Winter semester 2021/22

The colloquium takes place on Wednesdays from 16:15 to 17:45.

This semester, there is a mixture of onsite (Präsenz) and online colloquia.

• Onsite colloquia take place in room 35/E16 (biology building, Barbarastraße 11). There are two options of participation: (a) onsite or (b) online via a live stream. In the latter case, please register in StudIP for Systemwissenschaftliches Kolloquium.
• Online colloquia take place via a videoconference in BigBlueButton. The link will be announced. There are two options of participation: (a) online via the link of (b) onsite in room 35/E16 via a projection of the videoconference on a screen.

Please see the program below for which colloquia will be held on-site or online.

PDF file of the program for download

Program

01 December 2021, onsite

Prof. Dr. Björn Waske, Osnabrück University, Institute of Computer Science, Remote Sensing and Digital Image Analysis:
Multisensor remote sensing and machine learning for monitoring spatial-temporal land use patterns

08 December 2021, onsite

Prof. Dr. Volker Grimm, Helmholtz Centre for Environmental Research, Department of Ecological Modelling:
Modeling honeybees under stress with BEEHAVE: Lessons for theory, practice and systems science

05 January 2022, online

Prof. Dr. Vrushali A. Bokil, Oregon State University (USA), Department of Mathematics:
Optimal control of plant disease epidemics
Joint Mathematics and Systems Science Colloquium

12 January 2022, online

Prof. Dr. Ralf Schäfer, University of Koblenz-Landau, Institute for Environmental Sciences:
The role of multiple stressors including toxicants in the loss of freshwater biodiversity

19 January 2022, online

Prof. Dr. Paul van den Brink, Wageningen University and Research (The Netherlands), Environmental Risk Assessment:
Ecological risk assessment of chemicals: From book-keeping to chemical stress ecology

26 January 2022, online

Prof. Dr. María Alejandra Vélez, University of Los Andes (Colombia), Faculty of Economics:
Have behavioral sciences delivered on their promise to influence environmental policy and conservation practice?

02 February 2022, online

Dr. Ulrike Schlägel, University of Potsdam, Institute of Biochemistry and Biology:
Movement-mediated community assembly and coexistence

Abstracts of presentations

01 December 2021
Prof. Dr. Björn Waske, Osnabrück University, Institute of Computer Science, Remote Sensing and Digital Image Analysis

Multisensor remote sensing and machine learning for monitoring spatial-temporal land use patterns
The transformation of natural ecosystems, e.g. due to agriculture, deforestation and urbanization is one of the major drivers of global environmental change. Earth Observation (EO) systems provide spatially distributed and temporally frequent information on land use and land cover and became a valuable and powerful tool to monitor the Earth. However, the increased availability of different, often complementary EO data, the availability of massive open data archives and increasing performance requirements demand increasingly improving strategies for data analysis. Various developments and applications will be introduced to underline the potential of multisensor remote sensing imagery and machine learning for monitoring spatial-temporal land use patterns.

08 December 2021
Prof. Dr. Volker Grimm, Helmholtz Centre for Environmental Research, Leipzig

Modelling honey bees under stress with BEEHAVE: lessons for theory and practice
What drives the decline and collapse of honey bee colonies? Several individual stressors are discussed, such as pesticides, diseases, reduced land use diversity or beeking practices, but there is growing consensus that multiple stressors are responsible. Since it is impossible to study all combinations of stressors in controlled experiments, models are needed to integrate and focus empirical research. BEEHAVE (www.beehave-model.net) is the first model to integrate spatio-temporal forage supply in the landscape, foraging, energy and pollen budget, hive demography, diseases and beekeeping practices. I will present BEEHAVE and its purpose, its underlying rationale and past and future applications. I will also discuss how models for decision support should be designed and presented and why theory is necessary also for applications.

05 January 2022
Prof. Dr. Vrushali A. Bokil, Oregon State University (USA), Department of Mathematics

Optimal control of plant disease epidemics
Mathematical models of plant–virus and plant–vector–virus models have provided insight into effective methods for reduction of disease incidence and for increase in plant productivity. The distribution and use of pathogen-free planting material (“clean seeds”) is a promising method to control plant diseases in developing countries. We address the question of minimizing disease prevalence in plants through the optimal usage of clean seeds. We consider the simplest possible Susceptible - Infected model for plant disease transmission together with a simple economic criterion to be maximized. The static optimization problem shows a diversity of possible outcomes depending on economical and epidemiological parameters.  The dynamical results are comparable to the static ones. In particular, the condition on the critical subsidy rate that makes clean seed usage economically viable is unchanged from the static optimization case. We discuss how these results may apply to the control of maize lethal necrosis in East-Africa. Finally, we also discuss other examples of the use of mathematical modeling and optimal control theory in controlling plant disease epidemics. This research is based on joint work with Linda Allen at Texas Tech University in Lubbock, Texas, USA; Pierre Bernhard at Université Côte d’Azur, Inria, INRAE, CNRS, Sorbonne Université, Biocore in France; Brady Bowen, PhD student at Oregon State University; Frederic Hamelin at IGEPP, INRAE, Institut Agro, Univ Rennes in Rennes, France; Mike Jeger at Centre for Environmental Policy, Imperial College in London, UK; and  Suzanne Lenhart at the University of Tennessee in Knoxville, TN, USA.

References: 

1. V. A. Bokil, L. J. S. Allen, M. J. Jeger and S. Lenhart, Optimal Control of a Vectored Plant Disease Model for a Crop with Continuous Replanting, Pages 325-353, Volume 13, Journal of Biological Dynamics, 2019.
2. F. M. Hamelin, B. Bowen, P. Bernhard and V. A. Bokil, Optimal Control of Plant Disease Epidemics with Clean Seed Usage, Bull Math Biol 83, 46 (2021). https://doi.org/10.1007/s11538-021-00872-w

12 January 2022
Prof. Dr. Ralf Schäfer, University of Koblenz-Landau, Institute for Environmental Sciences

The role of multiple stressors including toxicants in the loss of freshwater biodiversity
The loss of biodiversity is widely debated and freshwater biodiversity is considered at particular risk. Several stressors, occurring in mixtures and acting at different spatial scales, impact freshwater biota. I briefly discuss the evidence for a general decline in freshwater insect biodiversity. Subsequently, based on recent results and publications, I present an overview of the occurrence of chemicals in streams at the regional, national and larger scale. Moreover, I provide insights on the relevance of toxicants in comparison to other stressors and demonstrate the relevance of considering the spatial dimension when assessing the risks to (meta-)populations. I end with a discussion of how to improve our capacity to predict chemical effects on communities, where I present a novel framework integrating different theoretical ecotoxicological perspectives.

19 January 2022
Prof. Dr. Paul van den Brink, Wageningen University and Research (The Netherlands), Environmental Risk Assessment

Ecological risk assessment of chemicals: From book-keeping to chemical stress ecology
The presentation will show how the effects of chemicals and other stressors like climate change propagate though the levels of biological organisation. As most of the assessment of chemical effects is based on the results of single species tests, this is needed to address the protection goals set by regulatory bodies. Examples for an effect assessment of chemicals on individual levels will be given both based on experimental as modelling approaches, including toxicokinetic-toxicodynamic modelling. Population models and semi-field experiments using microcosms and mesocosms will be presented as tools to address the population and ecosystem level, thereby including indirect effects due to ecosystem interactions and recovery of affected populations. The talk will end with a reflection on how the effects of multiple stressors can be assessed, both experimentally as using ecological models.

26 January 2022
Prof. Dr. María Alejandra Vélez, University of Los Andes (Colombia), Faculty of Economics

Have behavioral sciences delivered on their promise to influence environmental policy and conservation practice?
After four decades of refining our understanding of decision-making processes, a form of consensus has developed around the crucial role that behavioral science can play in changing non-cooperative decisions and promoting pro-environmental behaviors. However, has behavioral science delivered on its promise to influence environmental policy and conservation practice? In this presentation, I discuss key lessons coming from recent empirical research on the dual process theory of thinking and the presence of cognitive biases, social norms and intrinsic motivations. Recent studies focus on providing feedback, manipulating framing, using green nudges, or activating social norms on urban contexts, mainly energy and water. Interventions are needed in the context of common pool resources in the global south. Lastly, I discuss the great potential for scaling-up programs and interventions, as well as of remaining challenges for research and practice.

02 February 2022
Dr. Ulrike Schlägel, University of Potsdam, Institute of Biochemistry and Biology

Movement-mediated community assembly and coexistence
As the field of movement ecology is maturing, it’s time to put the study of animal movement into the context of ecological questions. One big question in ecology is that of the maintenance of species coexistence: why do species with similar ecological needs and habits persist (long term) next to each other without competitive exclusion? Coexistence theory provides a solid framework for studying this question and an array of mechanisms that can explain species coexistence. However, the models underlying the theory operate at the population level and require us to know, e.g., how species growth rates depend on the environment. For animals, this is mediated by behaviour that occurs at the individual level, and this is where insights on animal space-use strategies can help us. In this talk, I will present some of my work towards a better understanding of how animals’ mobility may facilitate coexistence within guilds of similar species. This will include results from a simple computer simulation model, statistical developments for detecting animal interactions from movement data, and a case study on a small-rodents community.

Archive: Previous Colloquia