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cooperation resource consumer systemExploring the evolution of cooperation with a simple resource-consumer system

 

With the Institutional & Behavioural Economics group, we developed a simple adaptive model with harvest behaviour as the main continuous trait describing the coupled dynamics of a renewable common pool resource and a group of human consumers. The balance between instantaneous harvest and potential future harvest determines the degree of cooperation among consumers. Consistent with Hardin's tragedy of the commons and numerous real examples, maximising the instantaneous harvest of the common pool resource leads to declining long-term yields and finally to a collapse of the resource-consumer system. By contrast, incorporating potential future returns into the consumer fitness function significantly enhance the degree of cooperation.


Related literature

G. Brandt & A. Merico (2013) Tipping points and user-resource system collapse in a simple model of evolutionary dynamics, Ecological Complexity, 13, 46-52.

G. Brandt, A. Merico, B. Vollan, & A. Schlüter (2012) Human adaptive behavior in common pool resource systems, PLoS ONE, 7(12), e52763.

adaptive plankton communityThe adaptive plankton community


Trait-based models can be constructed by incorporating principles derived from evolutionary biology and quantitative genetics to produce appropriate parameterisations of community behaviour. The use of traits to predict community composition can explain the organisation of ecological systems and predict their re-organisation in a changing environment. Trait-based models are able to describe the ecological community or the ecosystem as a whole entity making them also suitable for studying feedbacks between life and its environment on evolutionary time scales. The approach can be applied to social-ecological systems whose dynamics is described by the evolution of cooperation.

Organisms face trade-offs in their ability to allocate limited energy and resources to growth, reproduction and defence. A set of competing species can be specified in terms of their edibility (φ) and related ability for nutrient harvesting (α): α = 1 − κ − φ. The defensive low edibility trait in an algal clone comes at the cost of reduced fitness (reduced ability to compete for food).

The adaptive capacity of the system is mainly caused by a change in its components by species sorting processes (succession driven by interactions---resource competition in this case).

This trait-based modelling framework is based on general concepts and can therefore be applied to any ecological community of competing plankton species for which a trade-off between competitive ability and resistance to grazing can be appropriately defined.

Model plankton community trait based approachModelling a plankton community with a trait-based approach


Related literature:

E. Acevedo-Trejos, G. Brandt, J. Bruggeman & A. Merico (2015) Mechanisms shaping size structure and functional diversity of phytoplankton communities in the ocean, Scientific Reports, 5(8918), 1-8.

A. Merico, G. Brandt, S.L. Smith & M. Oliver (2014) Sustaining diversity in trait-based models of phytoplankton communities, Frontiers in Ecology and Evolution, 2(59), 1-8.

E. Acevedo-Trejos, G. Brandt, M. Steinacher & A. Merico (2014), A glimpse into the future composition of marine phytoplankton communities, Frontiers in Marine Science, 1(15), 1-12.

A. Merico, J. Bruggeman & K.W. Wirtz (2009) A trait-based approach for downscaling complexity in plankton ecosystem models, Ecological Modelling, 220, 3001-3010.

Korallenriff in Thailand

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The Ecology department analyses the importance of biodiversity for the structure of, and processes in, tropical coastal ecosystems on different organisational levels from individuals to communities and ecosystems.

We strive for a deeper understanding of interactions and interrelationships on different organisational levels. Increasing temperature in the ocean and decreasing oxygen (hypoxia or anoxia) or pH (acidification) are threats to the physiology of organisms (e.g. causing coral bleaching), and the effects are reaching to the community or even ecosystem level (e.g. causing reef degradation). Overfishing and eutrophication in their different facets impact first on the organism and community level, but may also change the ecosystem as such or drive genetic changes through selection processes. The knowledge of the relationship between biodiversity (changes) and ecosystem services under global change conditions is key in the work of the department.

We address these phenomena by looking into the physiological processes in single individuals of various species of ecosystem relevance to understand the reaction and threshold values of key species in the systems in relation to key parameters. We also look into processes like growth, reproduction and feeding of these key species to quantify the changes in the populations and their contribution to the systems’ services. 

The department contributes to the mission of ZMT by providing knowledge on the structure, the processes and the potential services of coastal ecosystems in the tropics, thus delivering key information for a sustainable management of coastal resources and ecosystem restoration.

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Indonesian carbon systemThe Indonesian carbon system

We investigate the effects of different emission and functioning scenarios of the "Indonesian carbon system" on the global carbon cycle. The Indonesian carbon system comprises various carbon reservoirs including the tropical rain forest, the peatlands, the seagrasses, the coral reefs and the neritic plankton. We assess and quantify the role of each of these components to different regional anthropogenic per- turbations with a box model of the global ocean to identify potential positive or negative feedbacks to the global carbon cycle.

The main focus of this study is to provide a quantitative understanding of the effects of peatland degradation on the carbon cycle on the regional and global scales. The results of our modelling work can be used to develop appropriate mitigation strategies.

Related literature:

J.F. Abrams, S. Hohn, T. Rixen, A. Baum & A. Merico (2016) The impact of Indonesian peatland degradation on downstream marine ecosystems and the global carbon cycle. Global Change Biology, 22(1), 325-337.


For more information check: SPICE and Topic 2

Biogeochemie und Geologie

Die Abteilung Biogeochemie und Geologie erforscht Veränderungen der abiotischen Umwelt und ihre Verbindung zur biotischen Welt über geologische Zeiträume.

Ökologie

In der Ökologie wird die Wichtigkeit der Biodiversität für die Struktur von und Prozessen in tropischen Küstenökosystemen untersucht. Dabei geht es  um verschiedenste organisatorische Ebenen - vom Individuum über die Gemeinschaften bis zum gesamten Ökosystems.

Sozialwissenschaften

Die Abteilung Sozialwissenschfaften erforscht die menschliche Dimension der Küstenökosysteme und der marinen sozio-ökologischen Systeme.

Theoretische Ökologie und Modellierung

Die Wissenschaftlerinnen und Wissenschaftler in der Abteilung Theoretische Ökologie und Modellierung untersuchen ökologische und sozio-ökologische Systeme und setzen dabei sowohl konzeptionelle und mathematische Modelle ein, als auch Computersimulationen und fortgeschrittene Datenanalyse.