I'm currently involved in the following projects
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Polar TimeDuring evolution, a wide range of organisms from cyanobacteria to humans have adapted to the day-night cycle, caused by the earth’s rotational movements, by developing an endogenous timing system – a circadian clock – that allows synchronization of metabolism, physiology and behaviour with the environment and that also may modulate seasonal responses. In marine organisms in general, little is known about the principles of endogenous clocks and how these clocks interact with environmental cycles. Marine ecosystems are currently experiencing rapid anthropogenic climatic changes. In particular, polar and sub-polar latitudes comprising the fastest warming regions on the planet with profound impacts on the marine environment. The overall aim of the Helmholtz Virtual Institute (HVI) PolarTime is to create a center of excellence of international standing to study the principles, interactions and evolution of endogenous biological rhythms and clocks in polar pelagic organisms. Emphasis will be placed on invertebrate key species who’s biology is so pervasive as to dictate ecosystem functioning. The Southern ocean key species Antarctic krill, Euphausia superba, will act as model organism to study the endogenous clock machinery and its effect on daily and seasonal life-cycle functions. The results will act as solid basis to study and understand the mechanisms of temporal synchronization of other key polar pelagic organisms. Embedded modelling studies will enable us to understand and predict how the ongoing environmental changes will impact the clock machinery and consequently the life cycle of key species and hence the whole polar marine ecosystem. In this project I develop and analyse an ontogenetic model of krill development |
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Competition for resourcesThe principles of species coexistence have mostly been studied in uniform environments. However, natural environments are usually characterized by gradients and non-homogeneous distribution of resources. To date, we are largely unaware what conditions can provide maximum of the species richness and stability of the community, optimal stoichiometry and efficient use of resources. The classical approach based on differential equation is a very convenient tool for the analysis of uniform systems. However, its straight forward application for competition in spatial systems encounters many mathematical difficulties. In order to investigate competition in spatially extended systems we have developed a graphical approach based on the analysis of invasion thresholds, - curves in space of species parameters which separate species that can survive in given conditions, from the species that cannot. Applying this analysis we have already discovered new fundamental results, which show a principle difference between competition in uniform and spatial system. See publications for further information. Currently we are developing this approach further. Motivated students are welcome to proceed this research.
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Role of connectivity for maintenance of diversity in experimental plankton communitiesAquatic diversity across temporal and special scales (AQUASCALE)Duration: 01.12.2013 - 30.11.2016
PI: Robert Ptacnik Funding: FWF |