This page lists a few more details about me, in addition to my official homepage.



  • 1983 - 1988: study of biology at Rostock University and Technische Universität Dresden
  • Diploma degree: Statistical data analysis and Monte Carlo simulation with the lake model SALMO
  • 1988 - 1996: scientist and “computer person” at the Institute of Hydrobiology
  • 1996: PhD about possibilities of phytoplankton prediction with different models approaches
  • Since 1996: scientist at the Institute of Hydrobiology: teaching, research projects, computer network administrator


My list of publications can be found in any of the following dictionaries:


  • Ecological Statistics and Systems Analysis (in German, Master Hydrobiology, 10cp)
  • Applied Statistics (in English, Master Hydroscience and Engineering, 5cp)
  • Participation in several limnological lab and field courses about ecology of lakes and reservoirs for Bachelor Hydrosciences, Bachelor Biology, Master Hydrobiology and Master Hydroscience and Engineering.

Research Interests

  • Ecological modelling for systems understanding and water quality management.

  • Specific scientific and practical questions:
    • Eutrophication control, especially role of phosphorus and nitrogen,
    • Evolution and spread of antibiotic resistances,
    • Ecological stability of benthic communities,
  • Development of open source tools for the efficient implementation of ecological models.

Our modelling technology depends on the question. We use differential equations and individual-based simulations but also statistical models or neural networks. The size of the models can be different as well, from very simple process models up to models at the ecosystem level (e.g. coupled lake model SALMO).

Research Projects

  • NITROLIMIT 2 - Nitrogen limitation in freshwaters - Is nitrogen reduction ecologically meaningful and economically feasible?
    • Part: Lake Modelling - Direct and indirect effects of N-load and N-turnover on the structur and function of lake ecosystems.
  • Currently several collaborations.

Finished Projects

  • Development of an hydrophysical-ecological coupled reservoir model system (Joint Project GETAS)
  • Integrated management of multi-purpose drinking water reservoirs (Joint Project IntegTA)
  • International Water Alliance Saxony IWAS, Regional Projekt Ukraine
  • Ecological role of the secondary metabolite “Microcystin”
  • Model-aided analysis of climate change impacts on planktonic food webs (part of the DFG Priority Program AQUASHIFT)
  • Role of reservoirs within catchment areas e.g. River Spree (Germany) and Western Bug River (Ukraine)
  • see also: research page of the limnology workgroup.


  • Member of the German Limnological Society (DGL), the International Society of Limnology (SIL) and of the R Foundation for Statistical Computing,
  • Working group member of the German Drinking Water Reservoir Management Group (ATT),
  • Associate Editor of the “Journal of Statistical Software” (JSS), Reviewer for several international limnological and ecological journals.


Most downloads below use the R software and you may ask why…

Several years we were working with different systems and languages like Fortran, Basic, Pascal, Delphi, JAVA, C/C++, Spreadsheets, Simulation Dynamics tools etc. Now we do most things in R and some time critical parts in C/C++ or Fortran. Why?

R is more efficient for us: easy programming, fast enough, packages for “almost everything”, flexible graphics, supports writing up research. Important was also, that the R community uses scientific publications for communication and getting scientific credit. We still use other software, but only with R we feel it worth to make our tools publicly available.

R Packages

deSolve (Soetaert, Petzoldt, Setzer): the main workhorse for initial value problems of differential equations in R.

FME (Soetaert, Petzoldt): tools for sensitivity analysis, model fitting and Markov chain Monte Carlo (MCMC)

marelac (Soetaert, Petzoldt, Meysman): tools for aquatic sciences; chemical and physical constants, physical properties of seawater and dissolved substances, calculation tools

simecol (Petzoldt): implements an “object model of models”, applicable to ODE/PDEs, IBM/ABMs and cellular automata

qualV (Jachner, Boogaart, Petzoldt): model validation criteria, especially for models with time delay

proto (Grothendieck and Petzoldt, now maintained by Hadley Wickham): implements lightweight prototype-based (i.e. classless) object orientation

cardidates (Rolinski, Sachse, Petzoldt): peak-fitting and determination of “cardinal dates” in environmental time series

growthrates (Petzoldt): fit population growth models to experimental data

Resources for students


Course pages

  • List of modules given by our institute
  • My course pages in the OPAL system.