Project:

Software for Simulation and Visualization of Ecological Competition in its Spatial Context

Funded by: MFG Baden-Württemberg

Project term: March to September 2008

brief description of the results [512 KB, en]

Abstract

Ecosystems are characterized by a wide variety of different interactions on different levels of organization. Competition plays a decisive role in most of these interactions and is thus to be regarded as a fundamental and ubiquitous ecological phenomenon.
Today this phenomenon deserves particular attention, due to all the ecological as well as economical problems caused by invasive species:

"In Germany for example, the economic losses caused by only 20 analyzed alien species, are estimated to reach 156 million Euros annually!" (Working Group NEOBIOTA, 2006)

"The approximately 50.000 non-indigenous species in the United States cause major environmental damage and losses totaling approximately 137 billion USD per year" (Pimental et al., 2000)

"Given the current scale of invasions and our lack of effective policies to prevent or control them, biotic invasions have joined the ranks of atmospheric and land-use change as major agents of human-driven global change." (Mack et al., 2000)

The competitive interaction between native and alien species lies at the very heart of these problems. A deeper understanding of its mechanisms is thus required.

To approach these problems not only a general understanding of the investigated systems is essential, but also a sound knowledge of each single case. A direct access by means of the methods of ecological field research is often strongly restricted. Typical problems arise from the complexity of natural systems which would require investigations on a sizable scale in terms of time and space. This might be a limit because of practical reasons, pressure of time or just money. Another drawback is that the species of interest are often critically endangered and experimental methods may pose an additional threat.
These difficulties can be avoided by the use of simulation models, - at least to a certain extent.
The method of modeling is not new to the field of ecology. But most established models are mathematical analytic functions. It is a weakness of this type of models, that they hardly take aspects of space into account. Individual based simulation models fill this gap as an appropriate tool to consider spatial processes.
Individual based models haven been used for about fifteen years in ecology. But this technique could and should be used more intensive and especially more efficiently. The actual state of affairs is pointed out by Grimm & Railsback (2005):

Individual Based Modeling "requires software expertise beyond the meager training ecologists now typically receive."

" ... most Individual Based Models have been built from scratch, using ad hoc assumptions not guided by general concepts."

It should be possible to deal with this situation by the enhancement of cooperations between computer scientist and ecologists. But such cooperations are still too rare.

This is where our project applies.

We will implement a spatially explicit, individual based simulation model, which will be based on the fundamental mechanisms of competition. An open structure will allow extensions.
We want to address two target groups:
For students we would like to provide an easily accessible education software. It shall allow them to gather an understanding of principle mechanisms of competition in their spatial context. This will be assisted especially by the visualization of the modeled processes.
For researchers we want to offer a tool, which enables them to investigate their special cases of competition, without having to implement a model from scratch. Our tool might serve as an easily extendable basis for them, because it will already contain the perseverative, fundamental mechanisms of competition. A framework will easily allow adding modules to extend the program and thus to adapt it to case studies.
At best any contributed extension will feed the software to become a constantly growing program-package.

Modeling 2.0

References

• V. Grimm & S. F. Railsback (2005):
  "Individual-Based Modelling and Ecology"; Princeton University Press: Princeton, NJ, 2005 ISBN 069109666X (pb)
  
• R. N. Mack, D. Simberloff, W. M. Lonsdale, H. Evans, M. Clout, F. A. Bazzaz (2000):
  "Biotic Invasions: Causes, Epidemology Global Consequenses and Control"; Ecologycal Applications 10(3), p. 689-710
  
• D. Pimental, L. Lach, R. Zuniga, D. Morrison (2000):
  "Environmental and Economic Costs of Nonindigenous Species in the United States"; BioScience 50-1, p. 53-65
  
• Working Group NEOBIOTA (2006):
  "Biological invasions need a strong legal framework at European level!" - Resolution adopted by the participants of the "4th European Conference on Biological Invasions" of the working group NEOBIOTA