Ökologische Modelle verstehen – Studien zu Osmia rufa

Abstract

Ulbrich, K.: Understanding ecological models – studies with Osmia rufa. - Hercynia N.F. 38 (2005): 125 – 135.Web-based education software was developed which deals with an ecological simulation model addressing the dramatic situation of wild bee species in Middle Europe. The Red Mason bee Osmia rufa (also known as O. bicornis) is taken as a representative for wild bees. Field studies were carried out from 1997 to 1999 in the Botanical Garden of the University Halle. They indicated a high variability in the numbers, sizes and sex ratios of offspring within individual nests. Contrarily, the variability at the population level was low. Describing how population dynamics emerge from individuals’ behaviour, the model focuses on the maternal investment in relation to habitat parameters. The process of modelling is explained beginning from the derivation of hypotheses and assumptions up to the implementation into a C++ program and generating of model results. A specific user interface favours the input of model parameters and scenarios to simulate short-term and long-term dynamics as well as the extinction probability of virtual Osmia-rufa populations. The impact of selected parameters can be studied by varying them at run-time. Numerous interactive components and self-checks are included to enhance the learning process.