Ecological Modelling by ‘Ecological Modelling'

On the basis of a statistical analysis of the papers published in Ecological Modelling from 1975 to 1996, it has been attempted to examine the development of the field of ecological modelling and systems ecology. It was found that while models of aquatic ecosystems and management issues were more in focus in the 1970s, terresterial ecosystems and ecological theory have gained attention during the 1990s. Interest in ecotoxicological models seems to have increased only slightly during the entire period. It is interesting that financial support for the area of ecological modelling and systems ecology is closely related to the number of publications, which can be seen from the number of papers published by various countries in the journal. Hopefully, this clear message can be used to show to politicians that these relationships are real.     

Modelling Ecological Presence–absence Data along an Environmental Gradient: Threshold Levels of the Environment

A methodology for estimating environmental thresholds of binary presence–absence data is presented where the level of the threshold is parameterised. Presence–absence data is fitted to three complementary different models: an independent null-model, a monotonically increasing or decreasing model, and an optimum model. The range of the three models is strictly between zero and one and the models are therefore well suited for modelling presence probabilities. The results of the three models may be combined by using Bayesian model selection methodologies. The proposed methodology is exemplified on observed binary presence–absence data of Bauera rubioides along an elevation gradient. Received: May 2005 / Revised: July 2005 An erratum to this article is available at.