PARAMETER-ESTIMATION OF ECOLOGICAL MODELS

Determining the parameter values of ecological models poses special problems caused by nonlinear model structure, parameter correlations and data scarcity. All these aspects justify a numerical approach, which is pursued here through an efficient numerical optimization procedure based on the flexible polyhedron search. This paper describes the algorithm and its application to the estimation of some well-known microbial kinetics encountered in many applications in ecology and biotechnology. After assessing the main features of the algorithm, an estimate of the parameter covariance matrix is derived and related to system sensitivity. In the last part of the paper extensive numerical tests are discussed to assess the algorithm performance in dealing with noisy measurements. The numerical results show that the method is computationally robust and performs well even with heavily noise-corrupted data. The algorithm was implemented using Borland's Turbo BASIC and the source code is available for research purposes.