Feedback analysis in reserve management: studying local myths using qualitative models

A qualitative modelling approach is used to highlight potential feedback me chanisms and secondary effects of management actions on a number of key spe cies in a large Argentine wetland. The development of this qualitative mode l, in this case a loop model, was a first step in the creation of an overal l management and monitoring programme for this important wetland. The use o f loop models is a possible strategy in environmental management and monito ring programmes of large complex natural reserves, in which little quantita tive data is available. Based upon observed ecological information, several loop trophic models were constructed and appropriate links made to reflect actual trophic relationships between trophic variables. The potential seco ndary effects of a hunting ban on caiman in a large shallow lagoon were exa mined. Indirect secondary effects were found to produce unforeseen negative impacts on other predator species (piscivorous birds, piranha) and species important to the abiotic environment (large bottom dwelling fish). As ther e are limited quantitative data, field investigations and the development o f other types of models an necessary to examine in detail the quantitative variations on the populations in question. The results of this model were f ound useful to indicate where further study and quantitative data gathering might be best focused. (C) 2000 Elsevier Science B.V. All rights reserved.