Habitat suitability modelling in auto-ecology analysis of Azolla filiculoides (Lam.) azollaceae in Selkeh wildlife refuge (Iran)

Invasive aquatic species are more and more becoming a worldwide problem. Especially exotic species are affecting biodiversity. They may substantially change communities and ecosystems. Azolla filiculoides (Lam.) is such an exotic species in Selkeh Wildlife Refuge (northern Iran). It is rapidly spreading and has a serious impact on the area’s aquatic communities. The purpose of the present study was to make use of field data and modelling techniques to analyse the ecology of A. filiculoides in Selkeh wetland. Classification tree (CT) methods were used for habitat suitability modelling of A. filiculoides. Various structural habitat and physico-chemical variables were used as inputs whereas and 3 classes (low, medium and high) of A. filiculoides cover served as output for the models. Of the 33 variables presented to the model, validity of 9 variables was confirmed for the prediction of habitat requirements of A. filiculoides. A logical link was found between A. filiculoides distribution and structural habitat variables such as depth, air temperature, humidity and light intensity of wetland. Besides, nitrate and orthophosphate concentrations were found to be two main nutrients for prediction. CTs allow the selection of the most important variables and thus provid critical information to support definition and implementation of an A. filiculoides management programme in Anzali wetland