Habitat suitability models for control of the invasive fern species Azolla filiculoides in the Anzali wetland (Iran)

Invasive alien species are a major threat to ecosystems. They can change habitats and alter ecosystem functioning and related services, crowd out or replace native species, and damage human activities. The control of exotic species such as A. filiculoides is globally considered as a critical task in the new invaded areas. Habitat suitability models can help to determine the biotic or abiotic factors which affect the presence/absence, and density and abundance of such exotic organisms. These models are potentially applied for decision support in aquatic ecosystem management. In this doctoral thesis, classification trees model was used for analysing the habitat preferences of A. filiculoides in Selkeh wildlife refuges located in the Anzali wetland, northern Iran. The models illustrated that both climatic and water quality variables are important for the growth and development of the fern in the wetland. For management, conservation and restoration purposes, more attention should be paid to the water quality characteristics of the wetland since the climatic variables are unmanageable. To achieve this, appropriate integrated environmental management programs are needed to manage pollution, biodiversity conservation and sustainable development. The main issues are to identify the point and non-point sources of pollution entering the wetland and to apply proper environmental management programs and appropriate wastewater treatment plans to control pollution entering to rivers that ultimately come to the wetland