The influence of horizontal and vertical biodiversity on the effects of stressors on aquatic ecosystems

Summary

The biodiversity of ecosystems can be characterized by horizontal (diversity within trophic levels ) and vertical diversity (number of trophic levels). The aim of my thesis provides is to study the relationship between diversity and stability, and to study environmental risk assessment (ERA) of chemicals in aquatic ecosystems, by dividing diversity into horizontal and vertical diversity. To accomplish the objectives above, I combined experiments, long term monitoring datasets and modelling approaches. These approaches together bring us to the conclusions 1) that horizontal and vertical diversity have contrasting effects of food web stability; 2) that horizontal and vertical diversity have contrasting effects of chemicals on aquatic ecosystems. In addition, we found that warming temperature has a greater long term effect on stability of food webs than biodiversity. Overall, the thesis can provide a practical recommendation of how to conserve biodiversity to ensure stability and also of how to avoid anthropogenic impact.