The general goal of Roland Knapp's research is to understand how natural and anthropogenic factors influence the structure and function of aquatic ecosystems. The research questions he focuses on are the result of his interest in a particular ecosystem: California’s Sierra Nevada. Despite the critically important ecosystem services provided by this mountain range to millions of people, many aspects of Sierra Nevada aquatic ecosystems remain poorly understood. This lack of understanding undermines the ability to restore ecosystem structure and function and to anticipate how these ecosystems will respond to future stressors.