Coherent Dynamics among Lakes

Abstract

Abstract Historically, limnologists have analyzed and been concerned with lake status or condition; for example, classification by trophic status into eutrophic, oligotrophic, and dystrophic has allowed us to group lakes with similar properties and to study the causes and ramifications of those differences and similarities. However, in this era of awareness about global change, we have come to focus more on regional dynamics, particularly those that act at interannual or longer time scales. By combining spatial concepts that underlie differences between lakes with the time dimension, we can gain a better understanding of the determinants of lake dynamics that allow us to make more powerful predictions of trajectories into the future. Here we focus on the interannual time scale and explore how comparing similarities and differences in dynamics among years across lakes can enrich our understanding of lake dynamics and the processes that cause lakes to change. Many questions confront us in the quest to first describe and then understand long-term dynamics of suites of lakes. How should we characterize the coherent or shared dynamics of lakes? To what degree are interannual dynamics or long-term changes consistent among lakes? What determines how similarly or dissimilarly different lakes behave among years? Do adjacent lakes behave more similarly than more distant lakes? Do lakes of the same type or status, such as oligotrophic lakes, behave more similarly through time than different kinds of lakes, such as oligotrophic versus eutrophic? Are there common drivers of consistent dynamics among lakes such as dynamics in climate, land use, landform, or water flows? Are some types of lake parameters inherently more coherent than others?