Broad-scale studies have improved scientists’ ability to make predictions about how freshwater biotic and abiotic properties may respond to changes in climate and land use intensification. However, studies at macroscales (e.g. regions to continents) are not possible without large datasets that often come from state and federal monitoring programs. Further, datasets and studies across freshwater types, such as, lakes, wetlands, and streams are rare, and therefore, it is not known whether these freshwater ecosystems respond similarly to local and regional drivers nor how they may respond to future global stresses. In this study, we asked: do lake, wetland, and stream biotic and abiotic properties respond to similar local and regional drivers at macroscales? We answered this question with the US EPA’s National Aquatic Resource Surveys (NARS) for all three freshwater types at the U.S. conterminous scale. We used random forest analysis to quantify the multi-scaled drivers that were related to variation in nutrients and biota in lakes, wetlands, and streams simultaneously; and we used semivariogram analysis to quantify the spatial structure of biotic and abiotic properties and their drivers to further investigate the influence of the top drivers.
Results/Conclusions
Random forest models showed that abiotic properties responded to similar multi-scale drivers and exhibited multi-scale spatial structure regardless of freshwater type. However, the dominant drivers of variation in biotic properties depended on freshwater type and had varying spatial structure. Our study suggests that freshwater ecosystems may respond similarly to future global changes.