Drivers and spatial structure of abiotic and biotic properties of lakes, wetlands, and streams at the national scale

Abstract

Broad‐scale studies have improved our ability to make predictions about how freshwater biotic and abiotic properties will respond to changes in climate and land use intensification. Further, fine‐scaled studies of lakes, wetlands, or streams have documented the important role of hydrologic connections for understanding many freshwater biotic and abiotic processes. However, lakes, wetlands, and streams are typically studied in isolation of one another at both fine and broad scales. Therefore, it is not known whether these three freshwater types (lakes, wetlands, and streams) respond similarly to ecosystem and watershed 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 ecosystem and watershed drivers and have similar spatial structure at the national scale? We answered this question with three U.S. conterminous data sets of freshwater ecosystems. We used random forest (RF) analysis to quantify the multi‐scaled drivers related to variation in nutrients and biota in lakes, wetlands, and streams simultaneously; we used semivariogram analysis to quantify the spatial structure of biotic and abiotic properties and to infer possible mechanisms controlling the ecosystem properties of these freshwater types. We found that abiotic properties responded to similar drivers, had large ranges of spatial autocorrelation, 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 smaller ranges of spatial autocorrelation. Our study is the first to document that drivers and spatial structure differ more between biotic and abiotic variables than across freshwater types, suggesting that some properties of freshwater ecosystems may respond similarly to future global changes.

Same species, same habitat preferences? The distribution of aquatic plants is not explained by the same predictors in lakes and streams

“…Nonetheless, the relative importance of climate in defining species habitat compared with the local environmental factors is somewhat poorly known in aquatic systems. Recently, King, Cheruvelil, and Pollard () showed that abiotic properties such as total phosphorus (TP) and total nitrogen (TN) values in U.S. lakes, streams, and wetlands were not dependent on water body categories; however, they demonstrated that percentage cover of aquatic vegetation was higher in lakes and wetlands, and lower in streams. Exploring factors that drive freshwater species distributions at various scales and in different ecosystems can improve our general understanding of species habitat preferences.…”

Landscape and biophysical controls of lake productivity to inform evaluation of sockeye salmon (Oncorhynchus nerka) populations in data‐limited regions

“…Across landscapes, watersheds integrate catchment-scale variation in hydrology and geomorphology, as well as regional forcings including climate, biogeography, and anthropogenic disturbance, producing regionally coherent patterns in trophic structure, organic material and nutrient delivery, and productivity (Fergus et al 2011;King et al 2019). On the Pacific coast of Alaska and British Columbia, lakes within the same biogeographic regions often share similar water chemistry, hydrology and climate, resulting in broad, regionally defined patterns of lake productivity (Stockner and MacIsaac 1996).…”

Rethinking Discretization to Advance Limnology in a Rapidly Changing World

“…By moving beyond research focused on single, discrete waterbody types, we have also begun to find the remarkable 4 commonalities among seemingly disparate aquatic ecosystem types leading to more general theories for how waterbodies function. For instance, waterbodies across size and flow gradients have been shown to have similar controls on their nutrient limitation (Elser et al, 2007), metabolism (Yvon-Durocher et al, 2012), trophic cascades (Shurin et al, 2002), and responses to human activity (King et al, 2019).…”

“…Numerous computing resources are putting advanced statistical tools at our finger tips for free. National, international, and global databases containing data from many thousands of waterbodies are inspiring new questions and becoming an increasingly important tool to understand aquatic ecosystems (King et al, 2019). And mobile technologies, social media, and open access philosophies are reshaping the ways limnologists communicate with each other and with the public.…”

“…These expectations can lead limnologists to form discrete, collaborative teams focused on illuminating exceptionally important research topics even if they are predominantly relevant only for specific waterbody types and zones. As a result, ponds, lakes, wetlands, streams, rivers, and oceans are typically studied in isolation at both fine and broad scales due to their perceived differences (Chaloner and Wotton 2011; King et al 2019).…”