Human-induced global stressors, including climate change, land use intensification, and the spread of invasive species, among others, have significant direct and indirect consequences for aquatic biological communities, physical and chemical processes, ecosystem and human health, and associated ecosystem services. Empirical, broad-scale (spatial and/or temporal) studies on multiple aquatic systems (tens to thousands) are key to improving our understanding of these complex issues across heterogeneous macroecological contexts and for the prediction and management of aquatic ecosystems’ responses to local and global changes. This session invites presentations about the ecological contexts of aquatic ecosystems and/or their responses to human-caused or mediated drivers at broad scales (regional to global) using insights from data-intensive approaches that include, but are not limited to, field surveys, remote sensing, machine learning, artificial intelligence, and statistical and process-based modeling.
Lead Organizer: Xinyu Sun, Michigan State University (sunxiny9@msu.edu)
Co-organizers:
Patrick Hanly, Michigan State University (hanlypat@msu.edu)
Kendra Cheruvelil, Michigan State University (ksc@msu.edu)
Patricia Soranno, Michigan State University (soranno@msu.edu)
Presentations
04:00 PM
GLOBAL-SCALE COMPILATION OF FRESHWATER ZOOPLANKTON: TINY SENTINELS OF ENVIRONMENTAL CHANGES (8292)
Primary Presenter: Stephanie Figary, University of Vermont & Cornell University (sef92@cornell.edu)
Zooplankton communities are the primary conduit of energy from phytoplankton to planktivorous fish in freshwater ecosystems and play key roles in the functioning of these systems. Therefore, they are often proposed as ecological indicators. However, most zooplankton research focuses on a single waterbody or region, and insights from such studies may not be transferable to other waterbodies. To address this knowledge gap, the Zooplankton as Indicators Group (ZIG) of the Global Lake Ecological Observatory Network (GLEON) assembled a zooplankton dataset that also includes physical and chemical lake characteristics. The dataset has a broad spatial and temporal coverage with data from over 290 waterbodies. Each waterbody includes 1 to 60 years of data, with >70% sampled at least monthly during the growing season (>31,000 sampling events represented). We are exploring the environmental drivers of zooplankton community composition and assessing zooplankton as ecological indicators using this new dataset. Further, we are investigating whether relationships between zooplankton metrics and environmental drivers differ among lake characteristics (e.g., deep vs shallow) or regions, including systems such as the Laurentian Great Lakes, mountain lakes, and tropical lakes. Understanding the linkages between zooplankton communities and environmental drivers is essential to forecasting the future state of freshwaters in a changing world and we expect the dataset to have extensive and versatile applications in examining zooplankton dynamics and ecosystem responses to environmental shifts.
04:15 PM
ENVIRONMENTAL DRIVERS OF NIGHT VERSUS DAY ZOOPLANKTON POPULATION ESTIMATES IN LAKES AROUND THE WORLD (8073)
Primary Presenter: Jonathan Doubek, Lake Superior State University (jdoubek@lssu.edu)
Zooplankton play vital roles in aquatic food webs by grazing on phytoplankton, which affects water quality, and transferring energy to higher trophic levels. In freshwater lakes, zooplankton commonly exhibit diel vertical and horizontal migration. During the day, zooplankton descend to deeper waters, or seek refuge in littoral areas or the sediment-water interface, to avoid visual predators, and then migrate to open water at night to feed. Consequently, zooplankton may exhibit higher density and biomass at night versus the day, and estimates and perceptions of zooplankton dynamics can change with the time of day sampling occurs. To better understand these diel zooplankton differences and their environmental drivers, we conducted a standardized global campaign to sample crustacean zooplankton in the full water column at day and night in the pelagic zone of 40 lakes. The lakes spanned a gradient in trophic state, size, and other variables such as dissolved oxygen (DO). Mesotrophic and eutrophic lakes exhibited greater zooplankton biomass at night versus day while oligotrophic lakes did not. Crustacean zooplankton had higher biomass at night versus day in lakes at lower elevation, with higher chlorophyll a concentration, and lower hypolimnetic DO levels. Lake area and depth were not related to diel zooplankton density or biomass. We provide one of the first global, standardized studies on environmental drivers of day versus night zooplankton population estimates. This study has important ramifications for our understanding of zooplankton ecology and for sampling regimens.
04:30 PM
DO ZOOPLANKTON DIVERSITY-ENVIRONMENT RELATIONSHIPS DERIVED FROM SPACE-FOR-TIME-SUBSTITUTION SURVEYS ACTUALLY REPRESENT ANY LAKES? (7960)
Primary Presenter: Jason Stockwell, University of Vermont (jason.stockwell@uvm.edu)
Space-For-Time-Substitution (SFTS) surveys are used to describe zooplankton community structure, assess lake health, and forecast lake responses to environmental change. SFTS surveys combine single-point sampling from many lakes to evaluate zooplankton community structure and dynamics (e.g., abundance, diversity) and their responses to ecogeographical gradients in key environmental drivers (e.g., temperature, salinity), instead of tracking such responses in individual lakes. However, the reliability and reproducibility of estimating temporal dynamics from models of SFTS survey data have yet to be tested against observed community dynamics within lakes distributed worldwide. We use a recently compiled global dataset (292 lakes, 38 countries, 6 continents) of lake zooplankton time series to estimate the relationship between zooplankton diversity and potential environmental drivers using simulated SFTS surveys. We then apply the results to lakes with long-term time series to compare relationships derived from SFTS surveys with the historical dynamics of individual lakes. We expect that zooplankton dynamics in lakes from less variable thermal regions (i.e., low and high latitudes) will not be well represented by temperature relationships derived from SFTS surveys. Testing biodiversity-ecosystem function relationships and their drivers requires adequate temporally and spatially resolved data. We provide a global perspective on the design of monitoring programs that include zooplankton and examine the reliability of zooplankton biodiversity patterns observed in SFTS surveys.
04:45 PM
Contrasting spatial and temporal patterns of zooplankton diversity to test space-for-time substitution in lakes (7974)
Primary Presenter: Daniel Edwards, Iowa State University (dje@iastate.edu)
Understanding of how biological communities respond to environmental change is of critical import to predicting future biodiversity scenarios and prioritizing management efforts. However, our understanding of how communities contend with stressors under realistic conditions is challenged by a lack of long-term data capturing biological responses to changing conditions. Given this limitation, researchers frequently rely on spatial patterns (i.e., environmental and biotic differences between sites) to infer potential consequences of environmental changes over time. But despite the ubiquity of space-for-time substitution, the underlying assumption that communities will respond to changes over time in the same way as they respond to comparable spatial gradients has rarely been tested. Addressing this knowledge gap, we leverage long-term zooplankton and water quality data from over 120 lakes sampled for nearly 25 years as part of the Iowa Ambient Lake Monitoring Program. Relationships between zooplankton biodiversity and several water quality variables (including temperature and nutrient concentrations) were assessed, using a series of mixed-effect models to contrast spatial and temporal responses to environmental gradients. This unique, long-term data resource provided a valuable opportunity to test key assumptions of the space-for-time substitution approach and develop empirical insights to support its broader use.
05:00 PM
Common processes drive metacommunity structure in freshwater lake fish (7874)
Primary Presenter: Taku Kadoya, National Institute for Environmental Studies (kadoya@nies.go.jp)
Environmental change affects metacommunity structure both directly—via abiotic factors and dispersal that affect species occurrence—and indirectly—via complex interactions among co-occurring species. Here, we examined how the three main metacommunity factors—environmental conditions, spatial processes, and species associations—affect metacommunity structure and whether responses are predictable in real-world systems by using novel methods to disentangle the drivers. We used a dataset of freshwater fish species occurrences in temperate lakes in three countries in different biogeographic regions to demonstrate that environmental processes are the main drivers of species’ distribution and diversity. The result suggests that future climate change (anthropogenic alteration of abiotic factors) will heavily influence the structure of metacommunities. We also showed that spatial processes and species interactions mediated the influence of environmental processes, especially at the lake level, suggesting that ongoing changes in metacommunity structure are modulated not only by the direct impacts of shifting abiotic factors but also by indirect effects of species interactions. Our global analysis indicates that even under the current high rate of environmental change, an identifiable set of underlying processes can be used to predict impacts of this change on metacommunity structure.
05:15 PM
Assessing land use, trait, and phylogenetic influences on invasive freshwater fishes in National Ecological Observation Network (NEON) sites (7989)
Primary Presenter: Angela Strecker, Western Washington University (angela.strecker@wwu.edu)
Studying community invasion ecology is integral to understanding how biotic and abiotic factors increase invasion success. Our research focused on freshwater fish communities and ecological interactions across 28 National Ecological Observatory Network (NEON) aquatic sites. NEON data provide the opportunity to assess spatial differences between uniformly-sampled field sites across the United States. We analyzed the influence of phylogenetic diversity, functional traits, and land use on invasion response metrics with beta regression models. Invasion response variables included relative abundance of invasive taxa and relative invasive richness. Average temperature range of all species at each site was the only variable found to be related to invasion, with lower densities of invaders when fishes had a higher thermal range. No significant correlations were found between invasion metrics and phylogenetic relatedness, fecundity, trophic level, body size or land use. Our study demonstrates the benefits of continental-scale, coordinated datasets to answer ecological questions, including developing a better understanding of the broad-scale drivers of aquatic invasions.
SS17C - Data-Intensive Research Builds Understanding of Aquatic Ecosystem Responses to Change at Regional to Global Scales
Description
Time: 4:00 PM
Date: 4/6/2024
Room: Hall of Ideas I