A5014139923- Aquatic Ecosystems and Phytoplankton Dynamics
- Marine and coastal ecosystems
- Soil and Water Nutrient Dynamics
- Arctic and Antarctic ice dynamics
- Fish Ecology and Management Studies
- Cryospheric studies and observations
- Climate change and permafrost
- Aquatic Invertebrate Ecology and Behavior
- Hydrology and Watershed Management Studies
- Microbial Community Ecology and Physiology
- Freshwater macroinvertebrate diversity and ecology
- Water Quality and Pollution Assessment
- Atmospheric and Environmental Gas Dynamics
- Oceanographic and Atmospheric Processes
- Soil erosion and sediment transport
- Coastal wetland ecosystem dynamics
- Environmental Toxicology and Ecotoxicology
- Freezing and Crystallization Processes
- Research Data Management Practices
- Injury Epidemiology and Prevention
- Modular Robots and Swarm Intelligence
- Polar Research and Ecology
- Urban Heat Island Mitigation
- Peatlands and Wetlands Ecology
- Material Properties and Processing
Miami University
2003-2024
University of Minnesota
2016-2023
Itasca Consultants (United States)
2016-2023
Michigan State University
2005-2010
Georgia Institute of Technology
2008
We explore the role of lakes in carbon cycling and global climate, examine mechanisms influencing pools transformations lakes, discuss how metabolism inland waters is likely to change response climate. Furthermore, we project changes as climate abundance spatial distribution biosphere, revise estimate for extent transformation waters. This synthesis demonstrates that annual emissions dioxide from atmosphere are similar magnitude uptake by oceans burial organic water sediments exceeds...
Abstract Increases in terrestrially-derived dissolved organic matter (DOM) have led to the browning of inland waters across regions northeastern North America and Europe. Short-term experimental comparative studies highlight important ecological consequences browning. These range from transparency-induced increases thermal stratification oxygen (O 2 ) depletion changes pelagic food web structure alteration role global carbon cycle. However, multi-decadal that document net long-term are...
Abstract People extensively use lakes and rivers covered by seasonal ice. Although ice cover duration has been declining over the past 150 years for Northern Hemisphere freshwaters, we know relatively little about how loss directly affects humans. Here, synthesize cultural ecosystem services (i.e., that provide intangible or nonmaterial benefits) associated benefits supported inland We also provide, first time, empirical examples give quantitative evidence a winter warming effect on wide...
Abstract Lake surfaces are warming worldwide, raising concerns about lake organism responses to thermal habitat changes. Species may cope with temperature increases by shifting their seasonality or depth track suitable habitats, but these be constrained ecological interactions, life histories limiting resources. Here we use 32 million measurements from 139 lakes quantify change (percentage of non-overlap) and assess how this is exacerbated potential constraints. Long-term resulted in an...
Abstract Cyanobacterial blooms have substantial direct and indirect negative impacts on freshwater ecosystems including releasing toxins, blocking light needed by other organisms, depleting oxygen. There is growing concern over the potential for climate change to promote cyanobacterial blooms, as positive effects of increasing lake surface temperature growth are well documented in literature; however, there evidence that also being initiated persisting relatively cold‐water temperatures...
Globally, lake surface water temperatures have warmed rapidly relative to air temperatures, but changes in deepwater and vertical thermal structure are still largely unknown. We compiled the most comprehensive data set date of long-term (1970-2009) summertime temperature profiles lakes across world examine trends drivers whole-lake structure. found significant increases at an average rate + 0.37 °C decade-1, comparable reported previously for other lakes, similarly consistent increasing...
As the lowest point in surrounding landscape, lakes act as sensors landscape to provide insights into response of both terrestrial and aquatic ecosystems climate change. Here a novel suite forcing optical indices (CFOI) from across North America is found respond changes air temperature, precipitation, solar radiation at timescales ranging single storm event seasonal longer‐term interdecadal trends with regression r 2 values 0.73 0.89. These are based on two metrics dissolved organic carbon...
Lake surface water temperatures are warming worldwide, raising concerns about the future integrity of valuable lake ecosystem services. In contrast to temperatures, we know far less what is happening temperature beneath surface, where most organisms live. Moreover, little which characteristics make lakes more or sensitive climate change and other environmental stressors. We examined changes in thermal structure for 231 across northeastern North America (NENA), a region with an exceptionally...
Abstract The quality of lake ice is uppermost importance for safety and under-ice ecology, but its temporal spatial variability largely unknown. Here we conducted a coordinated sampling campaign across the Northern Hemisphere during one warmest winters since 1880 show that 2020/2021 commonly consisted unstable white ice, at times contributing up to 100% total thickness. We observed increased over winter season, becoming thickest constituting largest proportion layer towards end cover season...
We investigated how watershed land use (a gradient of agricultural vs. forested land) relates to phytoplankton primary production (PPr) and photosynthetic parameters in 12 reservoirs Ohio examined spatial variation these parameters. Shallow sites near stream inflows had higher light attenuation, total phosphorus (TP), chlorophyll, nonvolatile suspended solids (NVSS), light‐saturated photosynthesis (P B m ), volumetric PPr than deeper dam outflows, but areal the initial slope...
Animals can be important in nutrient cycling particular ecosystems, but few studies have examined how this importance varies along environmental gradients. In study we quantified the role of an abundant detritivorous fish species, gizzard shad (Dorosoma cepedianum), reservoir ecosystems a gradient ecosystem productivity. Gizzard feed mostly on sediment detritus and excrete sediment-derived nutrients into water column, thereby mediating cross-habitat translocation to phytoplankton. We...
Sediment organic carbon (C) burial and CO 2 fluxes in inland waters are quantitatively important regional global budgets. Estimates of C from typically based on limited temporal resolution despite potential large variations with season weather events. Further, most freshwater budget studies have focused natural soft‐water lakes, while reservoirs hard‐water systems globally numerous. Our study quantifies two hard‐water, human constructed (Ohio, USA) contrasting watershed land use (agriculture...
Abstract Surface water temperatures are warming in many lakes across the globe, and this is widely attributed to air temperatures. Yet two Pennsylvania (USA) have shown long‐term increases surface over past 27 summers during a period with no significant increase regional temperature. We examined relationship between trends seven metrics of whole‐lake thermal structure several potential driver variables. Driver variables included transparency, lake pH, meteorological Both exhibited...
Abstract Winter is an important season for many limnological processes, which can range from biogeochemical transformations to ecological interactions. Interest in the structure and function of lake ecosystems under ice on rise. Although limnologists working at polar latitudes have a long history winter work, required knowledge successfully sample conditions not widely available relatively few receive formal training. In particular, deployment operation equipment below 0°C temperatures pose...
We report a reversal in the sign of herbivore‐phytoplankton interaction between zebra mussel ( Dreissena polymorpha ) and Microcystis aeruginosa , harmful planktonic cyanobacterium. A pair large‐scale manipulations density same lake consecutive years showed that when phosphorus concentrations were very low (mean total [TP] ~ 3 µg L −1 ), effect on biomass M. was monotonically negative across full range sustainable densities. When enclosures fertilized with TP 9 there positive gradient. These...
We investigated whether concentrations of the cyanobacterial toxin microcystin were positively associated with Dreissena polymorpha invasion by conducting surveys 39 inland lakes in southern Michigan low to moderate total phosphorus (≤20 µg·L –1 ). Lakes D. had 3.3 times higher and 3.6 biomass Microcystis aeruginosa (a major producer microcystin) than comparable without polymorpha. In contrast, Anabaena spp. (another potential was 4.6 also conducted a large-scale enclosure manipulation...
In recent decades, terrestrial dissolved organic matter (DOM) has increased in many northeastern North American and European lakes is contributing to long-term browning. We used a dataset (1988–2014) study the consequences of browning-related decreased water transparency on oxygen dynamics 2 small temperate Pennsylvania, USA, that differ their carbon concentrations. The oligotrophic ("clearer") lake low productivity historically oxygenated deep waters. mesotrophic–slightly dystrophic...
Winter activities on ice are culturally important for many countries, yet they constitute a high safety risk depending upon the stability of ice. Because consistently cold periods required to form stable and thick ice, warmer winters could degrade conditions increase likelihood falling through This study provides first large-scale assessment winter drowning from 10 Northern Hemisphere countries. We documented over 4000 events. drownings increased exponentially in regions with when air...
Storm events disproportionately mobilize dissolved phosphorus (P) compared to nitrogen (N), contributing reduction in load N:P. In agricultural watersheds, conservation tillage may lead even further declines N:P due P accumulation the top soil layers. Due an increase this management activity, we were interested impacts of on N and loads during storm events. Using a 20 year data set nutrient hypereutrophic reservoir, observed increasing relative base flow events, whereas proportional...
Abstract Winter conditions, such as ice cover and snow accumulation, are changing rapidly at northern latitudes can have important implications for lake processes. For example, snowmelt in the watershed—a defining feature of hydrology because it delivers a large portion annual nutrient inputs—is becoming earlier. Consequently, earlier shorter duration expected to affect phytoplankton biomass. To test this hypothesis, we developed an index runoff timing based on date when 50% cumulative...
In recent decades, lakes have experienced unprecedented ice loss with widespread ramifications for winter ecological processes. The rapid of ice, resurgence biology, and proliferation remote sensing technologies, presents a unique opportunity to integrate disciplines further understand the broad spatial temporal patterns in its consequences. Here, we summarize phenology records 78 12 countries across North America, Europe, Asia permit inclusion harmonization situ observations future...
Herbivores can have both direct (consumptive) and indirect (nutrient‐mediated) effects on primary producer biomass nutrient stoichiometry. Ecological stoichiometry theory predicts that herbivores of contrasting body will differentially remineralize nutrients, resulting in feedbacks We experimentally separated aquatic vertebrate grazers periphyton by manipulating grazer abundance identity mesocosms, using exclusion cages to expose recycled nutrients the absence grazing. In experiment 1, we...
Aquatic ecosystem management requires knowledge of the links among landscape-level anthropogenic disturbances and aquatic properties. With large catchment area to surface ratios (CA:SA), reservoirs often receive substantial terrestrial subsidies can be particularly sensitive eutrophication. Reservoir numbers attendant problems are increasing, tools needed categorize their eutrophication status. We analyzed a dataset 109 in Ohio (USA) an effort classify status using features reservoir...