A5026522217- Peatlands and Wetlands Ecology
- Soil and Water Nutrient Dynamics
- Hydrology and Watershed Management Studies
- Fish Ecology and Management Studies
- Coastal wetland ecosystem dynamics
- Freshwater macroinvertebrate diversity and ecology
- Botany and Plant Ecology Studies
- Atmospheric and Environmental Gas Dynamics
- Hydrology and Sediment Transport Processes
- Bioenergy crop production and management
- Marine and coastal ecosystems
- Water-Energy-Food Nexus Studies
- Groundwater and Isotope Geochemistry
- Geology and Paleoclimatology Research
- Fire effects on ecosystems
- Water Quality Monitoring Technologies
- Forest Management and Policy
- Mercury impact and mitigation studies
- CRISPR and Genetic Engineering
- Flood Risk Assessment and Management
- Climate change and permafrost
- Groundwater flow and contamination studies
- Bryophyte Studies and Records
- Insect Resistance and Genetics
- Soil erosion and sediment transport
Oak Ridge National Laboratory
2016-2025
National Technical Information Service
2023
Office of Scientific and Technical Information
2023
University of Notre Dame
2007-2017
Abstract Peatlands contain one-third of soil carbon (C), mostly buried in deep, saturated anoxic zones (catotelm). The response catotelm C to climate forcing is uncertain, because prior experiments have focused on surface warming. We show that deep peat heating a 2 m-thick column results an exponential increase CH 4 emissions. However, this due solely processes and not degradation peat. Incubations only the top 20–30 cm from experimental plots higher production rates at elevated...
An experiment in >1000 river and riparian sites found spatial patterns controls of carbon processing at the global scale.
Corn ( Zea mays L.) that has been genetically engineered to produce the Cry1Ab protein (Bt corn) is resistant lepidopteran pests. Bt corn widely planted in midwestern United States, often adjacent headwater streams. We show byproducts, such as pollen and detritus, enter streams are subject storage, consumption, transport downstream water bodies. Laboratory feeding trials showed consumption of byproducts reduced growth increased mortality nontarget stream insects. Stream insects important...
Streams and rivers are important conduits of terrestrially derived carbon (C) to atmospheric marine reservoirs. Leaf litter breakdown rates expected increase as water temperatures rise in response climate change. The magnitude is uncertain, given differences quality microbial detritivore community responses temperature, factors that can influence the apparent temperature sensitivity relative proportion C lost atmosphere vs. stored or transported downstream. Here, we synthesized 1025 records...
Abstract Headwater streams remove, transform, and store inorganic nitrogen (N) delivered from surrounding watersheds, but excessive N inputs human activity can saturate removal capacity. Most research has focused on quantifying the water column over short periods in individual reaches, these ecosystem‐scale measurements suggest that assimilatory uptake accounts for most removal. However, cross‐system comparisons addressing relative role of particular biota responsible incorporating into...
Abstract To evaluate boreal peatland C losses from warming, novel technologies were used to expose intact bog plots in northern Minnesota a range of future temperatures (+0°C +9°C) with and without elevated CO 2 (eCO ). After 3 years, warming linearly increased net loss at rate 31.3 g C·m −2 ·year −1 ·°C . Increasing associated decomposition corroborated by measures declining peat elevation. Effects eCO minor. Results indicate peatlands 4.5 18 times faster than historical rates accumulation,...
Abstract A national-scale quantification of metabolic energy flow in streams and rivers can improve understanding the temporal dynamics in-stream activity, links between cycling ecosystem services, effects human activities on aquatic metabolism. The two dominant terms metabolism, gross primary production (GPP) aerobic respiration (ER), have recently become practical to estimate for many sites due improved modeling approaches availability requisite model inputs public datasets. We assembled...
Significance While peatlands have historically stored massive amounts of soil carbon, warming is expected to enhance decomposition, leading a positive feedback with climate change. In this study, unique whole-ecosystem experiment was conducted in northern Minnesota warm peat profiles 2 m deep while keeping water flow intact. After nearly y, enhanced the degradation organic matter and increased greenhouse gas production. Changes quality were accompanied by stimulation methane production...
Abstract Ebullitive methane (CH 4 ) emissions in lentic ecosystems tend to concentrate at river‐lake interfaces and within shallow littoral zones. However, inconsistent definitions of the zone static representations lake or reservoir surface area contribute major uncertainties greenhouse gas (GHG) estimates, particularly reservoirs with large water‐level fluctuations. This study examines temporal variation total areas US demonstrates how different methods data sources lead discrepencies GHG...
Widespread planting of maize throughout the agricultural Midwest may result in detritus entering adjacent stream ecosystems, and 63% 2009 US crop was genetically modified to express insecticidal Cry proteins derived from Bacillus thuringiensis . Six months after harvest, we conducted a synoptic survey 217 sites Indiana determine extent presence Cry1Ab protein network. We found that 86% contained leaves, cobs, husks, and/or stalks active channel. also detected stream-channel at 13% water...
We present a comprehensive data set of gross primary production (GPP) and ecosystem respiration (ER) in open‐canopy, nutrient‐rich streams draining row‐crop agriculture the midwestern United States. used two approaches to characterize temporal spatial variation whole‐stream metabolism: continuous measurements one agricultural stream for 1 yr, periodic daily six on dates spanning summer, autumn, winter. Continuous revealed high rates GPP (range: 0.1 22.0 g O 2 m −2 d −1 ) ER −0.9 −34.8 that...
Abstract. Predictive understanding of northern peatland hydrology is a necessary precursor to the fate massive carbon stores in these systems under influence present and future climate change. Current models have begun address microtopographic controls on hydrology, but none included prognostic calculation water table depth for vegetated wetland, independent prescribed regional tables. We introduce here new configuration Community Land Model (CLM) which includes fully peatland. Our...
Abstract The increasing demand for bioenergy crops presents our society with the opportunity to design more sustainable landscapes. We have created a Biomass Location Optimal Sustainability Model (BLOSM) test hypothesis that landscape of cellulosic crop plantings may simultaneously improve water quality (i.e. decrease concentrations sediment, total phosphorus, and nitrogen) increase profits farmer‐producers while achieving feedstock‐production goal. BLOSM was run using six scenarios identify...
We used a natural temperature gradient in Walker Branch, spring-fed forested stream eastern Tennessee, USA, to examine the influence of on organic-matter decomposition. In this stream, upstream sites are warmer than downstream winter and cooler summer. cotton-strip assay breakdown substrate uniform quality (95% cellulose) along monthly for 2 y. also litter bags interactive effects leaf-litter (labile red maple [Acer rubrum] tulip poplar [Liriodendron tulipifera] less labile white oak...
Rivers and streams contribute to global carbon cycling by decomposing immense quantities of terrestrial plant matter. However, decomposition rates are highly variable large-scale patterns drivers this process remain poorly understood. Using a cellulose-based assay reflect the primary constituent detritus, we generated predictive model (81% variance explained) for cellulose across 514 globally distributed streams. A large number variables were important predicting decomposition, highlighting...
Headwater streams draining agricultural landscapes receive maize leaves ( Zea mays L.) via wind and surface runoff, yet the contribution of detritus to organic‐matter processing in is largely unknown. We quantified decomposition microbial respiration rates on conventional (non‐Bt) genetically engineered (Bt) three low‐order northwestern Indiana, USA. also examined how substrate quality in‐stream nutrient concentrations influenced by comparing red maple Acer rubrum ) nutrient‐rich...
In the midwestern United States, maize detritus enters streams draining agricultural land. Genetically modified Bt is commonly planted along and can possibly affect benthic macroinvertebrates, specifically members of order Trichoptera, which are closely related to target species some toxins important detritivores in streams. The significance inputs aquatic systems has only recently been recognized, assessments potential nontarget impacts on organisms lacking. We conducted laboratory feeding...
Channelized streams are common in North American agricultural regions, where they minimize water residence time and biological nutrient processing. Floodplain restoration done via the 2-stage-ditch management strategy can improve channel stability retention during storms. We examined influence of floodplain on whole-stream metabolism by measuring gross primary production (GPP) ecosystem respiration (ER) for 1 y before 4 after an upstream, unaltered control reach a downstream, restored reach....
Abstract. The time and geographic sources of streamwater in low-relief watersheds are poorly understood. This is partly due to the difficult combination low runoff coefficients often damped isotopic signals precluding traditional hydrograph separation convolution integral approaches. Here we present a dual-isotope approach involving 18O 2H water low-angle forested watershed determine source components then build conceptual model streamflow generation. We focus on three headwater lowland...
Anthropogenic increases in nitrogen (N) and phosphorus (P) concentrations can strongly influence the structure function of ecosystems. Even though lotic ecosystems receive cumulative inputs nutrients applied to deposited on land, no comprehensive assessment has quantified nutrient-enrichment effects within streams rivers. We conducted a meta-analysis published studies that experimentally increased N and/or P rivers examine how enrichment alters ecosystem (state: primary producer consumer...