A5029580927- Marine and coastal ecosystems
- Coastal wetland ecosystem dynamics
- Soil and Water Nutrient Dynamics
- Remote Sensing and LiDAR Applications
- Peatlands and Wetlands Ecology
- Marine Biology and Ecology Research
- Hydrology and Watershed Management Studies
- Isotope Analysis in Ecology
- Geology and Paleoclimatology Research
- Microbial Community Ecology and Physiology
- Fire effects on ecosystems
- Coastal and Marine Dynamics
- Fish Ecology and Management Studies
- Oceanographic and Atmospheric Processes
- Forest ecology and management
- Methane Hydrates and Related Phenomena
- Atmospheric and Environmental Gas Dynamics
- Marine and fisheries research
- Wastewater Treatment and Nitrogen Removal
- Groundwater and Isotope Geochemistry
- Cryospheric studies and observations
- Ocean Acidification Effects and Responses
- Soil erosion and sediment transport
- Climate change and permafrost
- Aeolian processes and effects
University of Georgia
2015-2025
University of Lethbridge
2013-2021
Marine Biological Laboratory
2002-2014
University of St Andrews
2013
Georgia Sea Grant
2012
Oregon State University
2010
US Forest Service
2006
Institut des Sciences Biologiques
2006
Ecosystem (Spain)
2004
Woods Hole Oceanographic Institution
2002
ABSTRACT Shifts in bacterioplankton community composition along the salinity gradient of Parker River estuary and Plum Island Sound, northeastern Massachusetts, were related to residence time bacterial doubling spring, summer, fall seasons. Bacterial was characterized with denaturing gel electrophoresis (DGGE) PCR-amplified 16S ribosomal DNA. Average calculated from production ([ 14 C]leucine incorporation) abundance (direct counts). Freshwater marine populations advected into represented a...
This article outlines an approach, based on ecosystem services, for assessing the trade-offs inherent in managing humans embedded ecological systems. Evaluating these requires understanding of biophysical magnitudes changes services that result from human actions, and impact welfare. We summarize state art services–based management information needs applying it. Three case studies Long Term Ecological Research (LTER) sites—coastal, urban, agricultural—illustrate usefulness, needs,...
The northeastern United States receives elevated inputs of anthropogenic nitrogen (N) largely from net imports food and atmospheric deposition, with lesser fertilizer, feed imports, N fixation associated leguminous crops. Ecological consequences to the Northeast include tropospheric ozone formation, damage plants, alteration forest cycles, acidification surface waters, eutrophication in coastal waters. We used two models, PnET-BGC WATERSN, evaluate management strategies for reducing forests...
A mixing model derived from first principles describes the bulk density (BD) of intertidal wetland sediments as a function loss on ignition (LOI). The assumes that volume sediment equates to sum self-packing volumes organic and mineral components or BD = 1/[LOI/k1 + (1-LOI)/k2], where k1 k2 are densities pure inorganic components, respectively. explained 78% variability in total when fitted 5075 measurements drawn 33 wetlands distributed around conterminous United States. values were...
We present a conceptual approach for evaluating the biological and hydrological controls of nutrient removal in different sized rivers within an entire river network. emphasize per unit area parameter, uptake velocity (ν f ), which is mathematically independent size benthic dominated systems. Standardization parameters from previous network models to ν reveals nature dependant activity these models. explore how geomorphic, hydraulic, factors control distribution idealized network, finding...
Seasonal patterns of aboveground plant mass and the depth distribution live roots, rhizomes, dead belowground organic matter were measured for Spartina alterniflora cynosuroides in Georgia tidal marshes. Peak biomass was 1.6 × higher S. than alterniflora. Live 2.4 more 1.7 Rhizomes made up 76 87% during year. Mirrored accumulation loss above‐ tissues year suggest importance seasonal storage redistribution matter. Belowground production with a technique that partially accounts midseason...
Stable isotope measurements of carbon were used to study the transfer from phytoplankton bacteria during an experimental diatom bloom. A large-volume tank was filled with 900 liters 10-µm-filtered seawater Woods Hole Harbor, and N, P, Si nutrients as well 13C-enriched NaHCO3 added. This resulted in a high nutrient system label +85‰ dissolved inorganic pool. Algal growth depleted near-zero concentrations midway through 2-week experiment little net organic C (DOC) accumulation; algal...
Results of a 2—yr evaluation aboveground production 7 plant species commonly found in Louisiana's coastal marshes show generally higher level compared to other studies. In 5 the significant growth occurred throughout year. Calculated annual grams per square metre for each was; Distichlis spicata–3237; Juncus roemerianus–3416; Phragmites communis–2318; Sagittaria falcata–1501; Spartina alterniflora–2658; cynosuroids—1355; and patens–6043. Sampling variability, expressed as ratio standard...
Abstract With sea level rise accelerating and sediment inputs to the coast declining worldwide, there is concern that tidal wetlands will drown. To better understand this concern, sources of contributing marsh elevation gain were computed for Plum Island Sound estuary, MA, USA. We quantified input from rivers erosion edges. Maintaining relative recent rate 2.8 mm yr −1 requires 32,299 MT sediment. The watersheds only 3,210 . Marsh edge erosion, based on a comparison 2005 2011 LiDAR data,...
Abstract The magnitude, spatiotemporal patterns, and controls of carbon flux from land to the ocean remain uncertain. Here we applied a process‐based model with explicit representation processes in streams rivers examine how changes climate, conversion, management practices, atmospheric CO 2 , nitrogen deposition affected fluxes eastern North America Atlantic Ocean, specifically Gulf Maine (GOM), Middle Bight (MAB), South (SAB). Our simulation results indicate that mean annual (±1 standard...