A5052485893- Coastal wetland ecosystem dynamics
- Coastal and Marine Dynamics
- Plant Water Relations and Carbon Dynamics
- Geology and Paleoclimatology Research
- Peatlands and Wetlands Ecology
- Coastal and Marine Management
- Ecosystem dynamics and resilience
- Aeolian processes and effects
- Hydrology and Watershed Management Studies
- Marine and coastal ecosystems
- Tropical and Extratropical Cyclones Research
- Tree-ring climate responses
- Lattice Boltzmann Simulation Studies
- Geological formations and processes
- Isotope Analysis in Ecology
- Soil and Unsaturated Flow
- Groundwater and Isotope Geochemistry
- Atmospheric and Environmental Gas Dynamics
- Climate Change, Adaptation, Migration
- Plant responses to elevated CO2
- Fire effects on ecosystems
- Soil erosion and sediment transport
- Climate change and permafrost
- Rangeland and Wildlife Management
- Horticultural and Viticultural Research
US Forest Service
2017-2018
United States Geological Survey
2012-2017
U.S. Geological Survey, Wetland and Aquatic Research Center
2017
Pacific Island Ecosystems Research Center
2013
Everglades University
2010-2011
National Park Service
2006
Columbia University
1999-2005
Lamont-Doherty Earth Observatory
1999-2005
Duke University
2003
Disturbances are important for renewal of North American forests. Here we summarize more than 180 site years eddy covariance measurements carbon dioxide flux made at forest chronosequences in America. The disturbances included stand‐replacing fire (Alaska, Arizona, Manitoba, and Saskatchewan) harvest (British Columbia, Florida, New Brunswick, Oregon, Quebec, Saskatchewan, Wisconsin) events, insect infestations (gypsy moth, tent caterpillar, mountain pine beetle), Hurricane Wilma,...
Hydrologic processes control much of the export organic matter and nutrients from land surface. It is variability these hydrologic that produces variable patterns nutrient transport in both space time. In this paper, we explore how “connectivity” potentially affects transport. connectivity defined as condition by which disparate regions on hillslope are linked via subsurface water flow. We present simulations suggest for year, draining through a catchment spatially isolated. Only rarely,...
Abstract. Despite the importance of mangrove ecosystems in global carbon budget, relationships between environmental drivers and dynamics these forests remain poorly understood. This limited understanding is partly a result challenges associated with situ flux studies. Tower-based CO2 eddy covariance (EC) systems are installed only few worldwide, longest EC record from Florida Everglades contains less than 9 years observations. A primary goal present study was to develop methodology estimate...
Abstract Measurements of photosynthesis and respiration were made on leaves in summer a Quercus rubra L. canopy at approximately hourly intervals throughout 5 days nights. Leaves selected the upper fully sunlit conditions (upper) lower (lower). In addition, shaded (upper shaded) to decrease rates. The data used test hypothesis that total night‐time is dependent during previous day response mediated through changes storage carbohydrate pools. clear sunny with similar solar irradiance air...
Abstract Mangrove forests are highly productive ecosystems, but the fate of mangrove‐derived carbon remains uncertain. Part that uncertainty stems from fact gas transfer velocities in mangrove‐surrounded waters not well determined, leading to air‐water CO 2 fluxes. Two SF 6 tracer release experiments were conducted determine ( k (600) = 8.3 ± 0.4 and 8.1 0.6 cm h −1 ), along with simultaneous measurements pCO fluxes Shark River, Florida (232.11 23.69 171.13 20.28 mmol C m −2 d an estuary...
Abstract. The Shark and Harney rivers, located on the southwest coast of Florida, USA, originate in freshwater, karstic marshes Everglades flow through largest contiguous mangrove forest North America. In November 2010 2011, dissolved carbon source–sink dynamics was examined these rivers during SF6 tracer release experiments. Approximately 80 % total flux out experiments form inorganic carbon, either via air–water CO2 exchange or longitudinal (DIC) to coastal ocean. Between 42 48...
Abstract Knowledge of gas exchange in wetlands is important order to determine fluxes climatically and biogeochemically trace gases conduct mass balances for metabolism studies. Very few studies have been conducted quantify transfer velocities wetlands, many wind speed/gas parameterizations used oceanographic or limnological settings are inappropriate under conditions found wetlands. Here six measurements made with SF 6 tracer release experiments three different years the Everglades, a...
[1] Wetland ecosystems are often characterized by distinct vegetation patterns. Various mechanisms have been proposed to explain the formation of these patterns; including spatially variable peat accumulation and water ponding. Recently, short-range facilitation long-range competition for resources (a.k.a scale dependent feedback) has as a possible mechanism pattern in wetland ecosystems. We modify an existing, explicit, advection-reaction-diffusion model include regional hydraulic gradient...
This study presents two new modeling strategies. First, a methodology for representing the physical process of subsurface storm flow within TOPMODEL framework is developed. In using this approach, discharge at quick timescales simulated, and fuller depiction hydrologic activity brought about. Discharge water from vadose zone permitted in physically realistic manner without priori assumption level soil column which saturation can take place. Determination contribution to made equation...
Surface water flow dynamics in the Florida Everglades were investigated using sulfur hexafluoride tracer releases, from which advection and dispersion determined. Several sites studied, each characterized by different vegetation patterns proximity to hydrologic control structures. The measured directions suggest that basin‐scale forcing management structures operations can override effects of local landscape features guiding flow. Management particularly evident two regions where historic,...
Abstract We examined the effects of atmospheric vapor pressure deficit (VPD) and soil moisture stress (SMS) on leaf‐ stand‐level CO 2 exchange in model 3‐year‐old coppiced cottonwood ( Populus deltoides Bartr.) plantations using large‐scale, controlled environments Biosphere Laboratory. A short‐term experiment was imposed top continuing, long‐term treatments (43 120 Pa), at end growing season. For experiment, were exposed for 6–14 days to low high VPD (0.6 2.5 kPa) volumetric contents...
Abstract The Everglades is a low‐gradient floodplain predominantly on organic soil that undergoes seasonally pulsing sheetflow through network of deepwater sloughs separated by slightly higher elevation ridges. flow permitted the coexistence ridge and slough vegetation, including persistence productive, well‐connected concentrated prey supported wading bird nesting success. Here we review factors contributing to origin degradation ecosystem in an attempt answer “How much needed restore...
Information on sheet flow patterns in the marsh ridge and slough habitat of Florida Everglades is scarce, primarily because difficulty taking measurements across large enough spatial scales such a heterogeneous environment. As part Tracer Release Experiment (EverTREx), two SF 6 tracer releases were conducted to measure relatively intact habitats. The first was pilot experiment that allowed analytical equipment be tested Everglades, yielded some preliminary, coarse‐scale advection dispersion...