A5025487795- Plant Water Relations and Carbon Dynamics
- Fire effects on ecosystems
- Atmospheric and Environmental Gas Dynamics
- Coastal wetland ecosystem dynamics
- Atmospheric chemistry and aerosols
- Forest ecology and management
- Aeolian processes and effects
- Forest Biomass Utilization and Management
- Atmospheric aerosols and clouds
- Forest Management and Policy
- Peatlands and Wetlands Ecology
- Climate variability and models
- Marine and coastal ecosystems
- Plant responses to elevated CO2
- Coastal and Marine Dynamics
- Tree-ring climate responses
- Remote Sensing in Agriculture
- Flood Risk Assessment and Management
- Urban Heat Island Mitigation
- Species Distribution and Climate Change
- Climate change and permafrost
- Atmospheric Ozone and Climate
- Bioenergy crop production and management
- Ocean Acidification Effects and Responses
- Remote Sensing and LiDAR Applications
Clemson University
2017-2025
Sweet Briar College
2012-2015
Virginia Tech
2015
Oregon State University
2009-2011
University of Virginia
2004-2009
We report on net ecosystem production (NEP) and key environmental controls exchange (NEE) of carbon dioxide (CO 2 ) between a mangrove forest the atmosphere in coastal Florida Everglades. An eddy covariance system deployed above canopy was used to determine NEE during January 2004 through August 2005. Maximum daytime ranged from −20 −25 μ mol m −2 s −1 March May. Respiration (R d highly variable (2.81 ± 2.41 ), reaching peak values summer wet season. During winter dry season, CO assimilation...
Disturbance processes of various types substantially modify ecosystem carbon dynamics both temporally and spatially, constitute a fundamental part larger landscape‐level dynamics. Forests typically lose for several years to decades following severe disturbance, but our understanding the duration post‐disturbance forest fluxes remains limited. Here we capitalize on recent North American Carbon Program disturbance synthesis discuss techniques future work needed better understand after...
Abstract Forest disturbances are major sources of carbon dioxide to the atmosphere, and therefore impact global climate. Biogeophysical attributes, such as surface albedo (reflectivity), further control climate‐regulating properties forests. Using both tower‐based remotely sensed data sets, we show that natural from wildfire, beetle outbreaks, hurricane wind throw can significantly alter albedo, associated radiative forcing either offsets or enhances CO 2 caused by reducing ecosystem...
The Northern Hemisphere's boreal forests, particularly the Siberian forest, may have a strong effect on Earth's climate through changes in dominant vegetation and associated regional surface albedo. We show that warmer will likely convert Siberia's deciduous larch (Larix spp.) to evergreen conifer thus decrease dynamic model, FAREAST, simulates Russian forest composition was used explore feedback between change at continental, regional, local scales. FAREAST simulate impact of temperature...
Abstract. Mapping in-situ eddy covariance measurements of terrestrial land-atmosphere fluxes to the globe is a key method for diagnosing Earth system from data-driven perspective. We describe first global products (called X-BASE) newly implemented up-scaling framework, FLUXCOM-X. The X-BASE comprise estimates CO2 net ecosystem exchange (NEE), gross primary productivity (GPP) as well evapotranspiration (ET) and, time, novel fully transpiration product (ETT), at high spatial (0.05°) and...
Abstract. Mapping in situ eddy covariance measurements of terrestrial land–atmosphere fluxes to the globe is a key method for diagnosing Earth system from data-driven perspective. We describe first global products (called X-BASE) newly implemented upscaling framework, FLUXCOM-X, representing an advancement previous generation FLUXCOM terms flexibility and technical capabilities. The X-BASE are comprised estimates CO2 net ecosystem exchange (NEE), gross primary productivity (GPP),...
Abstract. Volatile inorganic and size-resolved particulate Cl- Br-species were measured in near-surface air over a broad range of conditions within four distinct regimes (European – EURO, North African N-AFR, the Intertropical Convergence Zone ITCZ, South Atlantic S-ATL) along latitudinal gradient from 51° N to 18° S through eastern Ocean. Median dry-deposition fluxes sea salt, oxidized N, non-sea-salt varied by factors 25, 17, 9, respectively, among regimes. Sea-salt production was primary...
Abstract Aerodynamic canopy height ( h a ) is the effective of vegetation for its influence on atmospheric fluxes and key parameter surface‐atmosphere coupling. However, methods to estimate from data are limited. This synthesis evaluates applicability robustness calculation eddy covariance momentum‐flux data. At 69 forest sites, annual robustly predicted site‐to‐site year‐to‐year differences in heights R 2 = 0.88, 111 site‐years). 23 cropland/grassland weekly successfully captured dynamics...
Abstract Over 95% of original longleaf pine ( Pinus palustris ) (LLP) forests have been converted to other land uses, including loblolly taeda L (LOP), croplands, urban uses during the past two centuries in southeastern United States (U.S.) for socioeconomic developments. Restoring LLP represents a contemporary forest management objective improve wildlife habitat, water yield, and overall ecosystem services resilience changing climate. Given importance understanding ecohydrological processes...
Abstract. Due to the potential for land-use–land-cover change (LULCC) alter surface albedo, there is need within LULCC science community simple and transparent tools predicting radiative forcings (ΔF) from albedo changes (Δαs). To that end, kernel technique – developed by climate modeling diagnose internal feedbacks general circulation models (GCMs) has been adopted as a tool perform offline ΔF calculations Δαs. However, codes data behind GCM kernels are not readily transparent,...
Abstract. Mangrove forests are ecosystems susceptible to changing water levels and temperatures due climate change as well perturbations resulting from tropical storms. Numerical models can be used project mangrove forest responses regional global environmental changes, the reliability of these depends on surface energy balance closure. However, for tidal ecosystems, is complex because transport associated with activity remains poorly understood. This study aimed quantify impacts flows...
Abstract Forest disturbances can result in very different canopies that carry elevated albedo, thus causing substantial cooling effects on the climate. Unfortunately, resulting dynamic global warming potential from altered albedo (GWP Δα ) is poorly understood. We examined and modeled changes over time after (i.e., forest age) by type, disturbance type geographic location using direct measurements 107 sites temperate boreal regions. Albedo undisturbed forests was used as reference to...
Abstract. A semi-parametric PAR diffuse radiation model was developed using commonly measured climatic variables from 108 site-years of data 17 AmeriFlux sites. The has a logistic form and improves upon previous efforts larger set physically viable climate as predictors, including relative humidity, clearness index, surface albedo solar elevation angle. Model performance evaluated by comparison with simple cubic polynomial for the spectral range. outperformed an improved coefficient...
Abstract This paper examines albedo perturbation and radiative forcing after a high‐severity fire in mature forest the Oregon Cascade Range. Correlations between postfire seedling, sapling, snag (standing dead tree) density were investigated across severity classes seasons for years 4–15 fire. Albedo was 14 times larger winter compared to summer increased with class first several years. linearly time over study period. perturbations vegetation densities strongest snags, significant all both...
This paper examines data from 18 USGS gauges in the lower Pee Dee Basin an effort to explain behavior of flooding following Hurricane Florence (2018) Georgetown County, South Carolina. Despite record or near-record all tributaries Winyah Bay estuary, water levels near city were well below predicted heights. Floodplain storage Great Dee, Lynches, and Little River valleys stored over 1.2 million acre-feet floodwaters, delaying peak stage Bucksport for five days reducing flow into tidal...
Undeveloped forested wetlands in the valleys of coastal plain rivers can play a large role storing floodwater and attenuating river flooding. In lower Pee Dee, Little Lynches Rivers, these played mitigating downstream flooding following Hurricane Florence. Wetland forest flood mitigation was most effective for flows Great Dee River, where on former terraces determined course overbank flow potential storage floodwaters. Floodwater attenuation water level were less if larger limited to River....
Coastal ecosystems are vulnerable to climate change and have been identified as sources of uncertainty in the global carbon budget. Here we introduce a recently established mesonet eddy covariance towers South Carolina describe sensor arrays data workflow used produce three site-years flux observations coastal ecosystems. The tower sites represent tidal salt marsh (US-HB1), mature longleaf pine forest (US-HB2), restoration (replanted clearcut; US-HB3). remain less represented studies despite...