Alex T Chow

Alex T Chow
Clemson University | CU · Biogeochemistry & Enviromental Quality Research Group

Doctor of Philosophy in Hydrologic Science

About

118
Publications
31,032
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2,827
Citations
Additional affiliations
January 2010 - present
The Chinese University of Hong Kong
January 2009 - present
Clemson University
January 2003 - December 2009
University of California, Davis

Publications

Publications (118)
Article
Releases of hydrogen sulphide (H2S) and sulphur ions (S²⁻) through sulphate reduction in black-odorous waterbody is a great environmental health concern. Aquatic planting for blackening and odour controls has received great attention in research and practice. Nitrate concentration in black-odorous waterbody can vary significantly but little is know...
Article
Forested land plays an essential role in water supply across the United States (US). Smoldering commonly existing in wildfires contributes significantly to biomass consumption and gas emission, but its influence on source water quality has been rarely studied. Here, we investigated the impact of smoldering temperature (i.e., no burn, 250, 400, and...
Article
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Considerable recent research has confirmed that anthropogenic materials including microplastics and nanomaterials have been integrated into soil and dissolved organic matter in the environment. These pools of organic matter could be geochemically processed through different pathways and have different chemical and physical characteristics than the...
Article
Climate change is driving an increase in catastrophic wildfires; consumers see, smell, and taste the effects in their water. Water utilities must prepare for worse times ahead.
Article
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Microplastics (MPs) are widespread in natural ecosystems and have attracted considerable attention from scientists all over the world because they are believed to threaten every life form. In addition to their potential physical and chemical effects on organisms, MPs may act as a carrier for transferring many micropollutants including antibiotics,...
Article
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The byproducts of anaerobic biogeochemical processes, many mediated at the sediment–water interface, can degrade water quality in the bottom of reservoirs. Using both experimental sediment–water chambers and field monitoring, this study assessed nutrient and metals cycling in the profundal zone of hypereutrophic Hodges Reservoir, San Diego (maximum...
Article
Copper-based algaecides are usually used for controlling algae bloom triggered by the elevated levels of nutrients after wildfires, resulting in the promoted reactivity of dissolved organic matter (DOM) in forming disinfectant byproducts (DBPs). To identify the best strategy for handling this source water, we employed Fourier transform ion cyclotro...
Article
Globally, prescribed fire, harvesting, and understory mastication, alone and in combination, are common forest management practices. Timber commodities, wildlife habitat, wildfire fuel reduction, soil conservation, and water quality are frequently targeted and assessed as these practices are utilized. In the 1960s, a study of paired, first-order wa...
Article
Severe wildfires combust most above ground vegetation and detritus layers, altering the content and chemical composition of soil organic matter (SOM). To evaluate the lasting effects of wildfire on SOM and the recovery of burned soils, we sampled surface (Oa horizon) and mineral soils (0−5 and 5−15 cm depths) in unburned areas and areas burned at m...
Article
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While impervious surface expands with global urbanization, understanding the quality and quantity changes of soil organic carbon (SOC) under impervious surfaces is essential to assess the impacts of urbanization on the SOC pool and cycling. By comparing soils under impervious surfaces with surface and subsurface soils from adjoining open areas, we...
Article
In this study, we report for the first time the effect of prescribed fires on the export of dissolved organic matter (DOM) and precursors of disinfectant by-products (DBPs) from periodically (every 2-3 years) and seasonally (i.e., dormant and growing) burned forest fuel materials (i.e., live vegetation, woody debris, and detritus [litter and duff])...
Article
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Decomposing foliar litter organic matter (LOM) in forested watersheds is an essential terrestrial source of dissolved organic matter (DOM) to aquatic ecosystems. To evaluate the relationship of chemical composition between LOM and DOM, we collected freshly fallen leaves of white oak (Quercus alba) and conducted an 80-week field decomposition experi...
Preprint
Full-text available
Accepted to Forest Ecology and Management, June 2020 Globally, prescribed fire, harvesting, and understory mastication, alone and in combination, are common forest management practices. Timber commodities, wildlife habitat, wildfire fuel reduction, soil conservation, and water quality are frequently targeted and assessed as these practices are util...
Article
Wildfire could alter both the quantity and composition of terrestrial organic matter exported into source water, and water treatability of fire-impacted dissolved organic matter (DOM) could be different from its unburned counterpart. Currently, there is no standard protocol to treat wildfire-impacted source water. To identify the best treatment pra...
Article
We investigated the effects of two California wildfires (Rocky and Wragg Fires, 2015) compared to an unburned reference watershed on water quality, dissolved organic matter (DOM), and precursors of disinfection by-products (DBPs) for two years' post-fire. The two burned watersheds both experienced wildfires but differed in the proportion of burned...
Article
Foliar litter is an important terrestrial source of dissolved organic matter (DOM) and disinfection byproducts (DBPs) in the source water supply. Climate changes could alter precipitation patterns and hydroperiods in woody wetlands, resulting in a hydrologic shift along the low elevation gradient and change the productions of DOC and DBP precursors...
Article
Torrential rain and extreme flooding caused by Atlantic hurricanes mobilize a large pool of organic matter (OM) from coastal forested watersheds in the southeastern United States. However, the mobilization of toxic metals such as mercury (Hg) that are associated with this vast pool of OM are rarely measured. This study aims to assess the variations...
Article
Full-text available
Disinfection processes might alter the chemical structure of biological recalcitrant natural organic matter (NOM) in source water to form assimilable organic carbon (AOC), which can be readily utilized by microbes for growth. However, AOC has not been classified as disinfection byproducts (DBPs) before and little is known about the chemical and str...
Article
The frequency of Atlantic hurricanes has been predicted to increase significantly by the end of this century. Watershed disturbance initiated by hurricanes can alter dissolved organic matter (DOM) quantity and quality in source water dramatically. DOM is an important disinfection by-product (DBP) precursor, and thus hurricanes can have a significan...
Article
Full-text available
More than half of the drinking water supply in the United States originates from forest watersheds, where terrestrial dissolved organic matter (DOM) is an important disinfection byproduct (DBP) precursor. Throughfall-derived DOM, a significant contributor of terrestrial DOM, has seldom been evaluated for its formation potential of DBPs. Here, we co...
Article
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Large, high-severity wildfires alter the physical and biological conditions that determine how catchments retain and release nutrients and regulate streamwater quality. The short-term water quality impacts of severe wildfire are often dramatic, but the longer-term responses may better reflect terrestrial and aquatic ecosystem recovery. We followed...
Article
Elevated levels of nutrients due to wildfire ash input into stream waters will likely cause algal blooms. When source water is impeded by algae and requires immediate restoration, copper algaecides are usually applied. Previous studies indicate that Cu ²⁺ can promote reactivity of dissolved organic matter in forming disinfection byproducts (DBPs)....
Article
Full-text available
Pyrogenic carbon (PyC) is an incomplete combustion by-product with longer soil residence times compared with nonpyrogenic components of the soil carbon (C) pool and can be preferentially eroded in fire-affected landscapes. To investigate geomorphic and fire-related controls on PyC erosion, sediment fences were established in three combinations of s...
Article
Full-text available
Watershed management practices such as prescribed fire, harvesting and understory mastication can alter the chemical composition and thickness of forest detritus, thus affecting the quantity and quality of riverine dissolved organic matter (DOM). Long-term effects of watershed management on DOM composition were examined through parallel field and e...
Article
Fires alter terrestrial dissolved organic carbon (DOC) exports into water, making reliable post-fire DOC monitoring a crucial aspect of safeguarding drinking water supply. We evaluated DOC optical sensors in a pair of prescribed burned and unburned first-order watersheds at the Santee Experimental Forest, in the coastal plain forests of South Carol...
Article
Watershed management practices such as prescribed fire, harvesting and understory mastication can alter the chemical composition and thickness of forest detritus, thus affecting the quantity and quality of riverine dissolved organic matter (DOM). Long-term effects of watershed management on DOM composition were examined through parallel field and e...
Cover Page
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The 2013 Rim Fire in California altered the landscape and generated a vast amount of polycyclic aromatic hydrocarbons in the ashes and soils. Photo credit: Jun-Jian Wang.
Article
Wildfires are expected to become more frequent and intensive at the global scale due to climate change. Many studies have focused on the loss of mercury (Hg) from burned forests; however, little is known about the origins, concentration, reactivity, and bioavailability of Hg in residual ash materials in postfire landscapes. We examine Hg levels and...
Article
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Recent studies suggest increased fire frequency may impair soil chemistry, but few studies have examined long-term effects of repeated, frequent prescribed fires on forest soil properties in the southeastern Coastal Plain, USA. In this study, forest soil chemistry at the 0-10 and 10-20 cm mineral soil depths of sandy surface horizons (Entisols and...
Article
Subaqueous wetland sediments (SWSs) and banana peels (BPs), respectively used as anaerobic inoculums and raw materials, were valorized for electricity generation in membrane-less and biocathode-containing microbial fuel cells (MLBC-MFCs). The maximum current density was 78.2 mA/m 2 for banana peel extracts (BPE) and 91.3 mA/m 2 for anaerobically fe...
Article
Full-text available
Wildfire-altered soil may be an important source of polycyclic aromatic hydrocarbons (PAHs) in the environment. With projected increase of wildfire frequency and intensity due to changing global climate, understanding the quantity and speciation of PAHs, including halogenated PAHs (XPAHs), resulting from different burn intensities has important ram...
Article
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Tropical and subtropical-storm surges combined with sea level rise cause saltwater intrusions into low-lying coastal ecosystems along the southeastern coast of the USA, gradually converting freshwater forested wetland into salt marsh. The transition zone between freshwater and saltwater ecosystems becomes a degraded forested wetland, where the comb...
Article
Carbon (C) standing stocks, C mass balance, and soil C burial in tidal freshwater forested wetlands (TFFW) and TFFW transitioning to low-salinity marshes along the upper estuary are not typically included in "blue carbon" accounting, but may represent a significant C sink. Results from two salinity transects along the tidal Waccamaw and Savannah ri...
Article
In recent years, the Chinese government has strengthened its efforts in surface water protection and restoration through strict policies and heavy investments. A clear understanding of the impacts of land use on water quality is necessary in order to ensure an effective and efficient implementation of the ongoing surface water restoration programin...
Article
Full-text available
Two intense rainfalls [Hurricane Joaquin (2015) and Hurricane Matthew (2016)], one year apart, provided a unique opportunity to examine changes in dissolved organic matter (DOM) dynamics in coastal blackwater rivers under extreme flooding conditions in the southeastern United States. Two sites along Waccamaw River (a coastal blackwater river) and t...
Article
To investigate the occurrence and distribution of microplastics in the southeastern coastal region of the United States, we quantified the amount of microplastics in sand samples from multiple coastal sites and developed a predictive model to understand the drift of plastics via ocean currents. Sand samples from eighteen National Park Service (NPS)...
Article
Forested wetlands dominated by baldcypress (Taxodium distichum) and water tupelo (Nyssa aquatica) are commonly found in coastal regions of the southeastern United States. Global climate change and in particular sea level rise will alter the frequency and magnitude of wet/dry periods and salinity levels in these ecosystems. Soil microcosm experiment...
Article
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The O horizon, or detrital layer, of forest soils is linked to long-term forest productivity and health. Fuel reduction techniques, such as prescribed fire, can alter the thickness and composition of this essential ecosystem component. Developing an understanding of the changes in the chemical composition of forest detritus due to prescribed fire i...
Article
Coastal blackwater rivers, characterized by high concentrations of natural organic matter, are source water for millions of people in the southeastern US. In October 2015, large areas of coastal South Carolina were flooded by Hurricane Joaquin. This so-called "thousand-year" rainfall mobilized and flushed large amounts of terrestrial organic matter...
Article
Full-text available
Wildfires can elevate dissolved organic matter (DOM) levels due to ash input and algal growth in source waters, and consequently impacting disinfection byproduct (DBP) formation in finished water; however, it remains unclear how quality and quantity of overall allochthonous and autochthonous DOM as well as associated DBP formation are changed durin...
Article
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L Large, high-severity wildfires alter the ecological processes that determine how watersheds retain and release nutrients and affect stream water quality. These changes usually abate a few years after a fire but recent studies indicate they may persist longer than previously expected. Wildfires are a natural disturbance agent, but due to the incre...
Article
Full-text available
Understanding the relationship between fire intensity and fuel mass is essential information for scientists and forest managers seeking to manage forests using prescribed fires. Peak burning temperature, duration of heating, and area under the temperature profile are fire behavior metrics obtained from thermocoupledatalogger assemblies used to char...
Article
The Rim Fire ignited on August 17, 2013 and became the third largest wildfire in California history. The fire consumed 104,131 ha of forested watersheds that were the drinking water source for 2.6 million residents in the San Francisco Bay area. To understand temporal variations in dissolved organic matter (DOM) after the wildfire and its potential...
Article
Previous studies demonstrated that wildfires alter spectroscopic characteristics of terrestrial dissolved organic matter (DOM) and increase specific disinfection byproduct formation potential (SDBP-FP). However, it is unclear whether characteristics of thermally-altered DOM (TA-DOM) are altered by biogeochemical processes (e.g., transformed by grow...
Article
Soil haloform emissions are sources of reactive halogens that catalytically deplete ozone in the stratosphere but there are still unknown or underestimated haloform sources. The >200 000 ha of low-lying tidal freshwater swamps (forests and marshes) in the south-eastern United States could be haloform (CHX3, X = Cl or Br) sources because sea-level r...
Article
Forest fires are occurring with increasing frequency and severity in the western USA potentially altering the chemistry and quantity of dissolved organic matter (DOM) and disinfection byproduct (DBP) precursors exported from forested watersheds. However, little is known concerning effects of the fire triangle (heat, oxygen, and fuel) on DOM alterat...
Chapter
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Controlling the disinfection by-product (DBP) formation, while balancing the risk of bacterial contamination in finished water, requires an in depth understanding in both the chemistry of DBPs and the kinetic and mechanism of bacterial disinfection. Although numerous studies have examined different strategies on the reduction of DBP formation in fi...
Article
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Based on a cross-national social survey, this paper ascertains how perception of climate change is related to national wealth and adaptive capacity across 33 countries. Results indicate that citizens of wealthier countries tend to see climate change as the most important problem, but are less likely to rank it as a highly dangerous threat. We find...
Article
Wildfire occurrence and intensity are increasing worldwide causing severe disturbances to forest watersheds used for potable water supply. The effects of wildfire on drinking water quality are not well understood, especially in terms of terrestrial dissolved organic matter (DOM) and DOM-associated formation of disinfection byproducts (DBP). As the...
Chapter
Full-text available
Detritus material in forested watersheds is the major terrestrial source of dissolved organic matter (DOM) and disinfection by-product (DBP) precursors in source waters. Forest fire reduces the thickness of detritus layer and changes foliar litters into pyrogenic organic matter (PyOM) on the forest floor, resulting in different quantity and quality...
Article
Fine roots constitute a significant source of plant productivity and litter turnover across terrestrial ecosystems, but less is known about the quantitative and qualitative profile of phenolic compounds within the fine root architecture, which could regulate the potential contribution of plant roots to soil organic matter pool. To understand the l...
Article
Microbial fuel cell (MFC) technology has shown great potential for harvesting energy from waste organic materials. Here, we explored the potential of MFC-based electricity generation from forest detritus, a large untapped biomass pool. Electricity generation from in situ MFCs and relevant environmental parameters (i.e., carbon sources and concentra...
Article
Small, shallow, seasonal wetlands with short hydroperiod (2-4 months) play an important role in the entrapment of organic matter and nutrients and, due to their wide distribution, in determining the water quality of watersheds. In order to explain the temporal, spatial and compositional variation of water quality of seasonal wetlands, we collected...
Article
Small, shallow, seasonal wetlands with short hydroperiod (2–4 months) play an important role in the entrapment of organic matter and nutrients and, due to their wide distribution, in determining the water quality of watersheds. In order to explain the temporal, spatial and compositional variation of water quality of seasonal wetlands, we collected...
Chapter
Forest detritus material is one of the major terrestrial sources of dissolved organic matter (DOM) in source waters. There is a health concern on DOM because it reacts with disinfectants to form a variety of potentially carcinogenic disinfection by-products (DBPs) during drinking water treatments. Prescribed fire is a common forest management pract...
Conference Paper
Full-text available
Fireflies are a unique part of the natural landscape at a global scale. Urban development and changes in the landscape can negatively affect firefly distribution and abundance. Assessment of firefly abundance through counts of bioluminescence flashes provides an environmental quality indicator that can be easily observed and quantified by citizen s...