Freshwater Wetland Ecosystems Research Articles

Spatial-temporal patterns of fish trophic guilds in a freshwater river wetland ecosystem of northeastern China.

Muling River, situated amidst cultivated lands in Heilongjiang Province, northeastern China, has long been subjected to sand-digging activities, resulting in severe damage to its riverbed. However, little research has been conducted on the impact of this disturbance on the status of fish community structure and trophic guilds in this river. In this study, environmental factors, fish community structure, and fish trophic guild biomass distribution patterns from the Muling River basin were investigated among seasons (spring, summer, and autumn) and sections (upper, middle, and lower stream) in 2015 and 2017. During the six sampling times periods, 46 species of five orders and 12 families of fish were classified into seven trophic guilds. Fish species number and biomass were higher upper reaches of the watershed. The insectivores (16.26%), phytoplanktivores (10.09%), benthivores (40.17%), and omnivores (11.86%) were the dominant trophic guilds. We found that fish trophic guilds biomass and environmental factors such as transparency, water depth, pH value, total phosphorus, and chemical oxygen demand were highest in the upper section compared to other sections. Variation partitioning revealed that fish trophic guilds biomass was influenced more by environmental factors (61.2%), followed by section (0.7%) and season (0.1%). Partial RDA ordination showed that fish trophic guilds were positively correlated with water depth and transparency, while negative with turbidity. This study underscores the importance of considering trophic guilds of freshwater fishes to inform management strategies in regions experiencing significant environmental change.

Can artificially induced habitat complexity alter macroinvertebrates diversity? A case study from a freshwater wetland ecosystem

Habitat complexity can enhance the resilience of wetlands against environmental stressors such as extreme weather events, pollution, and habitat loss. The introduction of artificial induced complexity (AIC) can play a significant role in reshaping the macroinvertebrate communities within wetland ecosystems by enhancing habitat quality in protected areas. Therefore, this study was designed to examine the variation of macroinvertebrates community structure in artificially induced complex sanctuary site (SS), partially protected (PP) and open sites (OS) from July 2019-April 2020. AIC in the sanctuary sites was established through the installation of cemented hexapods and ring pipes. Over the study period, a total of 665 macroinvertebrates were gathered, with 55.55% originating from SS, 31.14% from PP, and 18.21% from OS sites. The community consists mainly of Lymnaea acuminatatea and Tubifex tubifex, with the most abundant species being Limnodrillus hoffmeisteri and Branchiura sowerbyi. A notable positive impact of AIC was evident in the increased total abundance and diversity indices of macroinvertebrate communities. The Analysis of Similarity (ANOSIM) revealed significant distinctions in community structures among various intervention types, which was further corroborated by a non-metric multidimensional scaling (nMDS) plot. Similarity of Percentage Analysis (SIMPER) highlighted that Limnodrillus hoffmeisteri made the most significant contribution to the dissimilarity observed among the different intervention types. Canonical Correspondence Analysis (CCA) revealed a close association between the structure of the macroinvertebrate community and three key ecological factors: periphyton biomass, macrophyte cover, and sediment properties. These findings could offer a more effective approach for managers and policymakers engaged in the conservation of macroinvertebrates and the sustainable management of fisheries resources within wetland ecosystems.

Fate and biological uptake of polystyrene nanoparticles in freshwater wetland ecosystems

Wetland mesocosms retained nanoplastics. Nanoplastics where taken up by freshwater invertebrates and macrophytes and mainly ended up in the sediments of the water compartment.

Freshwater wetland–driven variation in sulfur isotope compositions: Implications for human paleodiet and ecological research

Sulfur isotope (δ34S) analyses are an important archaeological and ecological tool for understanding human and animal migration and diet, but δ34S can be difficult to interpret, particularly in archaeological human-mobility studies, when measured isotope compositions are strongly 34S-depleted relative to regional baselines. Sulfides, which accumulate under anoxic conditions and have distinctively low δ34S, are potentially key for understanding this but are often overlooked in studies of vertebrate δ34S. We analyze an ecologically wide range of archaeological taxa to build an interpretive framework for understanding the impact of sulfide-influenced δ34S on vertebrate consumers. Results provide the first demonstration that δ34S of higher-level consumers can be heavily impacted by freshwater wetland resource use. This source of δ34S variation is significant because it is linked to a globally distributed habitat and occurs at the bottom of the δ34S spectrum, which, for archaeologists, is primarily used for assessing human mobility. Our findings have significant implications for rethinking traditional interpretive frameworks of human mobility and diet, and for exploring the historical ecology of past freshwater wetland ecosystems. Given the tremendous importance of wetlands’ ecosystem services today, such insights on the structure and human dynamics of past wetlands could be valuable for guiding restoration work.

Variability of carbon stored in inland freshwater wetland in Northeast India

Inland freshwater wetland ecosystems are among the largest sink of carbon (C) in the biosphere. However, improved scientific understanding of the C stability and sequestration potential is required to predict response of C pool under environmental change and to identify priorities for lacustrine C sink management. This study analyses the concentration of organic C fractions based on their stability and estimates C stock along with depth and eco-zones of the Rudrasagar lake in Northeast India. Sediment samples up to 100 cm depth were collected from littoral, sub-littoral and deep layers, and analysed for organic C concentrations. Results showed that C concentration decreases with depth in the littoral layer but increases with depth in sub-littoral and deep layers. Two-way analysis of variance showed that concentrations of soil organic C (SOC) fractions were significantly different among the eco-zones but not between the soil depth. Average SOC stock was significantly higher in the deep layer (334.9 Mg C ha−1) followed by sub-littoral (248.4 Mg C ha−1) and littoral layer (106.1 Mg C ha−1). Overall, we show that substantial spatial variability in SOC stock exists among the eco-zones and depth that may be driven by water inundation in deep layer and fluctuating hydrological conditions at the edges of the lacustrine ecosystem. Our study demonstrates that inland freshwater wetland is a major sink of organic C and if disturbed it can act as a carbon dioxide source.

Modelling hydrological strength and alteration in moribund deltaic India.

The Ganga-Brahmaputra moribund deltaic floodplain region hosted many socio-ecologically precious freshwater wetland ecosystems experiencing hydrological alteration. The present study aimed to model hydrological strength (HS) to show the spatial difference and account for the degree and direction of hydrological alteration of Indian moribund deltaic wetland in three phases e.g. (1) phase I (1988-1997), (2) phase II (1998-2007) and phase III (2008-2017). Three key hydrological parameters, such as Water Presence Frequency (WPF), water depth, and hydro-period were considered for hydrological strength modelling using two ensemble Machine Learning (ML) techniques (Random Forest (RF) and XGBoost). Image algebra was employed for phasal change detection. Hydrological strength models show that around 75% of the wetland area was lost in-between phases I to III and the loss was found more intensive in moderate and weak HS zones. Existing wetland shows a clear spatial difference of HS between wetland core and periphery and river linked and delinked or not linked wetlands. Regarding the suitability of the ML models, both are acceptable, however, the XGBoost outperformed in reference to applied 15 statistical validation techniques and field evidence. HS models based on change detection clarified that more than 22% and 55% of the weak HS zone in phases II and III respectively were turned into non-wetland. The degree of alteration revealed that about 40% of wetland areas experienced a negative alteration during phases I to II, and this proportion increased to 63% in between phases II to III. Since the study figured out the spatial nature of HS, degree and direction of alteration at a spatial scale, these findings would be instrumental for adopting rational planning towards wetland conservation and restoration.

Seasonal variations in physicochemistry of water and sediment of a degraded freshwater wetland ecosystem: a case study of Ipare wetland in Ondo State, Nigeria

This study was carried out to investigate the seasonal variations (dry and rainy seasons) in physicochemical characteristics of a degraded freshwater wetland in Ipare, Ondo State. The physicochemical parameters of water and sediment samples from three degraded stations and a control (non-degraded site) were analysed using standard analytical method. Results showed that sodium and chloride concentrations in water ranged from 1329 to 1583 mg/l and 7373.9 to 9345.5 mg/l (dry season), and 56.87 to 207.06 mg/l and 130.4 to 513.76 mg/l (rainy season), respectively. The sediment showed sodium and chloride concentrations that ranged from 738.08 to 742.33 mg/kg and 1749.69 to 1793.94 mg/kg (dry season), and 410.25 to 411.93 mg/kg and 702.82 to 848.09 mg/kg (rainy season), respectively. Values for the control for sodium were 29.59 mg/l and 58.62 mg/kg (dry season) and 7.11mg/l and 9.6 mg/kg (wet season), while chloride values were 61.2 mg/l and 126.56 mg/kg (dry season) and 15.81 mg/l and 17.52 mg/l (rainy season) for water and sediment, respectively. All other physicochemical parameters were altered due to the variation in season. Statistical analysis showed a significant difference (p< 0.05) between the degraded sites and the control. The study showed that season and anthropogenic activities have significant effects on the physicochemical characteristics of sediment and water in the freshwater wetland and, therefore, contribute to wetland degradation.

A Review on Wetlands – Threats, Conservation, Strategies and Policies

Globally 64% of the wetlands have disappeared since 1970 and the loss is higher in Asia, about 5000 km2 annually due to agriculture, dam construction and other uses. In India, the loss is about 38% with the disappearance rate of 2-3% per year. Further dependence on these wetlands leads to either extinction or threatened the species including 21% of bird species, 37% of mammal species and 20% fresh water fish species. Wetlands are lands transitional between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water level. According to Ramsar convention the wetlands are classified as three types via., coastal/ marine wetlands, inland wetlands and human made wetlands. Worldwide, the freshwater wetland ecosystems are among the mostly heavily used, depended upon and exploited ecosystems for sustainability and well-being. The main causes of wetland loss have been classified into two types namely acute and chronic wetland loss. This loss in wetland area results in adverse impact on the key functions performed by wetlands. Hence, we have to conserve these wetlands by implementing effective legal framework and management strategies. In this context Ramsar convention is an important International Treaty for the Conservation and Sustainable use of Wetlands which was signed at a city of Iran (Ramsar) in 1971. There are currently over 2,400 Ramsar sites on the territories of 171 Ramsar Contracting Parties across the world. They cover over 2.5 million square kilometers, an area larger than Mexico.

Macrophyte diversity and their uses with special reference to freshwater wetland ecosystem Barbilabeel of Nalbari district, Assam, India

Macrophyte diversity and their uses with special reference to freshwater wetland ecosystem Barbilabeel of Nalbari district, Assam, India

Development of a Novel Fuzzy Logic-Based Wetland Health Assessment Approach for the Management of Freshwater Wetland Ecosystems

Development of a Novel Fuzzy Logic-Based Wetland Health Assessment Approach for the Management of Freshwater Wetland Ecosystems

Land-Use and Land-Cover Change Detection in a North-Eastern Wetland Ecosystem of Bangladesh Using Remote Sensing and GIS Techniques

Lakshmibaur-Nalair Haor, a freshwater wetland ecosystem is situated in the north-eastern region of Bangladesh. This place hosts the second largest freshwater swamp forest in Bangladesh. Containing rich biodiversity, this unique area experiences significant landscape changes. This study examines land-use and land-cover (LULC) changes between 1989 and 2019 in the Lakshmibaur-Nalair Haor area by operating Landsat multispectral imageries through remote sensing (RS) and geographic information system (GIS) techniques. The changing status of the haor was analyzed by initiating normalized difference vegetation index (NDVI) and modified normalized difference water index (MNDWI). The unsupervised classification technique was implemented to classify these images into five major classes (vegetation, cropland, bare soil, shallow water, and deep water bodies) using threshold values of NDVI and MNDWI. After accuracy assessment, the post-classification comparison method was performed to evaluate the change detection. This study demonstrates that this valuable area lost ~ 2208.6 ha (37.54%) of the deep water body and 489.6 ha (8.34%) of vegetation over the last 3 decades. However, it has gained about 1729 ha (29.39%) of cropland, 2673 ha (45.44%) of shallow water and 1124 ha (28%) of bare soil. Such changes indicate significant human interventions such as expansion of croplands with increased population pressure. Gradual change of deep water into shallow water over time is enabling local community to expand agricultural lands and activities during the dry season. This study’s findings are useful in understanding and tracking changes in wetlands in Bangladesh and other similar settings.

Effects of Land Use and Pollution Loadings on Ecotoxicological Assays and Bacterial Taxonomical Diversity in Constructed Wetlands

Freshwater ecosystems are affected by anthropogenic alterations. Different studies have extensively studied the concentrations of metals, nutrients, and water quality as measurements of pollution in freshwater ecosystems. However, few studies have been able to link these pollutants to bioindicators as a risk assessment tool. This study aimed to examine the potential of two bioindicators, plant ecotoxicological assays and sediment bacterial taxonomic diversity, in ecological risk assessment for six freshwater constructed wetlands in a rapidly urbanizing watershed with diverse land uses. Sediment samples were collected summer, 2015 and 2017, and late summer and early fall in 2016 to conduct plant ecotoxicological assays based on plant (Lepidium, Sinapis and Sorghum) growth inhibition and identify bacterial taxonomical diversity by the 16S rRNA gene sequences. Concentrations of metals such as lead (Pb) and mercury (Hg) (using XRF), and nutrients such as nitrate and phosphate (using HACH DR 2800TM spectrophotometer) were measured in sediment and water samples respectively. Analyses of response patterns revealed that plant and bacterial bioindicators were highly responsive to variation in the concentrations of these pollutants. Hence, this opens up the scope of using these bioindicators for ecological risk assessment in constructed freshwater wetland ecosystems within urbanizing watersheds.

Intermittent hydrologic perturbations control solute cycling and export in the Okavango Delta

We measured the concentrations of the total dissolved ions (TDI), dissolved silica, major cations and the δD and δ18O at sub-weekly intervals for one year in the Okavango River at the outlet of the Okavango Delta (Delta). Our objectives were to (1) document the temporal variations in the concentrations of solutes in the Okavango River, (2) determine the processes controlling the transfer of solutes to the river and (3) assess the temporal solute load and outflux from the Delta. We found that the TDI and major cation concentrations in the river were anomalously high during the rainy season and before the arrival of the annual flood pulse. The anomalous increases in the solute concentrations are due to dissolution and mobilization of precipitated salts stored in the floodplains and on hundreds of thousands of islands scattered across the Delta wetlands, as well as from ‘flushing’ of remnant evaporated flood water of higher salinity trapped in isolated wetland pools. Overland flow generated by local rains and flooding connect the river to the solute stores in the watershed. The temporally activated hydrologic flow pathways transfer solutes to the river that flushes them out of the Delta. The solute load in the river was higher during the rainy season and during pulse flooding, and mimicked the discharge hydrograph. We estimate that 17,838 Mg/y of dissolved solutes was flushed out of the Delta, with 67% removed during pulse flooding (6 months) and 30% during the rainy season (4 months). The transfer of solutes from the watershed to the river during pulse flooding and the rainy season, and solute export from the Delta is an important mechanism that keeps the Delta’s surface water resources fresh, which is critical for supporting a freshwater wetland ecosystem. Our results highlight the importance of intermittent activation of hydrologic flow pathways in controlling solute cycling in this and other arid watersheds.

Typhoon-induced increases in porewater nutrient concentrations and CO2 and CH4 emissions associated with salinity and carbon intrusion in a subtropical tidal wetland in China: A mesocosm study

Typhoons can alter carbon cycling by increasing carbon inputs and by the oceanic water intrusion at low latitudes. Our understanding of how typhoons impacts C and N cycles by reflecting combine and separate effects of elevated salinity and carbon enrichment is poor. We conducted a mesocosm experiment simulating the effect of a salinity of 10‰ and dissolved organic carbon (DOC) enrichment of the surface water with acetate as DOC source on the dynamics of porewater nutrients and the emissions of carbonaceous greenhouse gases using plants and soil system from a Cyperus malaccensis freshwater wetland in the Min River estuary, southeastern China. The concentrations of NH4+-N and NO3−-N in porewater rose under elevated salinity but decreased with DOC enrichment, salinity and DOC in combination acted antagonistically such that there was no effect compared to the control. A 10‰ increase in salinity increased the cumulative CO2 emissions (+29%) and decreased the cumulative CH4 emissions (−61%) during the growing season. In response to DOC, The cumulative emissions of CO2 and CH4 increased by 79% and 84%, respectively. In response to the combined elevated salinity and DOC enrichment, the cumulative emissions of CO2 increased by 69% and cumulative methane emissions increased by 44%. Elevated salinity plus DOC enrichment decreased the activity of the N-cycling enzyme β-1,4-N-acetylglucosaminidase, but increased the activities of two C-cycling enzymes (β-1,4-glucosidase and 1,4-β-cellobiosidase) and the P-cycling enzyme acid phosphatase, indicating a higher demand for C and P relative to N. The combination of increased C as CO2 in all cases, increased CH4 only in the case of DOC addition, and rising inorganic N fluxes only in the case of salt suggeated that elevated salinity and DOC enrichment induced by typhoons may thus accelerate the release of C but have little influence on N release from tidal freshwater wetland ecosystems.

Foliar water uptake of fog confers ecophysiological benefits to four common tree species of southeastern freshwater forested wetlands

AbstractFog, dew and cloud‐borne mist are sources of water to vegetation in many ecosystems. The importance of fog as a water source has been documented well beyond ecosystems where plants experience fog for extensive periods over the course of the day (e.g. cloud forests); however, relatively little is known regarding the roles of fog and foliar water uptake in ecosystems such as coastal freshwater wetlands that do not experience fog for extensive periods over the course of the day. Coastal freshwater wetland ecosystems lie on the forefront of climate change‐associated stressors that threaten freshwater supplies to vegetation. Considering the potential impact of climate warming on diminishing coastal fog regimes, an improved understanding of the ecophysiological benefits of fog immersion to the vegetation in these ecosystems is critical for understanding the response of these ecosystems to global climate change. Herein, we investigate the potential for foliar water deposition from fog to act as a direct freshwater subsidy to four tree species (Taxodium distichum (L.) Rich., Nyssa aquatica L., Nyssa biflora Walter and Liquidambar styraciflua L.) that are common in coastal freshwater wetlands. All four species showed the capacity for foliar water uptake across the leaf/needle surface, with a ca. 5–10% increase in leaf water content after a 3‐h submersion experiment. Stable isotopes of water provided strong evidence for foliar water uptake in all four species and for bark water uptake in T. distichum after a 24‐h fogging experiment. Fog exposure also resulted in several ecophysiological benefits to the saplings, including significant improvements in pre‐dawn water status and net photosynthesis.

Implication of Viral Infections for Greenhouse Gas Dynamics in Freshwater Wetlands: Challenges and Perspectives.

Viruses are non-living, acellular entities, and the most abundant biological agents on earth. They are widely acknowledged as having the capacity to influence global biogeochemical cycles by infecting the bacterial and archaeal populations that regulate carbon and nutrient turnover. Evidence suggests that the majority of viruses in wetlands are bacteriophages, but despite their importance, studies on how viruses control the prokaryotic community and the concomitant impacts on ecosystem function (such as carbon cycling and greenhouse gas flux) in wetlands are rare. Here we investigate virus-prokaryote interactions in freshwater wetland ecosystems in the context of their potential influence on biogeochemical cycling. Specifically, we (1) synthesize existing literature to establish current understanding of virus-prokaryote interactions, focusing on the implications for wetland greenhouse gas dynamics and (2) identify future research priorities. Viral dynamics in freshwater wetlands have received much less attention compared to those in marine ecosystems. However, based on our literature review, within the last 10 years, viral ecology studies on freshwater wetlands have increased twofold. Despite this increase in literature, the potential implication of viral infections on greenhouse gas emission dynamics is still a knowledge gap. We hypothesize that the rate of greenhouse gas emissions and the pool of sequestered carbon could be strongly linked to the type and rate of viral infection. Viral replication mechanism choice will consequently influence the microbial efficiency of organic matter assimilation and thus the ultimate fate of carbon as a greenhouse gas or stored in soils.

Phosphorus alleviation of salinity stress: effects of saltwater intrusion on an Everglades freshwater peat marsh.

Saltwater intrusion and salinization of coastal wetlands around the world are becoming a pressing issue due to sea level rise. Here, we assessed how a freshwater coastal wetland ecosystem responds to saltwater intrusion. In wetland mesocosms, we continuously exposed Cladium jamaicense Crantz (sawgrass) plants and their peat soil collected from a freshwater marsh to two factors associated with saltwater intrusion in karstic ecosystems: elevated loading of salinity and phosphorus (P) inputs. We took repeated measures using a 2 × 2 factorial experimental design (n=6) with treatments composed of elevated salinity (~9ppt), P loading (14.66μmol P/d), or a combination of both. We measured changes in water physicochemistry, ecosystem productivity, and plant biomass change over two years to assess monthly and two-year responses to saltwater intrusion. In the short-term, plants exhibited positive growth responses with simulated saltwater intrusion (salinity + P), driven by increased P availability. Despite relatively high salinity levels for a freshwater marsh (~9 ppt), gross ecosystem productivity (GEP), net ecosystem productivity (NEP), and aboveground biomass were significantly higher in the elevated salinity + P treated monoliths compared to the freshwater controls. Salinity stress became evident after extended exposure. Although still higher than freshwater controls, GEP and NEP were significantly lower in the elevated salinity + P treatment than the +P treatment after two years. However, elevated salinity decreased live root biomass regardless of whether P was added. Our results suggest that saltwater intrusion into karstic freshwater wetlands may initially act as a subsidy by stimulating aboveground primary productivity of marsh plants. However, chronic exposure to elevated salinity results in plant stress, negatively impacting belowground peat soil structure and stability through a reduction in plant roots.

Mobile Colloidal Organic Carbon: An Underestimated Carbon Pool in Global Carbon Cycles?

Mobile colloids, 1-1000 nm particles, are ubiquitous in every ecosystem. They have small size, large specific surface area and high mobility in the subsurface, and thus can regulate the fate and transport of sorbing constituents such as nutrients, contaminants and organic carbon (OC). The movement of colloids and colloidal OC (COC) through soils is an important process in mass and energy transport (including carbon) both within and between ecosystems, e.g. from terrestrial to aquatic ecosystems, and likely contribute to the ecosystem- or global-scale carbon balance given their ubiquitous distribution and unique environmental functions. However, despite their importance for terrestrial and aquatic carbon transport and balance, colloids and COC have not been adequately accounted for because of the current operational definition uses 0.45 µm as the cutoff size for colloids. In this study, we quantified and characterized loadings of colloids and COC in aqueous samples collected from agricultural, forestry, freshwater wetland and estuary ecosystems. Results reveal that, in all samples regardless of the different sampling sources, the total colloidal loads were underestimated by ≥ 50% and considered as “dissolved” solutes when the operational definition (e.g., using a cutoff size of 0.45 m) was used. Together with a large number of data from the literature, our results further demonstrate that colloids are quantitatively substantial, carbon-dense and that as much as 8-19% of operationally defined DOC is in fact COC. Conservatively, this suggests that the COC pool potentially accounts for 13.6 TgC year-1 as a riverine flux and 530 ± 25 TgC of global DOC pool in the ocean in global carbon cycles. In addition, freshwater wetland was found to be a hotspot, which released more colloids and COC compared to the other sampled ecosystems. These findings clearly demonstrate the limitations of using the current operational definition for colloids and DOM and highlight the need for improving quantification and characterization of size-dependent colloidal and OC loads. Such effort will allow direct fundamental research into questions towards microbial access to ‘protected’ carbon by minerals and more accurate assessment of global carbon cycles.

Microbial subnetworks related to short-term diel O2 fluxes within geochemically distinct freshwater wetlands.

Oxygen (O2) concentrations often fluctuate over diel timescales within wetlands, driven by temperature, sunlight, photosynthesis and respiration. These daily fluxes have been shown to impact biogeochemical transformations (e.g. denitrification), which are mediated by the residing microbial community. However, little is known about how resident microbial communities respond to diel physical and chemical fluxes in freshwater wetland ecosystems. In this study, total microbial (bacterial and archaeal) community structure was significantly related to diel time points in just one out of four distinct freshwater wetlands sampled. This suggests that daily environmental shifts may influence wetlands differentially based upon the resident microbial community and specific physical and chemical conditions of a freshwater wetland. When exploring the microbial communities within each wetland at finer resolutions, subcommunities of taxa within two wetlands were found to correspond to fluctuating O2 levels. Microbial taxa that were found to be susceptible to fluctuating O2 levels within these subnetworks may have intimate ties to metabolism and/or diel redox cycles. This study highlights that freshwater wetland microbial communities are often stable in community structure when confronted with short-term O2 fluxes; however, specialist taxa may be sensitive to these same fluxes.

Water Source Utilization in Taxodium distichum (L.) Rich. (baldcypress) over the Course of a Growing Season in a Restored Coastal Freshwater Wetland Vulnerable to Saltwater Incursion

ABSTRACT Stable isotopic analysis of water use patterns in wetland vegetation can provide insight into the anticipated ecophysiological response of individual species to seasonal and/or episodic changes in water quality such as saltwater incursion into freshwater wetland ecosystems. In this study, variation in water source utilization over the course of a growing season was investigated in Taxodium distichum (baldcypress), a foundational species in both naturally occurring wetlands and regional wetland restoration projects in the southeastern United States. Over the course of the 2014 growing season, water use patterns were monitored in three baldcypress stands at the Timberlake Observatory for Wetland Restoration (TOWeR) in Tyrrell County, North Carolina, by comparing the isotopic composition (δ2H and δ18O) of xylem water extracted from plant tissue to that of the available water sources: surface water, sediment porewater, groundwater sampled from multiple locations in the region, and rainwater. Results...