Journal articles on the topic 'Seasonal freshwater wetland'
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Schoepfer, Valerie, Amy Burgin, Terry Loecke, and Ashley Helton. "Seasonal Salinization Decreases Spatial Heterogeneity of Sulfate Reducing Activity." Soil Systems 3, no. 2 (April 2, 2019): 25. http://dx.doi.org/10.3390/soilsystems3020025.
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Evidence of sulfate input and reduction in coastal freshwater wetlands is often visible in the black iron monosulfide (FeS) complexes that form in iron rich reducing sediments. Using a modified Indicator of Reduction in Soils (IRIS) method, digital imaging, and geostatistics, we examine controls on the spatial properties of FeS in a coastal wetland fresh-to-brackish transition zone over a multi-month, drought-induced saltwater incursion event. PVC sheets (10 × 15 cm) were painted with an iron oxide paint and incubated vertically belowground and flush with the surface for 24 h along a salt-influenced to freshwater wetland transect in coastal North Carolina, USA. Along with collection of complementary water and soil chemistry data, the size and location of the FeS compounds on the plate were photographed and geostatistical techniques were employed to characterize FeS formation on the square cm scale. Herein, we describe how the saltwater incursion front is associated with increased sulfate loading and decreased aqueous Fe(II) content. This accompanies an increased number of individual FeS complexes that were more uniformly distributed as reflected in a lower Magnitude of Spatial Heterogeneity at all sites except furthest downstream. Future work should focus on streamlining the plate analysis procedure as well as developing a more robust statistical based approach to determine sulfide concentration.
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Jeffrey, Luke C., Damien T. Maher, Scott G. Johnston, Kylie Maguire, Andrew D. L. Steven, and Douglas R. Tait. "Rhizosphere to the atmosphere: contrasting methane pathways, fluxes, and geochemical drivers across the terrestrial–aquatic wetland boundary." Biogeosciences 16, no. 8 (April 29, 2019): 1799–815. http://dx.doi.org/10.5194/bg-16-1799-2019.
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Abstract. Although wetlands represent the largest natural source of atmospheric CH4, large uncertainties remain regarding the global wetland CH4 flux. Wetland hydrological oscillations contribute to this uncertainty, dramatically altering wetland area, water table height, soil redox potentials, and CH4 emissions. This study compares both terrestrial and aquatic CH4 fluxes in permanent and seasonal remediated freshwater wetlands in subtropical Australia over two field campaigns, representing differing hydrological and climatic conditions. We account for aquatic CH4 diffusion and ebullition rates and plant-mediated CH4 fluxes from three distinct vegetation communities, thereby examining diel and intra-habitat variability. CH4 emission rates were related to underlying sediment geochemistry. For example, distinct negative relationships between CH4 fluxes and both Fe(III) and SO42- were observed. Where sediment Fe(III) and SO42- were depleted, distinct positive trends occurred between CH4 emissions and Fe(II) ∕ acid volatile sulfur (AVS). Significantly higher CH4 emissions (p < 0.01) in the seasonal wetland were measured during flooded conditions and always during daylight hours, which is consistent with soil redox potential and temperature being important co-drivers of CH4 flux. The highest CH4 fluxes were consistently emitted from the permanent wetland (1.5 to 10.5 mmol m−2 d−1), followed by the Phragmites australis community within the seasonal wetland (0.8 to 2.3 mmol m−2 d−1), whilst the lowest CH4 fluxes came from a region of forested Juncus spp. (−0.01 to 0.1 mmol m−2 d−1), which also corresponded to the highest sedimentary Fe(III) and SO42-. We suggest that wetland remediation strategies should consider geochemical profiles to help to mitigate excessive and unwanted methane emissions, especially during early system remediation periods.
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Pfeifer-Meister, Laurel, Laura G. Gayton, Bitty A. Roy, Bart R. Johnson, and Scott D. Bridgham. "Greenhouse gas emissions limited by low nitrogen and carbon availability in natural, restored, and agricultural Oregon seasonal wetlands." PeerJ 6 (August 28, 2018): e5465. http://dx.doi.org/10.7717/peerj.5465.
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Wetlands are the major natural source of the greenhouse gas methane (CH4) and are also potentially an important source of nitrous oxide (N2O), though there is considerable variability among wetland types with some of the greatest uncertainty in freshwater mineral-soil wetlands. In particular, trace gas emissions from seasonal wetlands have been very poorly studied. We measured fluxes of CH4, N2O, and CO2(carbon dioxide), soil nutrients, and net primary productivity over one year in natural, restored, and agricultural seasonal wetland prairies in the Willamette Valley, Oregon, USA. We found zero fluxes for CH4and N2O, even during periods of extended waterlogging of the soil. To explore this lack of emissions, we performed a laboratory experiment to examine the controls over these gases. In a fully-factorial design, we amended anaerobic soils from all wetlands with nitrate, glucose, and NaOH (to neutralize pH) and measured production potentials of N2, N2O, CH4, and CO2. We found that denitrification and N2O production were co-limited by nitrate and carbon, with little difference between the three wetland types. This co-limitation suggests that low soil carbon availability will continue to constrain N2O emissions and denitrification in these systems even when receiving relatively high levels of nitrogen inputs. Contrary to the results for N2O, the amended wetland soils never produced significant amounts of CH4under any treatment. We hypothesize that high concentrations of alternative electron acceptors exist in these soils so that methanogens are noncompetitive with other microbial groups. As a result, these wetlands do not appear to be a significant source or sink of soil carbon and thus have a near zero climate forcing effect. Future research should focus on determining if this is a generalizable result in other seasonal wetlands.
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You, Hailin, Hongxiang Fan, Ligang Xu, Yongming Wu, Lizhen Liu, and Zhong Yao. "Poyang Lake Wetland Ecosystem Health Assessment of Using the Wetland Landscape Classification Characteristics." Water 11, no. 4 (April 19, 2019): 825. http://dx.doi.org/10.3390/w11040825.
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Currently, wetland stability is under threat due to the joint effects of global climate change and human activity, especially in lakes. Hence, it is necessary to evaluate the health status of wetland ecosystems such as lakes, identify the variables causing the wetland degradation and work to protect the wetlands from the identified variables in the future. Based on fourteen high-resolution autumn remote sensing images from 1989–2013, the classification characteristics and spatial distribution patterns of wetland landscapes in Poyang Lake were studied through quantitative interpretation technology. An established health assessment index system named the EHCI (Ecological Health Comprehensive Index) was used to assess the health status of Poyang Lake. Additionally, the relationship between water regime and health status of wetland landscape distribution of Poyang Lake were investigated by multivariate statistical analysis. The results demonstrated: (1) The total area of three first level (or six second level) types of wetland landscapes showed a stable status, which was long-term maintaining at about 3026 km2 from 1989–2013. (2) The water area shows a downward trend, while the areas of vegetation and land-water transition zone show upward trends. (3) The proposed EHCI of the Poyang Lake wetland presented a downward trend. According to the EHCI results from 1989–2013, the health status of Poyang Lake wetland was healthy for two years, unhealthy for four years and sub-healthy for eight years. (4) The water level fluctuation greatly affected the EHCI, and the effect became greater as the water level increased. These results contribute to the understanding of specific effects of hydrological process on the health status of the Poyang Lake wetland. In addition they provide a scientific reference for the maintenance of stable ecosystem functions of the seasonal freshwater lake. These results contribute to the understanding of specific effects of hydrological process on the health status of the Poyang Lake. In addition they provide a scientific reference for the maintenance of stable ecosystem functions of the seasonal freshwater lake.
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Mazur, I. "Identification conformity of wetlands biotopes of the Northwest of the Black Sea region." Agroecological journal, no. 3 (September 30, 2016): 153–59. http://dx.doi.org/10.33730/2077-4893.3.2016.249071.
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This publication presents the analysis of the mostly used international and Ukrainian classification systems for wetland areas performed for identification of different-type marsh biotopes of steppe rivers in the Northwest Black Sea Region. Among the classification systems, the most well-known are the Ramsar Classification System for Wetland Type (1971) and Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al., 1979). In these systems, valley marsh biotopes are identified as riverine and palustrine, non-tidal, unstable (perennial impounded and seasonal/intermittent) freshwater marshes on mineral rich soils predominantly covered by grasslike plants (rush, reedmace, sedge). The delta marshes of the Danube, Dniester and Dnieper are referred to as tidal brackish and freshwater marshes. According to Ukrainian classification systems for hygromorphic geosystem, marsh biotopes are regarded as mouth wetlands, which is peculiar to delta marsh areas of the Danube and Dnieper interfluve. Thus, riverbed marshes of small and medium-sized rivers are located in other areas and are usually met both in the lower (continuous marsh areas), middle (fragmented marsh mosaic), and upper (coastland) river flow areas, which is caused by an unstable watercourse rate and transforming of their riverbed parts into marsh sections covered by eurytopic wetland species.
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Grubh, Archis R., and Kirk O. Winemiller. "Spatiotemporal variation in wetland fish assemblages in the Western Ghats region of India." Knowledge & Management of Aquatic Ecosystems, no. 419 (2018): 35. http://dx.doi.org/10.1051/kmae/2018023.
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The Western Ghats region of peninsular India contains high diversity of freshwater fishes that support artisanal fisheries, but no studies to date have investigated fish assemblages of the region's extensive wetlands. This study examined fish population densities and the structure of local species assemblages in pools of the Periyakulam wetland of the Western Ghats. From 2000 to 2001, fishes and local abiotic environmental parameters were surveyed during three periods with contrasting rainfall (dry, major wet, minor wet). We hypothesized that fish density would be higher during the dry season when aquatic habitat is reduced, and that local assemblage structure would be strongly associated with habitat conditions. Total fish densities were higher during the dry season, but the magnitude of seasonal change was relatively low, and this apparently was because changes in water depth were minimal due to operation of sluice gates that control wetland hydrology. Chanda nama, Pseudetroplus maculatus, Rasbora daniconius, and Danio aequipinnatus were dominant species in most habitats during all three seasons. Multivariate ordinations revealed strong associations between assemblage structure and habitats based on vegetation cover. Local assemblages in shallow-vegetated habitats varied seasonally in association with gradients of rainfall and water quality parameters. Spatial variation of local fish assemblages in the Periyakulam wetland appears to be maintained by species-specific habitat selection. Although hydrologic regulation probably has reduced seasonal variation in the structure of local assemblages, seasonal differences still occur and appear to be caused by species differences with regard to periods of reproduction, recruitment, dispersal and habitat selection.
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Roy Chowdhury, Taniya, William J. Mitsch, and Richard P. Dick. "Seasonal methanotrophy across a hydrological gradient in a freshwater wetland." Ecological Engineering 72 (November 2014): 116–24. http://dx.doi.org/10.1016/j.ecoleng.2014.08.015.
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Delwiche, Kyle B., Sara Helen Knox, Avni Malhotra, Etienne Fluet-Chouinard, Gavin McNicol, Sarah Feron, Zutao Ouyang, et al. "FLUXNET-CH<sub>4</sub>: a global, multi-ecosystem dataset and analysis of methane seasonality from freshwater wetlands." Earth System Science Data 13, no. 7 (July 29, 2021): 3607–89. http://dx.doi.org/10.5194/essd-13-3607-2021.
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Abstract. Methane (CH4) emissions from natural landscapes constitute roughly half of global CH4 contributions to the atmosphere, yet large uncertainties remain in the absolute magnitude and the seasonality of emission quantities and drivers. Eddy covariance (EC) measurements of CH4 flux are ideal for constraining ecosystem-scale CH4 emissions due to quasi-continuous and high-temporal-resolution CH4 flux measurements, coincident carbon dioxide, water, and energy flux measurements, lack of ecosystem disturbance, and increased availability of datasets over the last decade. Here, we (1) describe the newly published dataset, FLUXNET-CH4 Version 1.0, the first open-source global dataset of CH4 EC measurements (available at https://fluxnet.org/data/fluxnet-ch4-community-product/, last access: 7 April 2021). FLUXNET-CH4 includes half-hourly and daily gap-filled and non-gap-filled aggregated CH4 fluxes and meteorological data from 79 sites globally: 42 freshwater wetlands, 6 brackish and saline wetlands, 7 formerly drained ecosystems, 7 rice paddy sites, 2 lakes, and 15 uplands. Then, we (2) evaluate FLUXNET-CH4 representativeness for freshwater wetland coverage globally because the majority of sites in FLUXNET-CH4 Version 1.0 are freshwater wetlands which are a substantial source of total atmospheric CH4 emissions; and (3) we provide the first global estimates of the seasonal variability and seasonality predictors of freshwater wetland CH4 fluxes. Our representativeness analysis suggests that the freshwater wetland sites in the dataset cover global wetland bioclimatic attributes (encompassing energy, moisture, and vegetation-related parameters) in arctic, boreal, and temperate regions but only sparsely cover humid tropical regions. Seasonality metrics of wetland CH4 emissions vary considerably across latitudinal bands. In freshwater wetlands (except those between 20∘ S to 20∘ N) the spring onset of elevated CH4 emissions starts 3 d earlier, and the CH4 emission season lasts 4 d longer, for each degree Celsius increase in mean annual air temperature. On average, the spring onset of increasing CH4 emissions lags behind soil warming by 1 month, with very few sites experiencing increased CH4 emissions prior to the onset of soil warming. In contrast, roughly half of these sites experience the spring onset of rising CH4 emissions prior to the spring increase in gross primary productivity (GPP). The timing of peak summer CH4 emissions does not correlate with the timing for either peak summer temperature or peak GPP. Our results provide seasonality parameters for CH4 modeling and highlight seasonality metrics that cannot be predicted by temperature or GPP (i.e., seasonality of CH4 peak). FLUXNET-CH4 is a powerful new resource for diagnosing and understanding the role of terrestrial ecosystems and climate drivers in the global CH4 cycle, and future additions of sites in tropical ecosystems and site years of data collection will provide added value to this database. All seasonality parameters are available at https://doi.org/10.5281/zenodo.4672601 (Delwiche et al., 2021). Additionally, raw FLUXNET-CH4 data used to extract seasonality parameters can be downloaded from https://fluxnet.org/data/fluxnet-ch4-community-product/ (last access: 7 April 2021), and a complete list of the 79 individual site data DOIs is provided in Table 2 of this paper.
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Gokula, V., and P. Ananth Raj. "Vaduvur and Sitheri lakes, Tamil Nadu, India: conservation and management perspective." Journal of Threatened Taxa 13, no. 6 (May 28, 2021): 18497–507. http://dx.doi.org/10.11609/jott.5547.13.6.18497-18507.
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Wetlands are declining globally. Hence, it is reasonable to assume that most existing wetlands are impacted to some degree by human land-use that in turn caused population declines in many wetland-dependent taxa. The National Wetland Atlas has classified Tamil Nadu as a wetland-rich state as they occupy 6.92% of geographic area. However, studies on wetlands are limited in Tamil Nadu. Hence, an attempt was made to identify the threats to the Vaduvur and Sitheri lakes and their associated fauna. In total, 118 species of birds belonging to 87 genera, 48 families and 18 orders in Vaduvur Lake and 87 species of birds belonging to 71 genera, 48 families and 16 orders in Sitheri Lake were recorded. A total of 28 zooplankton species were recorded in both the lakes comprising 14 species of rotifers, six species of cladocerans, five species of copepods, two species of ostracods, and one species of protozoa. A total of 15 species of fishes were identified from the sellers who catch fishes from the Sitheri Lake. The physico-chemical parameters of water varied according to the seasonal fluctuations in rainfall pattern. In general, wetland management for waterbirds of these two lakes should focus on providing suitable nesting habitats and available food resources for dependant avifauna. Management of invertebrates, amphibians, and fishes in these two lakes is one technique that can be used to provide foraging opportunities for waterbirds. An integrated approach and increased co-operation would result in the rational use of this freshwater resource leading to improved standards of living around this lake.
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Riedinger-Whitmore, Melanie Ann. "Using palaeoecological and palaeoenvironmental records to guide restoration, conservation and adaptive management of Ramsar freshwater wetlands: lessons from the Everglades, USA." Marine and Freshwater Research 67, no. 6 (2016): 707. http://dx.doi.org/10.1071/mf14319.
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The Everglades, the largest Ramsar wetland in the USA, is a spatially complex mosaic of freshwater habitats heavily impacted by agriculture, urban land use, and efforts to manage water resources in southern Florida. Restoration and conservation of these habitats is challenging because they experience different threats, and require different water levels, hydroperiods and disturbances. Historically, Everglades hydrology was maintained by seasonal precipitation and surface-water flows, but was significantly altered in the 20th century to foster agriculture and urban growth. Everglades palaeoecological and palaeoenvironmental studies provide opportunities to examine spatial and temporal variability in wetland conditions, and document past climate and anthropogenic influences on plant succession and habitat persistence since the mid-Holocene. This paper summarises key Everglades palaeoecological and palaeoenvironmental research, and highlights lessons learned about the evolution of the ecosystem, historical variability, and natural and anthropogenic influences. These lessons have been used in defining reference conditions and community targets in current efforts to restore the Everglades. Palaeoenvironmental and palaeoecological studies enhance our understanding about properties that define and contribute to the ecological character of wetlands, and they can identify criteria that are important for restoration and conservation projects in Ramsar-listed wetlands.
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Mandal, Mehedi Hasan, Anup Kumar Dey, Arindam Roy, and Giyasuddin Siddique. "Ecosystem Services of Chariganga and Arpara Beel in Nadia District, West Bengal: A Geographical Enquiry." Space and Culture, India 8, no. 2 (September 28, 2020): 155–67. http://dx.doi.org/10.20896/saci.v8i2.742.
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The ecological set up of the deltaic Bengal has immensely been benefitted by the ecosystem services extended by the freshwater wetlands. Along with the diverse ecological benefits, those floodplain wetlands serve the adjacent agrarian community through the provision of free goods and services. The present study has attempted to identify the ecological resources provided by the Chariganga and Arpara Beel and its impact on the livelihood patterns of the rural inhabitants. Both qualitative and quantitative techniques have been used for the study. Ecosystem Service Index (ESI) has been computed to quantify the values of ecosystem services in each category for the dry and wet periods. Nearly 33 ecosystem services are identified which have significantly influenced the socio-economic lifestyle of the inhabitants of three adjacent villages like Arpara, Gotpara, and Sultanpur but not homogeneously in terms of space, time, and status of stakeholders. The computed ESI values reveal that the maximum index value in each category of ecosystem services has been recorded at Chariganga Wetland in both dry and wet seasons. Moreover, the fluctuation of ESI between the two seasons is least at Chariganga Wetland (0.03) compared to Arpara Wetland (0.28). Spatio-temporal variation in availability of resources has conspicuously altered the yearlong utilisation pattern of wetlands’ resources and put a noticeable imprint upon the diverse economic activities and cultural practices of the beneficiaries. The seasonal transformation of a large segment of the studied wetlands in wet and dry months has noticeably influenced the livelihood strategies of the natives. As a consequence, dynamism in utilisation pattern and contrasted societal views concerning the wetland-people interdependency has come into existence.
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Potter, Christopher. "Recovery Rates of Wetland Vegetation Greenness in Severely Burned Ecosystems of Alaska Derived from Satellite Image Analysis." Remote Sensing 10, no. 9 (September 12, 2018): 1456. http://dx.doi.org/10.3390/rs10091456.
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The analysis of wildfire impacts at the scale of less than a square kilometer can reveal important patterns of vegetation recovery and regrowth in freshwater Arctic and boreal regions. For this study, NASA Landsat burned area products since the year 2000, and a near 20-year record of vegetation green cover from the MODIS (Moderate Resolution Imaging Spectroradiometer) satellite sensor were combined to reconstruct the recovery rates and seasonal profiles of burned wetland ecosystems in Alaska. Region-wide breakpoint analysis results showed that significant structural change could be detected in the 250-m normalized difference vegetation index (NDVI) time series for the vast majority of wetland locations in the major Yukon river drainages of interior Alaska that had burned at high severity since the year 2001. Additional comparisons showed that wetland cover locations across Alaska that have burned at high severity subsequently recovered their green cover seasonal profiles to relatively stable pre-fire levels in less than 10 years. Negative changes in the MODIS NDVI, namely lower greenness in 2017 than pre-fire and incomplete greenness recovery, were more commonly detected in burned wetland areas after 2013. In the years prior to 2013, the NDVI change tended to be positive (higher greenness in 2017 than pre-fire) at burned wetland elevations lower than 400 m, whereas burned wetland locations at higher elevation showed relatively few positive greenness recovery changes by 2017.
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Liu, Hai, Hongmeng Yuan, Shimian Wang, Liang Zheng, and Ming Liao. "Spatiotemporal Dynamics of Water Body Changes and Their Influencing Factors in the Seasonal Lakes of the Poyang Lake Region." Water 13, no. 11 (May 30, 2021): 1539. http://dx.doi.org/10.3390/w13111539.
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Poyang Lake is the largest freshwater lake in China, an internationally important wetland and the largest migratory bird habitat in Asia. There are numerous seasonal lakes in the Poyang Lake region, and these lakes create a complex and diverse wetland landscape and serve as the main activity area for migratory birds. Seasonal lakes have significant effects on hydrological and ecological processes and are highly susceptible to various changes, but research on seasonal lakes is relatively limited. Based on long-term remote sensing images, this study analyzed the spatiotemporal variation characteristics of seasonal lakes and their influencing factors and ecological effects. The conclusions were as follows: the average water area of seasonal lakes showed a unimodal change during the year, reaching a maximum in July and a minimum in January. The interannual water area fluctuated greatly, and the overall water area showed a small downward trend. In terms of spatial variation, the seasonal lakes were connected with the main lake in the wet season and separated from the main lake in the dry season. Among the natural factors, the influences of temperature, evaporation, and rainfall on the water area of the seasonal lakes were successively reduced. In addition, the incoming water from the Yangtze River had an important influence. Among the human factors, the traditional fishing method “enclosing sublakes in autumn” had the greatest impact on the water area in a specific period, followed by the indirect impact of the Three Gorges Project.
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Asunbo, E. B., and F. B. G. Tanee. "Seasonal variations in physicochemistry of water and sediment of a degraded freshwater wetland ecosystem: a case study of Ipare wetland in Ondo State, Nigeria." Nigerian Journal of Botany 35, no. 1 (September 29, 2022): 59–68. http://dx.doi.org/10.4314/njbot.v35i1.7.
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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.
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Siwakoti, Mohan, and Jhamak B. Karki. "Conservation status of Ramsar sites of Nepal Tarai: an overview." Botanica Orientalis: Journal of Plant Science 6 (March 15, 2010): 76–84. http://dx.doi.org/10.3126/botor.v6i0.2914.
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Nepal houses only inland freshwater wetlands, ranging from floodplains of snow-melt-fed cold Himalayan rivers, warm rivers originating in the mid hills, high altitudinal glacial lakes to hot springs, ponds, ox-bow lakes, marshes and swamps. These wetlands support several endemic and globally threatened species of flora and fauna. Besides, wetland sites have significant recreational, religio-cultural and spiritual values. There are over 240 wetland sites in Nepal, of which 163 are in the Terai (plain lowland). Wetlands found in Tarai are comparatively more inventoried than the wetlands of mountains and the Himalayan regions of the country. The Terai region (below 300 m) covers about 14% of the country's total area, where half of Nepal's total populations exist. About 11% population of the country is wetland dependent; majority of them are living in the Terai region. The country has nine Ramsar sites, of which, four are in the Tarai region. Among them, two sites (Koshi Tappu wetland, and Beeshazar and associated lakes) lie inside the protected areas and two sites (Ghodaghodi Lake area and Jagadishpur Reservoir) are distributed outside the protected areas. The Koshi Tappu wetland lies along the floodplains of the Sapta Koshi River in the eastern Tarai within the Koshi Tappu Wildlife Reserve. It is the first Ramsar site in Nepal. Beeshazar and associated lakes lies in the buffer zone of the Chitwan National Park along the inner Tarai of Central Nepal. The Ghodaghodi Lake Area (2500 ha) lies in the far western Nepal, and comprises about 14 large and small ox-bow lakes/ponds with associated marshes, swamps, river/streams, springs, seasonal marshy grasslands and human made wetlands, out of them, Ghodaghodi Lake (138 ha) is the largest natural lake in the Nepal's Tarai. The lake system falls between the Bardia National Park and the Suklaphanta Wildlife Reserve of the country and the surrounding forest functions as an important corridor for the movement of wildlife between these as well as the Tarai and the northern Siwalik hills. Similarly, the Jagadishpur Reservoir (225 ha) which lies in Central Nepal's Tarai is the largest man-made wetland in Nepal for irrigation purpose. It is an important site for migratory and resident birds. In this paper we highlight the status, threats, conservation issues and management practices of these Ramsar sites lying in Nepal Tarai. Key-words: Ghodaghodi Lake; Jagdishpur Reservoir; Nepal Tarai; outside protected area; wetlands.DOI: 10.3126/botor.v6i0.2914 Botanica Orientalis - Journal of Plant Science (2009) 6: 76-84
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Manzoni, Stefano, Giorgos Maneas, Anna Scaini, Basil E. Psiloglou, Georgia Destouni, and Steve W. Lyon. "Understanding coastal wetland conditions and futures by closing their hydrologic balance: the case of the Gialova lagoon, Greece." Hydrology and Earth System Sciences 24, no. 7 (July 15, 2020): 3557–71. http://dx.doi.org/10.5194/hess-24-3557-2020.
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Abstract. Coastal wetlands and lagoons are under pressure due to competing demands for freshwater resources and climatic changes, which may increase salinity and cause a loss of ecological functions. These pressures are particularly high in Mediterranean regions with high evaporative demand compared to precipitation. To manage such wetlands and maximize their provision of ecosystem services, their hydrologic balance must be quantified. However, multiple channels, diffuse surface water exchanges, and diverse groundwater pathways complicate the quantification of different water balance components. To overcome this difficulty, we developed a mass balance approach based on coupled water and salt balance equations to estimate currently unknown water exchange fluxes through the Gialova lagoon, southwestern Peloponnese, Greece. Our approach facilitates quantification of both saline and freshwater exchange fluxes, using measured precipitation, water depth and salinity, and estimated evaporation rates over a study period of 2 years (2016–2017). While water exchanges were dominated by evaporation and saline water inputs from the sea during the summer, precipitation and freshwater inputs were more important during the winter. About 40 % and 60 % of the freshwater inputs were from precipitation and lateral freshwater flows, respectively. Approximately 70 % of the outputs was due to evaporation, with the remaining 30 % being water flow from the lagoon to the sea. Under future drier and warmer conditions, salinity in the lagoon is expected to increase, unless freshwater inputs are enhanced by restoring hydrologic connectivity between the lagoon and the surrounding freshwater bodies. This restoration strategy would be fundamental to stabilizing the current wide seasonal fluctuations in salinity and maintain ecosystem functionality but could be challenging to implement due to expected reductions in water availability in the freshwater bodies supporting the lagoon.
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Knox, Sara H., Sheel Bansal, Gavin McNicol, Karina Schafer, Cove Sturtevant, Masahito Ueyama, Alex C. Valach, et al. "Identifying dominant environmental predictors of freshwater wetland methane fluxes across diurnal to seasonal time scales." Global Change Biology 27, no. 15 (May 29, 2021): 3582–604. http://dx.doi.org/10.1111/gcb.15661.
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Osland, Michael J., Eugenio González, and Curtis J. Richardson. "Coastal Freshwater Wetland Plant Community Response to Seasonal Drought and Flooding in Northwestern Costa Rica." Wetlands 31, no. 4 (May 5, 2011): 641–52. http://dx.doi.org/10.1007/s13157-011-0180-9.
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Pisani, Oliva, J. William Louda, and Rudolf Jaffé. "Biomarker assessment of spatial and temporal changes in the composition of flocculent material (floc) in the subtropical wetland of the Florida Coastal Everglades." Environmental Chemistry 10, no. 5 (2013): 424. http://dx.doi.org/10.1071/en13062.
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Environmental context Flocculent material (floc) in freshwater and coastal areas of the Florida Everglades plays an important role in food web dynamics and nutrient cycling. Using biomarkers and pigment chemotaxonomy, we determined the organic matter composition of floc from different environments in the Everglades, and found that it is dominated by local biomass inputs and influenced by hydrological regimes. With the on-going restoration of the Florida Everglades, it is important to gain a better understanding of the biogeochemical dynamics of floc, including its sources, transformations and reactivity. Abstract Flocculent material (floc) is an important energy source in wetlands. In the Florida Everglades, floc is present in both freshwater marshes and coastal environments and plays a key role in food webs and nutrient cycling. However, not much is known about its environmental dynamics, in particular its biological sources and bio-reactivity. We analysed floc samples collected from different environments in the Florida Everglades and applied biomarkers and pigment chemotaxonomy to identify spatial and seasonal differences in organic matter sources. An attempt was made to link floc composition with algal and plant productivity. Spatial differences were observed between freshwater marsh and estuarine floc. Freshwater floc receives organic matter inputs from local periphyton mats, as indicated by microbial biomarkers and chlorophyll-a estimates. At the estuarine sites, the floc is dominated by mangrove as well as diatom inputs from the marine end-member. The hydroperiod (duration and depth of inundation) at the freshwater sites influences floc organic matter preservation, where the floc at the short-hydroperiod site is more oxidised likely due to periodic dry-down conditions. Seasonal differences in floc composition were not consistent and the few that were observed are likely linked to the primary productivity of the dominant biomass (periphyton in the freshwater marshes and mangroves in the estuarine zone). Molecular evidence for hydrological transport of floc material from the freshwater marshes to the coastal fringe was also observed. With the on-going restoration of the Florida Everglades, it is important to gain a better understanding of the biogeochemical dynamics of floc, including its sources, transformations and reactivity.
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Gan, Guojing, Yuanbo Liu, Xin Pan, Xiaosong Zhao, Mei Li, and Shigang Wang. "Seasonal and Diurnal Variations in the Priestley–Taylor Coefficient for a Large Ephemeral Lake." Water 12, no. 3 (March 17, 2020): 849. http://dx.doi.org/10.3390/w12030849.
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The Priestley–Taylor equation (PTE) is widely used with its sole parameter (α) set as 1.26 for estimating the evapotranspiration (ET) of water bodies. However, variations in α may be large for ephemeral lakes. Poyang Lake, which is the largest freshwater lake in China, is water-covered and wetland-covered during its high-water and low-water periods, respectively, over a year. This paper examines the seasonal and diurnal variations in α using eddy covariance observation data for Poyang Lake. The results show that α = 1.26 is overall feasible for both periods at daily and subdaily scales. No obvious seasonal trend was observed, although the standard deviation in α for the wetland was larger than that for the water surface. The mean bias in evaporation estimations using the PTE was less than 5 W·m−2 during both periods, and the root mean square errors were much smaller than the average evaporation measurements at daily scale. U-shaped diurnal patterns of α were found during both periods, due partly to the negative correlation between α and the available energy (A). Compared to the vapor pressure deficit (VPD), wind speed (u) exerts a larger contribution to these variations. In addition, u is positively correlated with α during both periods, however, VPD was positively and negatively correlated with α during the high-water and low-water periods, respectively. Subdaily α exhibited contrasting clusters in the (u, VPD) plane under the same available energy ranges. Our study highlights the seasonal and diurnal course of α and suggests the careful use of PTE at subdaily scales.
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Saha, Amartya K., Japhet Kashaigili, Fredrick Mashingia, Halima Kiwango, Mercy Asha Mohamed, Michael Kimaro, Mathias Msafiri Igulu, et al. "Determination of Environmental Flows in Data-Poor Estuaries—Wami River Estuary in Saadani National Park, Tanzania." Hydrology 10, no. 2 (January 23, 2023): 33. http://dx.doi.org/10.3390/hydrology10020033.
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Land use changes and mounting water demands reduce freshwater inflows into estuaries, impairing estuarine ecosystems and accelerating coastal seawater intrusion. However, determining minimum river inflows for management guidelines is hampered by a lack of ecosystem-flow link data. This study describes the development of freshwater inflow guidelines for the Wami Estuary, combining scarce river flow data, hydrological modeling, inferring natural salinity regime from vegetation zonation and investigating freshwater requirements of people/wildlife. By adopting the Building Blocks Methodology, a detailed Environmental Flows Assessment was performed to know the minimum water depth/quality seasonal requirements for vegetation, terrestrial/aquatic wildlife and human communities. Water depth requirements were assessed for drought and normal rainfall years; corresponding discharges were obtained by a hydrological model (HEC-RAS) developed for the river channel upstream of estuary. Recommended flows were well within historically occurring flows. However, given the rapidly increasing water demand coupled with reduction in basin water storage due to deforestation/wetland loss, it is critical to ensure these minimum flows are present, without which essential ecosystem services (fisheries, water quality, mangrove forest resources and wildlife/tourism) will be jeopardized. The EFA process is described in painstaking detail to provide a reference for undertaking similar studies in data-poor regions worldwide.
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Jin, Changhao. "Biodiversity dynamics of freshwater wetland ecosystems affected by secondary salinisation and seasonal hydrology variation: a model-based study." Hydrobiologia 598, no. 1 (October 12, 2007): 257–70. http://dx.doi.org/10.1007/s10750-007-9161-7.
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Khoiyangbam, R. S., and Suraj S. Chingangbam. "Assessing seasonal variation of diffusive nitrous oxide emission from freshwater wetland in Keibul Lamjao National Park, Manipur Northeast India." Atmospheric Environment: X 13 (January 2022): 100147. http://dx.doi.org/10.1016/j.aeaoa.2022.100147.
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Jefferies, Robert L., and Kate A. Edwards. "Soluble carbohydrate content of shoots of Arctic wetland plants that are consumed by lesser snow geese." Botany 86, no. 9 (September 2008): 995–1001. http://dx.doi.org/10.1139/b08-051.
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We recorded seasonal changes in the total amounts of soluble carbohydrates in shoots of salt- and fresh-water coastal plants at La Pérouse Bay, northern Manitoba, to determine whether adult snow geese and their goslings selected forage rich in soluble carbohydrates during the breeding season. The selection of forage plants in spring and summer by adults and goslings was strongly linked to the presence of high amounts of soluble carbohydrates in tissues: on the order of 100 mg·g–1 dry mass. When the content fell as a result of shoot development or leaf senescence, the geese switched to alternative sources of forage. The extent to which individual shoots rich in soluble carbohydrates of the primary freshwater forage species are grazed depends on the local density of breeding geese at the study site, which has fallen in the last decade as a result of the earlier destruction of much of the coastal vegetation by foraging geese.
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Reiter, Matthew E., Nathan K. Elliott, Dennis Jongsomjit, Gregory H. Golet, and Mark D. Reynolds. "Impact of extreme drought and incentive programs on flooded agriculture and wetlands in California’s Central Valley." PeerJ 6 (June 29, 2018): e5147. http://dx.doi.org/10.7717/peerj.5147.
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BackgroundBetween 2013 and 2015, a large part of the western United States, including the Central Valley of California, sustained an extreme drought. The Central Valley is recognized as a region of hemispheric importance for waterbirds, which use flooded agriculture and wetlands as habitat. Thus, the impact of drought on the distribution of surface water needed to be assessed to understand the effects on waterbird habitat availability.MethodsWe used remote sensing data to quantify the impact of the recent extreme drought on the timing and extent of waterbird habitat during the non-breeding season (July–May) by examining open water in agriculture (rice, corn, and other crops) and managed wetlands across the Central Valley. We assessed the influence of habitat incentive programs, particularly The Nature Conservancy’s BirdReturns and The Natural Resources Conservation Service’s Waterbird Habitat Enhancement Program (WHEP), at offsetting habitat loss related to drought.ResultsOverall, we found statistically significant declines in open water in post-harvest agriculture (45–80% declines) and in managed wetlands (39–60% declines) during the 2013–2015 drought compared to non-drought years during the period of 2000–2011. Crops associated with the San Joaquin Basin, specifically corn, as well as wetlands in that part of the Central Valley exhibited larger reductions in open water than rice and wetlands in the Sacramento Valley. Semi-permanent wetlands on protected lands had significantly lower (39–49%) open water in the drought years than those on non-protected lands while seasonal wetlands on protected lands had higher amounts of open water. A large fraction of the daily open water in rice during certain times of the year, particularly in the fall for BirdReturns (61%) and the winter for WHEP (100%), may have been provided through incentive programs which underscores the contribution of these programs. However, further assessment is needed to know how much the incentive programs directly offset the impact of drought in post-harvest rice by influencing water management or simply supplemented funding for activities that might have been done regardless.DiscussionOur landscape analysis documents the significant impacts of the recent extreme drought on freshwater wetland habitats in the Central Valley, the benefits of incentive programs, and the value of using satellite data to track surface water and waterbird habitats. More research is needed to understand subsequent impacts on the freshwater dependent species that rely on these systems and how incentive programs can most strategically support vulnerable species during future extreme drought.
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Gilliam, Frank S., Jacob W. Hardin, Jacob A. Williams, and Rachel L. Lackaye. "The University of West Florida Campus Ecosystem Study: Spatial and Temporal Variation in Water Quality at Thompson Bayou." Water 14, no. 18 (September 17, 2022): 2916. http://dx.doi.org/10.3390/w14182916.
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Much of our understanding of factors influencing stream chemistry comes from studies of montane forests, whereas far less work has focused on streams of coastal areas that integrate a homogeneous, flat topography and interactions with the bodies of water into which they drain, especially involving tidal fluxes. Fewer still do so in the context of an urban interface, especially that of a college campus. This study assessed the water quality of Thompson Bayou, a freshwater stream entering the University of West Florida campus in a wetland after flowing through the urban property with impacted water quality. We measured temperature, pH, dissolved O2 (DO), and specific conductivity (SC) for one year at eight sites along Thompson Bayou from campus to the Escambia River. All variables, except temperature, varied spatially, with consistent increases in DO and SC toward the river of 10% and 75%, respectively. Variables exhibited temporal patterns of significant seasonal variation, especially temperature, increasing from a January minimum of 14 °C to a summer maximum of 28 °C. These results suggest that, in general, the biogeochemistry of coastal streams such as Thompson Bayou can be influenced by numerous factors, including (1) wetland processes, (2) interactions of the stream channel with forested uplands, and (3) tidal fluxes.
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Novriadhy, D., T. Karenina, S. Maryani, D. Yesi, Efriandi, W. T. Defriyanti, O. Juairiyah, and O. Komalasari. "Shallot (Allium cepa L.) Planted In The Ts-of-RAMSAR-Classification Ecosystem Is Still Beneficial In The COVID-19 Treatment." IOP Conference Series: Earth and Environmental Science 995, no. 1 (April 1, 2022): 012024. http://dx.doi.org/10.1088/1755-1315/995/1/012024.
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Abstract Rich in quercetin, shallot (Allium cepa L.) use is beneficial in controlling the COVID-19 pandemic since effective vaccines and pharmacotherapy are still in development. The study aimed to characterize functional groups of shallot tubers planted in the inorganic soil of the seasonal freshwater-wetland (IS-SFW)/Ts-of-RAMSAR-classification ecosystem. The shallot tubers that grew in IS-SFW for 60 days were manually harvested, sun-dried for seven days, and stored for two months before been pressed to produce sample juices. The peaks of wavenumber resulted from FTIR analysis were compared to the infrared database to determine possibly functional groups. The findings showed spectra changed in the fingerprint but not in the mid-IR other regions, indicated the IS-SFW did not affect functional groups beneficial in the COVID-19 treatment. The study concluded that shallot planted in IS-SFW is still beneficial in the COVID-19 treatment.
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Avellan, Astrid, Marie Simonin, Steven M. Anderson, Nicholas K. Geitner, Nathan Bossa, Eleanor Spielman-Sun, Emily S. Bernhardt, et al. "Differential Reactivity of Copper- and Gold-Based Nanomaterials Controls Their Seasonal Biogeochemical Cycling and Fate in a Freshwater Wetland Mesocosm." Environmental Science & Technology 54, no. 3 (January 17, 2020): 1533–44. http://dx.doi.org/10.1021/acs.est.9b05097.
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Jager, Henriette I., Rebecca A. Efroymson, and Latha M. Baskaran. "Avoiding Conflicts between Future Freshwater Algae Production and Water Scarcity in the United States at the Energy-Water Nexus." Water 11, no. 4 (April 20, 2019): 836. http://dx.doi.org/10.3390/w11040836.
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Sustainable production of algae will depend on understanding trade-offs at the energy-water nexus. Algal biofuels promise to improve the environmental sustainability profile of renewable energy along most dimensions. In this assessment of potential US freshwater production, we assumed sustainable production along the carbon dimension by simulating placement of open ponds away from high-carbon-stock lands (forest, grassland, and wetland) and near sources of waste CO 2 . Along the water dimension, we quantified trade-offs between water scarcity and production for an ‘upstream’ indicator (measuring minimum water supply) and a ‘downstream’ indicator (measuring impacts on rivers). For the upstream indicator, we developed a visualization tool to evaluate algae production for different thresholds for water surplus. We hypothesized that maintaining a minimum seasonal water surplus would also protect river habitat for aquatic biota. Our study confirmed that ensuring surplus water also reduced the duration of low-flow events, but only above a threshold. We also observed a trade-off between algal production and the duration of low-flow events in streams. These results can help to guide the choice of basin-specific sustainability targets to avoid conflicts with competing water users at this energy-water nexus. Where conflicts emerge, alternative water sources or enclosed photobioreactors may be needed for algae cultivation.
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Yang, Guishan, Qi Zhang, Rongrong Wan, Xijun Lai, Xia Jiang, Ling Li, Huichao Dai, Guangchun Lei, Jianchi Chen, and Yongjun Lu. "Lake hydrology, water quality and ecology impacts of altered river–lake interactions: advances in research on the middle Yangtze river." Hydrology Research 47, S1 (November 21, 2016): 1–7. http://dx.doi.org/10.2166/nh.2016.003.
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Water and mass exchange between rivers and lakes are key processes that maintain the health of the ecology of river–lake systems. Alteration to river–lake interactions have great impacts on water and mass balances. Naturally connected to the middle Yangtze River are the Poyang Lake and Dongting Lake, which are the largest and the second largest freshwater lakes in China. The operation of the Three Gorges Dam (TGD) in the upper Yangtze River was found to have substantial impacts on the middle Yangtze river–lake system. In the past decade, unusual seasonal dryness was evident in the two lakes. Considerable deviations in lake water quality and wetland ecosystem were also detected. In order to explore and distinguish the causal factors influencing the river–lake system, the Ministry of Sciences and Technology (China) launched a research project in 2012, the National Basic Research Program of China (973 Program) (2012CB417000). This article provides an overview of advances in this research, including the evolution of the river–lake interactions, the impacts of the TGD, and the influences on lake hydrology, water quality, and ecosystem. The 20 papers in this issue deliver part of the research outcomes of this project.
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Day, John, Reed Goodman, Zhongyuan Chen, Rachael Hunter, Liviu Giosan, and Yanna Wang. "Deltas in Arid Environments." Water 13, no. 12 (June 17, 2021): 1677. http://dx.doi.org/10.3390/w13121677.
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Due to increasing water use, diversion and salinization, along with subsidence and sea-level rise, deltas in arid regions are shrinking worldwide. Some of the most ecologically important arid deltas include the Colorado, Indus, Nile, and Tigris-Euphrates. The primary stressors vary globally, but these deltas are threatened by increased salinization, water storage and diversion, eutrophication, and wetland loss. In order to make these deltas sustainable over time, some water flow, including seasonal flooding, needs to be re-established. Positive impacts have been seen in the Colorado River delta after flows to the delta were increased. In addition to increasing freshwater flow, collaboration among stakeholders and active management are necessary. For the Nile River, cooperation among different nations in the Nile drainage basin is important. River flow into the Tigris-Euphrates River delta has been affected by politics and civil strife in the Middle East, but some flow has been re-allocated to the delta. Studies commissioned for the Indus River delta recommended re-establishment of some monthly water flow to maintain the river channel and to fight saltwater intrusion. However, accelerating climate impacts, socio-political conflicts, and growing populations suggest a dire future for arid deltas.
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Klok, Peter F., and Gerard van der Velde. "Plant traits and environment: floating leaf blade production and turnover of waterlilies." PeerJ 5 (April 27, 2017): e3212. http://dx.doi.org/10.7717/peerj.3212.
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Floating leaf blades of waterlilies fulfill several functions in wetland ecosystems by production, decomposition and turnover as well as exchange processes. Production and turnover rates of floating leaf blades of three waterlily species, Nuphar lutea (L.) Sm., Nymphaea alba L. and Nymphaea candida Presl, were studied in three freshwater bodies, differing in trophic status, pH and alkalinity. Length and percentages of leaf loss of marked leaf blades were measured weekly during the growing season. Area and biomass were calculated based on leaf length and were used to calculate the turnover rate of floating leaf blades. Seasonal changes in floating leaf production showed that values decreased in the order: Nymphaea alba, Nuphar lutea, Nymphaea candida. The highest production was reached for Nuphar lutea and Nymphaea alba in alkaline, eutrophic water bodies. The production per leaf was relatively high for both species in the acid water body. Nymphaea candida showed a very short vegetation period and low turnover rates. The ratio Total potential leaf biomass/Maximum potential leaf biomass (P/Bmax) of the three species ranged from 1.35–2.25. The ratio Vegetation period (Period with floating leaves)/Mean leaf life span ranged from 2.94–4.63, the ratio Growth period (Period with appearance of new floating leaves)/Vegetation period from 0.53–0.73. The clear differences between Nymphaea candida versus Nuphar lutea and Nymphaea alba, may be due to adaptations of Nymphaea candida to an Euro-Siberic climate with short-lasting summer conditions.
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Pandey, Gaurav. "Wetlands and their Role in Water Conservation: A Review." International Journal of Advance Research and Innovation 4, no. 1 (2016): 84–88. http://dx.doi.org/10.51976/ijari.411612.
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A wetland is an area of land whose soil is saturated with moisture either permanently or seasonally. Such areas may also be covered partially or completely by shallow pools of water. Wetlands include swamps, marshes, and bogs. The water found in wetlands can be saltwater, freshwater, or brackish. The world's largest wetland is the Pantanal which straddles Brazil, Bolivia and Paraguayan South America. Wetlands are considered the most biologically diverse of all ecosystems. Plant life found in wetlands includes mangrove, water lilies, cattails, sedges, tamarack, black etc. A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. Saltwater is water from a sea or ocean. Fresh water is naturally occurring water on the Earth's surface in bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Brackish water is water that has more salinity than fresh water, but not as much as seawater spruce, cypress, gum tree, and many others. Animal life includes many different amphibians, reptiles, birds, insects, and mammals. In many locations, such as the United Kingdom, Iraq, South Africa and the United States, wetlands are the subject of conservation efforts and biodiversity Action Plans.
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Jammet, Mathilde, Sigrid Dengel, Ernesto Kettner, Frans-Jan W. Parmentier, Martin Wik, Patrick Crill, and Thomas Friborg. "Year-round CH<sub>4</sub> and CO<sub>2</sub> flux dynamics in two contrasting freshwater ecosystems of the subarctic." Biogeosciences 14, no. 22 (November 21, 2017): 5189–216. http://dx.doi.org/10.5194/bg-14-5189-2017.
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Abstract. Lakes and wetlands, common ecosystems of the high northern latitudes, exchange large amounts of the climate-forcing gases methane (CH4) and carbon dioxide (CO2) with the atmosphere. The magnitudes of these fluxes and the processes driving them are still uncertain, particularly for subarctic and Arctic lakes where direct measurements of CH4 and CO2 emissions are often of low temporal resolution and are rarely sustained throughout the entire year. Using the eddy covariance method, we measured surface–atmosphere exchange of CH4 and CO2 during 2.5 years in a thawed fen and a shallow lake of a subarctic peatland complex. Gas exchange at the fen exhibited the expected seasonality of a subarctic wetland with maximum CH4 emissions and CO2 uptake in summer, as well as low but continuous emissions of CH4 and CO2 throughout the snow-covered winter. The seasonality of lake fluxes differed, with maximum CO2 and CH4 flux rates recorded at spring thaw. During the ice-free seasons, we could identify surface CH4 emissions as mostly ebullition events with a seasonal trend in the magnitude of the release, while a net CO2 flux indicated photosynthetic activity. We found correlations between surface CH4 emissions and surface sediment temperature, as well as between diel CO2 uptake and diel solar input. During spring, the breakdown of thermal stratification following ice thaw triggered the degassing of both CH4 and CO2. This spring burst was observed in 2 consecutive years for both gases, with a large inter-annual variability in the magnitude of the CH4 degassing. On the annual scale, spring emissions converted the lake from a small CO2 sink to a CO2 source: 80 % of total annual carbon emissions from the lake were emitted as CO2. The annual total carbon exchange per unit area was highest at the fen, which was an annual sink of carbon with respect to the atmosphere. Continuous respiration during the winter partly counteracted the fen summer sink by accounting for, as both CH4 and CO2, 33 % of annual carbon exchange. Our study shows (1) the importance of overturn periods (spring or fall) for the annual CH4 and CO2 emissions of northern lakes, (2) the significance of lakes as atmospheric carbon sources in subarctic landscapes while fens can be a strong carbon sink, and (3) the potential for ecosystem-scale eddy covariance measurements to improve the understanding of short-term processes driving lake–atmosphere exchange of CH4 and CO2.
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Koronkiewicz, Thomas J., Mark K. Sogge, Charles Van Riper, and Eben H. Paxton. "Territoriality, Site Fidelity, and Survivorship of Willow Flycatchers Wintering in Costa Rica." Condor 108, no. 3 (August 1, 2006): 558–70. http://dx.doi.org/10.1093/condor/108.3.558.
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AbstractWe studied wintering Willow Flycatchers (Empidonax traillii) in two seasonal freshwater wetland habitats in northwestern Costa Rica during five boreal winters, to determine habitat occupancy, overwinter and between-year site and territory fidelity, and the degree to which the sexes maintain and defend winter territories. Both males and females used agonistic displays, song, and other vocalizations to maintain and defend mutually exclusive winter territories. Males were generally more abundant than females, but this varied by site and year. There was no significant difference in male and female territory size, nor any indication of sexual habitat segregation. Similarity in morphology and aggressiveness between the sexes may account for the lack of habitat segregation and the ability of females to maintain territories at wintering sites. Each year, 80%–92% of banded flycatchers that were present in midwinter remained at the site until late winter; of these, 86%–100% of individuals maintained the same territories throughout the entire period. We also observed nonterritorial floaters that subsequently established and held winter territories. Between-year site fidelity averaged 68%, and almost all returning birds established territories with boundaries similar to the previous year. Between-year apparent survivorship estimates ranged annually from 54%–72%, with no difference between sites but weak support for higher survivorship of males compared to females. Values for winter site and territory fidelity were generally higher than those reported for other species and for Willow Flycatchers on the breeding grounds; between-year survivorship estimates were similar to those reported for breeding flycatchers.
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Yin, Xueyan, Guanghan Yan, Xing Wang, Daizhong Huang, and Liqiang Li. "Spatiotemporal Distribution Pattern of Phytoplankton Community and Its Main Driving Factors in Dongting Lake, China—A Seasonal Study from 2017 to 2019." Water 14, no. 11 (May 24, 2022): 1674. http://dx.doi.org/10.3390/w14111674.
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As it is the second-largest freshwater lake downstream of the Three Gorges Dam and an important international wetland for migratory birds, there have been concerns about the ecological water health of Dongting Lake for a long time. In the present study, we studied the evolutionary characteristics of water quality in Dongting Lake in three recent years. Moreover, the evolution rules and dominant groups of the phytoplankton community were explored, and the major influencing factors of phytoplankton and their distribution were assessed based on the field survey and detection data from 2017 to 2019. The results indicated that the water quality of Dongting Lake improved in recent years. The concentration of dissolved oxygen (DO) increased by 6.91%, whereas the concentrations of the five-day biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), ammonia nitrogen (NH4+–N), total phosphorus (TP), and total nitrogen (TN) decreased by 17.5%, 13.0%, 33.8%, 7.6%, and 13.3%, respectively. The mean phytoplankton density reached 4.15 × 105 cells·L−1 in September 2017, whereas it was only 1.62 × 105 cells·L−1 in December 2018. There were 15 dominant species belonging to Cyanobacteria, Chlorophyta, Bacillariophyta, Cryptophyta, and Miozoa. Moreover, Fragilaria radians (Kützing) D.M.Williams & Round and Aulacoseiragranulata (Ehrenberg) Simonsen were the dominant populations in all seasons. The Pearson and linear regression analysis also indicated that the composition and distribution of phytoplankton in Dongting Lake were mainly affected by electrical conductivity (Cond), BOD5, potassium permanganate (CODMn), and CODCr, especially in Eastern Dongting Lake. Of course, NH4+–N, TN, and TP were also the main factors affecting the density and species of the phytoplankton community, especially in Western Dongting Lake. Finally, we suggested that local government could take “The relationship between Yangtze River and Dongting Lake”, “The relationship between the seven fed rivers and Dongting Lake”, and “The relationship between human activities and Dongting Lake” as the breakthrough points to guarantee the ecological flow, water environment, and ecological quality of Dongting Lake.
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Pinho, Henrique J. O., and Dina M. R. Mateus. "Sustainable Production of Reclaimed Water by Constructed Wetlands for Combined Irrigation and Microalgae Cultivation Applications." Hydrology 8, no. 1 (February 13, 2021): 30. http://dx.doi.org/10.3390/hydrology8010030.
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Considering the increasing pressure on freshwater resources due to the constant increase in water consumption and insufficient wastewater control and treatment, recovering wastewater is a path to overcoming water scarcity. The present work describes the potential of reusing treated wastewater (reclaimed water) for irrigation and production of microalgae biomass in an integrated way, through experimental evaluation of plant and microalgae growth, and creation of an application model. First, two parallel experiments were conducted to evaluate the use of reclaimed water produced by a constructed wetland filled with a mix of solid waste: the irrigation of a set of small pots filled with soil and planted with Tagetes patula L., and the cultivation of microalgae Chlorella sp. and a mixed microalgae population with predominant species of the genus Scenedesmus sp. in shaken flasks and tubular bubble column photobioreactors. Results indicated no negative effects of using the reclaimed water on the irrigated plants and in the cultivated microalgae. The growth indicators of plants irrigated with reclaimed water were not significantly different from plants irrigated with fertilized water. The growth indicators of the microalgae cultivated with reclaimed water are within the range of published data. Second, to apply the results to a case study, the seasonal variability of irrigation needs in an academic campus was used to propose a conceptual model for wastewater recovery. The simulation results of the model point to a positive combination of using reclaimed water for the irrigation of green spaces and microalgae production, supported by a water storage strategy. Water abstraction for irrigation purposes can be reduced by 89%, and 2074 kg dry weight microalgae biomass can be produced annually. Besides the need for future work to optimize the model and to add economical evaluation criteria, the model shows the potential to be applied to non-academic communities in the perspective of smarter and greener cities.
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Liang, Kang, and Yanzhong Li. "Changes in Lake Area in Response to Climatic Forcing in the Endorheic Hongjian Lake Basin, China." Remote Sensing 11, no. 24 (December 17, 2019): 3046. http://dx.doi.org/10.3390/rs11243046.
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Endorheic lakes are key components of the water cycle and the ecological system in endorheic basins. The endorheic Hongjian Lake wetland is China’s national nature reserve for protecting the vulnerable species of Relict Gull. The Hongjian Lake, once China’s largest desert freshwater lake, has been suffering from severe shrinkage in the last two decades, yet the variations in the lake area and its responses to climate change are poorly understood due to a lack of in situ observations. In this study, using Landsat remote sensing images, the Modified Normalized Difference Water Index, and nonparametric tests, we obtained the Hongjian Lake area changes on the annual, seasonal, and quasi-monthly scales during 1988–2014, analyzed the corresponding variations of the six climatic factors in the Hongjian Lake Basin (HJLB) using satellite-based products, and investigated the multi-scale response characteristics of lake area to climatic forcing using correlation analysis. The results showed that the lake area decreased during 1988–2014, and this process can be divided into two sub-stages, namely the first slight increasing sub-phase in 1988–1999 and the second significant declining sub-phase in 2000–2014. The shifts in patterns of the seasonal cycle had three types: as the natural rhythm of the lake changes has been broken by intensive human activities since the late 1990s, the natural bimodal type I has obviously changed into non-natural bimodal type II and unimodal type III, featured by a declining peak in July–September. The climatic wet/dry regime on multi-scales during 1988–2014 in the HJLB was generally warming and drying, mainly reflected by the increase in temperature (T), arid index (AI) and evaporation (ET0, ETa), and the decrease in the precipitation (Pre) and actual water difference (AWD). There were large differences in the climatic factors at different time scales, especially in the wet and dry seasons. When the lagged effect, the cumulative effect, and the lagged and cumulative combined effect were gradually considered, the correlation coefficient significantly increased, and the direction of the correlation coefficient became coincident with common sense. The correlation analysis identified a lag period of approximately 1–3 years on an annual scale, and a lag period of approximately 1–3 months on a monthly scale. This study could provide a certain scientific reference for climate change detection, water resource management, and species habitat protection in the HJLB and similar endorheic basins or inland arid regions.
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Kennett, Rod, Keith Christian, and Gavin Bedford. "Underwater nesting by the Australian freshwater turtle Chelodina rugosa: effect of prolonged immersion and eggshell thicknesson incubation period, egg survivorship, and hatchling size." Canadian Journal of Zoology 76, no. 6 (June 1, 1998): 1019–23. http://dx.doi.org/10.1139/z98-041.
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The northern long-necked turtle, Chelodina rugosa, occupies seasonally ephemeral freshwater wetlands in thewetdry tropics of northern Australia. The species has a highly unusual nesting strategy in that nesting takes place under waterwhen wetland habitats are flooded. Embryonic development proceeds when floodwaters recede during the annual dry seasonand hatchling emergence coincides with the start of the following wet season. This study examined the influence of duration ofimmersion of eggs on hatchling size and hatching success under laboratory conditions. Prolonged immersion of eggs in waterresults in smaller hatchlings and shorter incubation times, but does not increase egg mortality during incubation. Leaching ofcalcium from the eggshell, resulting in reduced availability of calcium to the developing embryo, may explain the smallerhatchlings and shorter incubation period. Hatchlings from thin-shelled eggs, in which shell formation was incomplete, weresmaller and hatched sooner, indicating that the eggshell plays a role in determining hatchling size and incubation period.Thin-shelled and normal eggs had equivalent egg survivorship, indicating that the eggshell is unimportant in egg survivalduring immersion.
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Carmichael, Mary Jane, and William K. Smith. "Growing season ecophysiology of Taxodium distichum (L.) Rich. (bald cypress) saplings in a restored wetland: a baseline for restoration practice." Botany 94, no. 12 (December 2016): 1115–25. http://dx.doi.org/10.1139/cjb-2016-0147.
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Wetland restoration is a common practice in the southeastern United States, where changing land use patterns have resulted in the widespread degradation of coastal ecosystems. Re-establishment of indigenous vegetation is a fundamental paradigm of restoration practice. In freshwater wetlands, this often includes planting flood-tolerant species such as Taxodium distichum (L.) Rich (bald cypress). While much is known regarding the ecology of this foundational species, research establishing the ecophysiological profile of mature bald cypress under stress-free, baseline conditions is limited. Therefore, a study was undertaken in 2015 to monitor the growing season ecophysiology of a bald cypress stand in a restored coastal wetland. Net photosynthesis was constant in the early to mid-growing season, declining steadily late in the growth season until the visible onset of needle senescence. Patterns in transpiration matched those observed for photosynthesis, whereas needle conductance and chlorophyll fluorescence appeared to track expected patterns associated with needle development. Trees at this site appeared healthy and were reproductively competent. However, long-term monitoring of the stand would help evaluate the ecological sustainability of this restoration project. We advocate for the inclusion of ecophysiological-based vegetation monitoring within restoration projects, enabling a sensitive and early indication of the trajectory of a restoration plan.
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LAWLER, SHARON P., LISA REIMER, TARA THIEMANN, JOHN FRITZ, KATY PARISE, DAVE FELIZ, and DIA-ELDIN ELNAIEM. "EFFECTS OF VEGETATION CONTROL ON MOSQUITOES IN SEASONAL FRESHWATER WETLANDS." Journal of the American Mosquito Control Association 23, no. 1 (March 2007): 66–70. http://dx.doi.org/10.2987/8756-971x(2007)23[66:eovcom]2.0.co;2.
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Groeneveld, Johan C., Fiona MacKay, Baraka Kuguru, and Boniventure Mchomvu. "Socio-ecological change in the Ruvu Estuary in Tanzania, inferred from land-use and land-cover (LULC) analysis and estuarine fisheries." Western Indian Ocean Journal of Marine Science, no. 1/2021 (December 23, 2021): 75–91. http://dx.doi.org/10.4314/wiojms.si2021.1.6.
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Ecosystem goods and services derived from estuaries have sustained coastal livelihoods in the Western Indian Ocean (WIO) region throughout recorded history. Estuaries provide fertile and seasonally irrigated space for planting crops, mangrove products for construction and fuel, and fish as a protein source. Human population growth and an escalating demand for natural resources threaten estuarine critical habitats and their functioning, exacerbated by the effects of climate change. Decadal and seasonal land-use and land-cover (LULC) changes in the Ruvu Estuary in Tanzania were investigated through analysis of Landsat 5/8 and Sentinel-2 satellite images. The estuary is river-dominated and truncated near the coast during high river flow, with tidal influence extending approximately 12 km upstream during low river flow. LULC change detection targeting nine classes (water, developed, barren, forest, grasslands, cultivated, mangroves, wetlands and mudflats) showed that estuary-associated wetlands and mangroves had declined significantly over the past two decades (1995-2016) making way for developed land (growth of Bagamoyo Town), cultivated land (agricultural expansion with increasing population) and grasslands (coastal habitat changes). Seasonal LULC changes were conversion of wetlands to cultivated land after the wet season, and transformation of fallow wetlands to grasslands. The estuarine fishery relied on a small number of mainly freshwater and marine migrant species, compared to a highly diverse mix of mainly marine species in the nearby coastal fishery. The sparsity of quantitative fisheries data, spectral confusion when modelling land-cover change, and absence of household survey data to assess livelihood activities remain major information gaps. Generalized recommendations for improving socio-ecological change studies in WIO estuarine systems are provided.
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Hondula, Kelly L., C. Nathan Jones, and Margaret A. Palmer. "Effects of seasonal inundation on methane fluxes from forested freshwater wetlands." Environmental Research Letters 16, no. 8 (July 23, 2021): 084016. http://dx.doi.org/10.1088/1748-9326/ac1193.
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Gilbert, Heather, Jenna Keany, and David C. Culver. "Response of shallow subterranean freshwater amphipods to habitat drying." Subterranean Biology 28 (November 16, 2018): 15–28. http://dx.doi.org/10.3897/subtbiol.28.30700.
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The ability of three amphipods that occupy shallow subterranean habitats in the lower Potomac Basin of the US (hypotelminorheic), which often dry out seasonally, to withstand desiccation by burrowing in clay was investigated. Both Crangonyxshoemakeri, a wetland species, and Stygobromustenuis, a subterranean species, burrowed in clay in the laboratory after surface water was removed. Gammarusminus, a spring species, did not. All three species exhibited behavioral changes as the habitat dried out.
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Henning, J. A., R. E. Gresswell, and I. A. Fleming. "Use of seasonal freshwater wetlands by fishes in a temperate river floodplain." Journal of Fish Biology 71, no. 2 (August 2007): 476–92. http://dx.doi.org/10.1111/j.1095-8649.2007.01503.x.
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Anderson, Christopher J., and B. Graeme Lockaby. "SEASONAL PATTERNS OF RIVER CONNECTIVITY AND SALTWATER INTRUSION IN TIDAL FRESHWATER FORESTED WETLANDS." River Research and Applications 28, no. 7 (February 9, 2011): 814–26. http://dx.doi.org/10.1002/rra.1489.
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Zhu hang, Goh, Nelda Maelissa, Loh Zhang Zhan, Atik Widiyanti, Winda Umarie, and Eddy Setiadi Soedjono. "Groundwater quality assesment in Ropar wetland between summer season and winter season." Environmental and Toxicology Management 2, no. 2 (September 6, 2022): 14–20. http://dx.doi.org/10.33086/etm.v2i2.3408.
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Water covers 70% of the world’s total surface, but only around 3% of it is freshwater that humans may drink and utilize for other purposes. Because of fast growth in many nations, the quality of groundwater is no longer adequate for human consumption. The objective of the study is to assess the groundwater quality of 18 locations in the Ropar wetland in Punjab, India, in different seasons and different source groundwater. When compared to uncontaminated natural groundwater, the groundwater obtained from the test sites had higher pH values. The amount of groundwater pollution is higher in the summer than in the winter. However, there are many challenges face by the groundwater quality research. The groundwater quality in any region of the world is very important towards the survival of human being. Long-term consumption of polluted groundwater with high levels of heavy metals will result in health issues such as difficulty breathing and renal failure.
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Xu, Xin Wang, Xiao Qin He, and Ju Feng Zhen. "The Soil Respiration Rate Difference of the Different Reclamation Types of Soil on the Freshwater-Wetland During the Non-Growth Season." Advanced Materials Research 671-674 (March 2013): 2709–14. http://dx.doi.org/10.4028/www.scientific.net/amr.671-674.2709.
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Based on a situ experiment in the Yangtze River Region, the CO2 emission flux of the natural wetland and the different reclamation types of soil during the non-growth season were investigated in this paper. The results showed that the contribution of soil respiration (SR) to the atmospheric CO2 concentration is wetland＜dry land＜paddy field..Furthermore, there was a significant positive correlation between the soil respiration and air temperature and soil temperature in three soil type . It concluded that reclamation of fresh water wetland significantly increased SR and soil CO2 emission from soil which was affected greatly by environmental temperature and reduced soil sequestration.
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Wiegner, Tracy N., and Sybil P. Seitzinger. "Seasonal bioavailability of dissolved organic carbon and nitrogen from pristine and polluted freshwater wetlands." Limnology and Oceanography 49, no. 5 (September 2004): 1703–12. http://dx.doi.org/10.4319/lo.2004.49.5.1703.
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Galal, Tarek M., Fatma A. Gharib, Hatim M. Al-Yasi, Khalid A. Al-Mutairi, Khalid H. Mansour, and Ebrahem M. Eid. "Nutrient Remediation Efficiency of the Sedge Plant (Cyperus alopecuroides Rottb.) to Restore Eutrophic Freshwater Ecosystems." Sustainability 14, no. 5 (February 28, 2022): 2823. http://dx.doi.org/10.3390/su14052823.
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The current study investigated the nutrients removal efficiency of the sedge macrophyte Cyperus alopecuroides to treat water eutrophication, besides evaluating the recycling possibility of the harvested material. Samples of sediment, water, and plant tissues were taken seasonally from six polluted and three unpolluted locations for this investigation. The growth properties of C. alopecuroides showed remarkable seasonal differences in plant density and biomass, with the maximum values (7.1 individual/m2 and 889.6 g/m2, respectively) obtained during summer and the minimum (4.1 individual/m2 and 547.2 g/m2, respectively) in winter. In polluted locations, the above-ground tissues had an efficiency to remove more contents of N and P (11.9 and 3.8 g/m2, respectively) than in unpolluted ones (7.1 and 3.4 g/m2, respectively). The high-nutrient standing stock of C. alopecuroides supports its potential use for nutrient removal from eutrophic wetlands. The tissues of C. alopecuroides had the maximum nutrients removal efficiency to remediate great amounts of Na, K, and N in summer, and Ca, P, and Mg in spring. Above- and below-ground parts of C. alopecuroides from unpolluted locations can be considered as a rough forage for beef cattle, dairy cattle, goats, and sheep. The present study indicated the potential of C. alopecuroides in restoring eutrophic freshwater ecosystems, and, thus, it can be used in similar habitats worldwide.