Pub Date : 2023-08-10DOI: 10.1080/20442041.2023.2208515
Tao Huang, Yang Luo, Quanliang Jiang, Zhigang Zhang, Hao Yang, Changchun Huang
ABSTRACTThe concentration and sources of organic nitrogen (ON) in lake sediments affect lake nitrogen cycles. However, the factors influencing ON accumulation rate (ONAR) are unclear. We collected 3 sediment cores from northern, eastern, and southern Dianchi Lake (DC-N, DC-E, and DC-S, respectively) in July 2014, to study the effects of autochthonous and allochthonous sources of ON. The ON and ONAR increased 2.4–5.1 and 2.6–4.8 times, respectively, from 1900 to 2000, especially since the 1980s, when algal blooms have occurred more frequently. The ON decreased in the order DC-S > DC-N > DC-E, whereas the ONAR decreased in the order DC-N > DC-S > DC-E, suggesting that ONAR was influenced by ON content as well as the depositional environment. The total concentrations of n-alkanes (n-C12 to n-C34) ranged from 4719 to 61 960 ng g−1 in the 3 sediment cores, with proportions varying with vertical depth. The sources of ON were mainly allochthonous (soil erosion and terrestrial plants) and autochthonous (algal and aquatic plants) in DC-S and DC-N, respectively, and primarily mixed planktonic and terrestrial in DC-E. The stochastic impacts by regression on population, affluence, and technology (STIRPAT) model revealed that a 1% increase in air temperature and nitrogen fertilizer corresponded to an increase in ONAR by 23–33% and 20–79% in the Dianchi Lake basin, especially in DC-S and DC-E. However, a 1% increase in urban land area reduced ONAR by 2–11%, especially in DC-N. Our study suggests that the spatial and temporal ONAR in Dianchi Lake may increase in response to a warmer and wetter climate combined with increasing chemical nitrogen fertilizer application.KEYWORDS: algal bloomsDianchi Lakehuman activitiesn-alkanesorganic nitrogenSTIRPAT model AcknowledgementsWe thank Editage (www.editage.cn) for English language editing. We also sincerely thank the 2 anonymous reviewers and Associate Editor Dr. Grant Douglas for their constructive comments to improve the readability and scientific presentation of this manuscript.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was funded by the National Natural Science Foundation of China (Grant No. 41971009, 41503054, 41971286 and 41773097), and the Youth Top Talent funded by Nanjing Normal University.
{"title":"Synergistic impacts of climate change and human activities on spatiotemporal organic nitrogen burial variation in a plateau lake in southwest China","authors":"Tao Huang, Yang Luo, Quanliang Jiang, Zhigang Zhang, Hao Yang, Changchun Huang","doi":"10.1080/20442041.2023.2208515","DOIUrl":"https://doi.org/10.1080/20442041.2023.2208515","url":null,"abstract":"ABSTRACTThe concentration and sources of organic nitrogen (ON) in lake sediments affect lake nitrogen cycles. However, the factors influencing ON accumulation rate (ONAR) are unclear. We collected 3 sediment cores from northern, eastern, and southern Dianchi Lake (DC-N, DC-E, and DC-S, respectively) in July 2014, to study the effects of autochthonous and allochthonous sources of ON. The ON and ONAR increased 2.4–5.1 and 2.6–4.8 times, respectively, from 1900 to 2000, especially since the 1980s, when algal blooms have occurred more frequently. The ON decreased in the order DC-S > DC-N > DC-E, whereas the ONAR decreased in the order DC-N > DC-S > DC-E, suggesting that ONAR was influenced by ON content as well as the depositional environment. The total concentrations of n-alkanes (n-C12 to n-C34) ranged from 4719 to 61 960 ng g−1 in the 3 sediment cores, with proportions varying with vertical depth. The sources of ON were mainly allochthonous (soil erosion and terrestrial plants) and autochthonous (algal and aquatic plants) in DC-S and DC-N, respectively, and primarily mixed planktonic and terrestrial in DC-E. The stochastic impacts by regression on population, affluence, and technology (STIRPAT) model revealed that a 1% increase in air temperature and nitrogen fertilizer corresponded to an increase in ONAR by 23–33% and 20–79% in the Dianchi Lake basin, especially in DC-S and DC-E. However, a 1% increase in urban land area reduced ONAR by 2–11%, especially in DC-N. Our study suggests that the spatial and temporal ONAR in Dianchi Lake may increase in response to a warmer and wetter climate combined with increasing chemical nitrogen fertilizer application.KEYWORDS: algal bloomsDianchi Lakehuman activitiesn-alkanesorganic nitrogenSTIRPAT model AcknowledgementsWe thank Editage (www.editage.cn) for English language editing. We also sincerely thank the 2 anonymous reviewers and Associate Editor Dr. Grant Douglas for their constructive comments to improve the readability and scientific presentation of this manuscript.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was funded by the National Natural Science Foundation of China (Grant No. 41971009, 41503054, 41971286 and 41773097), and the Youth Top Talent funded by Nanjing Normal University.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135492963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-02DOI: 10.1080/20442041.2023.2242084
Fee-Nanett Trau, Kathrin Fisch, S. Lorenz
{"title":"Habitat type strongly influences the structural benthic invertebrate community composition in a landscape characterized by ubiquitous, long-term occurrences of agricultural stress","authors":"Fee-Nanett Trau, Kathrin Fisch, S. Lorenz","doi":"10.1080/20442041.2023.2242084","DOIUrl":"https://doi.org/10.1080/20442041.2023.2242084","url":null,"abstract":"","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45900017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-02DOI: 10.1080/20442041.2023.2242081
M. Thayne, Benjamin M. Kraemer, Jorrit P. Mesman, D. Pierson, A. Laas, E. de Eyto, B. Ibelings, R. Adrian
{"title":"Lake surface water temperature and oxygen saturation resistance and resilience following extreme storms: Chlorophyll a shapes resistance toward storms","authors":"M. Thayne, Benjamin M. Kraemer, Jorrit P. Mesman, D. Pierson, A. Laas, E. de Eyto, B. Ibelings, R. Adrian","doi":"10.1080/20442041.2023.2242081","DOIUrl":"https://doi.org/10.1080/20442041.2023.2242081","url":null,"abstract":"","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42147541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-06-09DOI: 10.1080/20442041.2023.2218985
T. Mehner
{"title":"Diversity of researcher types and plurality of philosophical concepts in limnology – an essay","authors":"T. Mehner","doi":"10.1080/20442041.2023.2218985","DOIUrl":"https://doi.org/10.1080/20442041.2023.2218985","url":null,"abstract":"","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47558975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-31DOI: 10.1080/20442041.2023.2218983
Chi-Feng Chen, Yang-Ming Chen, Jen-Yang Lin
ABSTRACT Eutrophication in freshwater lakes and reservoirs is a key threat to aquatic ecosystems and water supply systems. In some lakes and reservoirs, waterbirds might be an important nutrient source. The effects of waterbirds on water quality have been studied in temperate regions, but few studies have been conducted in tropical or subtropical regions. This study is the first to demonstrate the effects of migratory birds and cormorants on an Asian subtropical lake, Yangming Lake, Kinmen Island, Taiwan. Water quality model tools were applied with field investigations. During the study period, rainfall was relatively low and water storage was very low, resulting in cormorants contributing a high percentage of the phosphorus (P) loads, ∼70% of the annual external nutrients. However, when simulating normal rainfall records, the simulated total P (TP) concentration decreased, and the waterbirds contributed 55% of the external nutrients. Without the birds, the TP concentration is expected to be <50 μg/L under normal water volume. This study showed that migratory waterbird roosting could bring excess nutrients to the lake and significantly affect the water quality during the migratory period. However, the status of the lake water volume might dilute or strengthen the impacts of waterbirds. The random and nonlinear effects of waterbird droppings can be regarded as nonpoint source pollution, and management strategies are suggested to reduce the transport of waterbird droppings to receiving waterbodies.
{"title":"Assessing the effects of migratory waterbird droppings on potential lake eutrophication using water quality models: A case study of Yangming Lake on Kinmen Island, Taiwan.","authors":"Chi-Feng Chen, Yang-Ming Chen, Jen-Yang Lin","doi":"10.1080/20442041.2023.2218983","DOIUrl":"https://doi.org/10.1080/20442041.2023.2218983","url":null,"abstract":"ABSTRACT Eutrophication in freshwater lakes and reservoirs is a key threat to aquatic ecosystems and water supply systems. In some lakes and reservoirs, waterbirds might be an important nutrient source. The effects of waterbirds on water quality have been studied in temperate regions, but few studies have been conducted in tropical or subtropical regions. This study is the first to demonstrate the effects of migratory birds and cormorants on an Asian subtropical lake, Yangming Lake, Kinmen Island, Taiwan. Water quality model tools were applied with field investigations. During the study period, rainfall was relatively low and water storage was very low, resulting in cormorants contributing a high percentage of the phosphorus (P) loads, ∼70% of the annual external nutrients. However, when simulating normal rainfall records, the simulated total P (TP) concentration decreased, and the waterbirds contributed 55% of the external nutrients. Without the birds, the TP concentration is expected to be <50 μg/L under normal water volume. This study showed that migratory waterbird roosting could bring excess nutrients to the lake and significantly affect the water quality during the migratory period. However, the status of the lake water volume might dilute or strengthen the impacts of waterbirds. The random and nonlinear effects of waterbird droppings can be regarded as nonpoint source pollution, and management strategies are suggested to reduce the transport of waterbird droppings to receiving waterbodies.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47475752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-17DOI: 10.1080/20442041.2023.2213629
S. Zhai, P. Huang, J. Marshall, Jaye S. Lobegeiger, R. Cramp, M. A. Parisi, C. Franklin, Andrea Prior, Kamilla Kurucz, M. Hipsey
ABSTRACT Dryland river waterholes provide critical habitat and serve as refugia for aquatic animals during droughts, but the quality of these waterholes can often be severely compromised by hypoxic conditions that can lead to mass fish kills and loss of biodiversity. To assist river management, we developed a waterhole-scale ecohydrology model representing thermal stratification and dissolved oxygen regimes during prolonged drought periods in northern Murray-Darling Basin dryland rivers in Queensland, Australia. Model development focused around 6 typical waterholes in these rivers that were shallow (<5 m deep), highly turbid, and stratified with low dissolved oxygen. The model simulations utilised regional climate corrected for local factors such as diurnal vegetation shading and wind sheltering and successfully reproduced the prolonged stratification and hypoxia measured during drought conditions. The simulations highlight the distinct local climate each waterhole experiences due to the combined effects of river morphology and canopy cover that provide various degrees of solar shading and wind sheltering. The model can serve as a tool to inform water management decisions and climate adaptation strategies. Example scenarios demonstrate that (1) even where the canopy shading effect was small (5% at one site), further loss of riparian vegetation could increase temperature by 2–4 °C in warmer months with prolonged stratification; and (2) under an example RCP 8.5 climate change scenario, water temperature is likely to increase 2–10 °C, and oxygen saturation will decrease by 10% to 20% in the middle layers for most of the no-flow period by 2080–2099.
{"title":"Modelling prolonged stratification and hypoxia in dryland river waterholes during drought conditions","authors":"S. Zhai, P. Huang, J. Marshall, Jaye S. Lobegeiger, R. Cramp, M. A. Parisi, C. Franklin, Andrea Prior, Kamilla Kurucz, M. Hipsey","doi":"10.1080/20442041.2023.2213629","DOIUrl":"https://doi.org/10.1080/20442041.2023.2213629","url":null,"abstract":"ABSTRACT Dryland river waterholes provide critical habitat and serve as refugia for aquatic animals during droughts, but the quality of these waterholes can often be severely compromised by hypoxic conditions that can lead to mass fish kills and loss of biodiversity. To assist river management, we developed a waterhole-scale ecohydrology model representing thermal stratification and dissolved oxygen regimes during prolonged drought periods in northern Murray-Darling Basin dryland rivers in Queensland, Australia. Model development focused around 6 typical waterholes in these rivers that were shallow (<5 m deep), highly turbid, and stratified with low dissolved oxygen. The model simulations utilised regional climate corrected for local factors such as diurnal vegetation shading and wind sheltering and successfully reproduced the prolonged stratification and hypoxia measured during drought conditions. The simulations highlight the distinct local climate each waterhole experiences due to the combined effects of river morphology and canopy cover that provide various degrees of solar shading and wind sheltering. The model can serve as a tool to inform water management decisions and climate adaptation strategies. Example scenarios demonstrate that (1) even where the canopy shading effect was small (5% at one site), further loss of riparian vegetation could increase temperature by 2–4 °C in warmer months with prolonged stratification; and (2) under an example RCP 8.5 climate change scenario, water temperature is likely to increase 2–10 °C, and oxygen saturation will decrease by 10% to 20% in the middle layers for most of the no-flow period by 2080–2099.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48956079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-05-12DOI: 10.1080/20442041.2023.2213630
H. Fu, Jingjing Guo, Yili Ge, Aiping Wu, Wei Li, Huanyao Liu, Guixiang Yuan, E. Jeppesen
ABSTRACT Biological communities exhibit multiple distribution patterns at the metacommunity scale, and assessing the major drivers of these patterns is a key issue in community ecology. Here we investigated how the environmental and geographic gradients shape the distribution patterns of macrophytes at the metacommunity level. We applied the framework of the elements of the metacommunity structure (EMS) to identify the distinct types of 48 macrophyte metacommunities in the Hengduan Mountain region (HDMR) of China. We then used a generalized linear model and model selection approaches to determine which variables contributed to the variations of EMS and linear discriminant function analysis to evaluate how well the tested variables predicted metacommunity patterns. We found wide variations in the 3 EMS (i.e., coherence, range turnover, and range boundary clumping): latitude and alpha diversity were most important in determining coherence; nestedness was mostly related to turnover; and sampling depth was significantly associated with boundary clumping. Seven metacommunity types were identified in HDMR, and most metacommunities best fitted the Gleasonian and Clementsian patterns as well as their quasi-structures. Notably, Gleasonian and Q-Gleasonian patterns as well as the other 3 patterns (i.e., Q-nested, evenly spaced, and nested) were for the first time detected for macrophytes. These metacommunity types were best discriminated by nestedness, altitude, and latitude. Our results provide strong evidence of the impact of geographic patterns on macrophyte metacommunities, with the Gleasonian patterns dominant at both ends of the latitude/altitude gradient and Clementsian patterns common near the central part of the gradient.
{"title":"Ecogeographic patterns of macrophyte metacommunities in the Hengduan Mountain Region","authors":"H. Fu, Jingjing Guo, Yili Ge, Aiping Wu, Wei Li, Huanyao Liu, Guixiang Yuan, E. Jeppesen","doi":"10.1080/20442041.2023.2213630","DOIUrl":"https://doi.org/10.1080/20442041.2023.2213630","url":null,"abstract":"ABSTRACT Biological communities exhibit multiple distribution patterns at the metacommunity scale, and assessing the major drivers of these patterns is a key issue in community ecology. Here we investigated how the environmental and geographic gradients shape the distribution patterns of macrophytes at the metacommunity level. We applied the framework of the elements of the metacommunity structure (EMS) to identify the distinct types of 48 macrophyte metacommunities in the Hengduan Mountain region (HDMR) of China. We then used a generalized linear model and model selection approaches to determine which variables contributed to the variations of EMS and linear discriminant function analysis to evaluate how well the tested variables predicted metacommunity patterns. We found wide variations in the 3 EMS (i.e., coherence, range turnover, and range boundary clumping): latitude and alpha diversity were most important in determining coherence; nestedness was mostly related to turnover; and sampling depth was significantly associated with boundary clumping. Seven metacommunity types were identified in HDMR, and most metacommunities best fitted the Gleasonian and Clementsian patterns as well as their quasi-structures. Notably, Gleasonian and Q-Gleasonian patterns as well as the other 3 patterns (i.e., Q-nested, evenly spaced, and nested) were for the first time detected for macrophytes. These metacommunity types were best discriminated by nestedness, altitude, and latitude. Our results provide strong evidence of the impact of geographic patterns on macrophyte metacommunities, with the Gleasonian patterns dominant at both ends of the latitude/altitude gradient and Clementsian patterns common near the central part of the gradient.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44230837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-20DOI: 10.1080/20442041.2023.2204050
M. Burford, Anusuya Willis, Man Xiao, M. Prentice, David P. Hamilton
{"title":"Understanding the relationship between nutrient availability and freshwater cyanobacterial growth and abundance","authors":"M. Burford, Anusuya Willis, Man Xiao, M. Prentice, David P. Hamilton","doi":"10.1080/20442041.2023.2204050","DOIUrl":"https://doi.org/10.1080/20442041.2023.2204050","url":null,"abstract":"","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44738550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-17DOI: 10.1080/20442041.2023.2203060
M. Søndergaard, Anders Nielsen, L. Johansson, T. Davidson
ABSTRACT Lakes that undergo temporary stratification in summer do not fit into the classic categorisation of polymictic or dimictic lakes, but how common are they and what are the effects of stratification on the development of anoxia? We used monthly and bimonthly (twice per month) temperature and oxygen profile data from 436 Danish lakes (area range 1–3954 ha, maximum depth range 1.3–45 m) and defined a stratification indicator based on the temperature difference between the upper and lower 2 m of the water column. The stratification indicator had values between −1.6 and 17.7 °C and was significantly and strongly related to lake maximum depth and significantly but less strongly related to lake area. The indicator was highly variable, especially in lakes with maximum depths between 4 and 10 m, where intermediate indicator values suggest one or several mixing events during summer. The dissolved oxygen concentration in summer at the bottom was often <1 mg/L, even when the difference between top and bottom temperature was as low as 0.5–1.0 °C. Temporarily stratifying lakes with frequent mixing events over the summer are probably common in temperate lowland areas but are easily overlooked in routine monitoring programs. Temporary stratification has pronounced implications for the oxygen concentrations and potentially also for the biota and interactions between sediment and water.
{"title":"Temporarily summer-stratified lakes are common: profile data from 436 lakes in lowland Denmark","authors":"M. Søndergaard, Anders Nielsen, L. Johansson, T. Davidson","doi":"10.1080/20442041.2023.2203060","DOIUrl":"https://doi.org/10.1080/20442041.2023.2203060","url":null,"abstract":"ABSTRACT Lakes that undergo temporary stratification in summer do not fit into the classic categorisation of polymictic or dimictic lakes, but how common are they and what are the effects of stratification on the development of anoxia? We used monthly and bimonthly (twice per month) temperature and oxygen profile data from 436 Danish lakes (area range 1–3954 ha, maximum depth range 1.3–45 m) and defined a stratification indicator based on the temperature difference between the upper and lower 2 m of the water column. The stratification indicator had values between −1.6 and 17.7 °C and was significantly and strongly related to lake maximum depth and significantly but less strongly related to lake area. The indicator was highly variable, especially in lakes with maximum depths between 4 and 10 m, where intermediate indicator values suggest one or several mixing events during summer. The dissolved oxygen concentration in summer at the bottom was often <1 mg/L, even when the difference between top and bottom temperature was as low as 0.5–1.0 °C. Temporarily stratifying lakes with frequent mixing events over the summer are probably common in temperate lowland areas but are easily overlooked in routine monitoring programs. Temporary stratification has pronounced implications for the oxygen concentrations and potentially also for the biota and interactions between sediment and water.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44802534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-12DOI: 10.1080/20442041.2023.2201395
Tiphaine Labed-Veydert, A. Bec, M. Danger, F. Perrière, C. Desvilettes
ABSTRACT Headwater streams are characterised by predominantly heterotrophic functioning resulting from leaf litter input, but autochthonous primary production can also contribute to energy fluxes and the supply of nutrients. While much work has focused on the role of polyunsaturated fatty acids as essential nutrients, less attention has been paid to the significance of sterols in stream food webs. Yet these molecules are essential to arthropods that can only synthesise cholesterol from a limited range of dietary sterols. In a headwater stream, we tracked the transfer of dominant sterols from allochthonous and autochthonous resources to 5 benthic macroinvertebrates. Despite their formal functional feeding group, all the taxa tended to be opportunistic omnivores that relied on all available resources. These behaviours could be attributed to nutritional constraints in the stream food web, but these constraints were not related to the sterol supply from the different basal sources. Dominant sterols from detrital sources (leaf litter, fine benthic organic matter [FBOM]) and primary producers (epilithic biofilms, bryophytes) were all Δ5-sterols (β-sitosterol, campesterol, stigmasterol, epibrassicasterol). The levels of cholesterol detected in macroinvertebrates, as well as the presence of desmosterol, indicate efficient dealkylation activity of these Δ5-sterols. Leaf litter has consistently shown high β-sitosterol/stigmasterol ratios, giving it greater nutritional value than usually accepted. But bryophytes, and especially epilithic biofilms, contained cholesterol, providing a direct supply to invertebrates, thereby promoting their growth. Detrital particles (FBOM) colonised by microalgae could be the best-balanced diet to avoid sterol deficiencies due to their cholesterol content and high β-sitosterol/stigmasterol ratios.
{"title":"Does sterol availability in a forested headwater stream constitute a nutritional constraint for macroinvertebrates?","authors":"Tiphaine Labed-Veydert, A. Bec, M. Danger, F. Perrière, C. Desvilettes","doi":"10.1080/20442041.2023.2201395","DOIUrl":"https://doi.org/10.1080/20442041.2023.2201395","url":null,"abstract":"ABSTRACT Headwater streams are characterised by predominantly heterotrophic functioning resulting from leaf litter input, but autochthonous primary production can also contribute to energy fluxes and the supply of nutrients. While much work has focused on the role of polyunsaturated fatty acids as essential nutrients, less attention has been paid to the significance of sterols in stream food webs. Yet these molecules are essential to arthropods that can only synthesise cholesterol from a limited range of dietary sterols. In a headwater stream, we tracked the transfer of dominant sterols from allochthonous and autochthonous resources to 5 benthic macroinvertebrates. Despite their formal functional feeding group, all the taxa tended to be opportunistic omnivores that relied on all available resources. These behaviours could be attributed to nutritional constraints in the stream food web, but these constraints were not related to the sterol supply from the different basal sources. Dominant sterols from detrital sources (leaf litter, fine benthic organic matter [FBOM]) and primary producers (epilithic biofilms, bryophytes) were all Δ5-sterols (β-sitosterol, campesterol, stigmasterol, epibrassicasterol). The levels of cholesterol detected in macroinvertebrates, as well as the presence of desmosterol, indicate efficient dealkylation activity of these Δ5-sterols. Leaf litter has consistently shown high β-sitosterol/stigmasterol ratios, giving it greater nutritional value than usually accepted. But bryophytes, and especially epilithic biofilms, contained cholesterol, providing a direct supply to invertebrates, thereby promoting their growth. Detrital particles (FBOM) colonised by microalgae could be the best-balanced diet to avoid sterol deficiencies due to their cholesterol content and high β-sitosterol/stigmasterol ratios.","PeriodicalId":49061,"journal":{"name":"Inland Waters","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44448443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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