Pub Date : 2023-12-21DOI: 10.4081/jlimnol.2023.2159
G. I. Manetta, Matheus Maximilian Ratz Scoarize, Driele Delanira-Santos, P. A. Sacramento, V. D. A. Urbano, E. Benedito
The trophic discrimination factor (TDF) is a key parameter for stable isotope analysis and due to a lack of species-specific TDFs, mean universal values have been used, resulting in uncertainties about the trophic position of species and a call for more experiments. In this study, we have addressed the lack of experimental species-specific TDFs conducting three experiments of 128 days each to determine the TDF (muscle and liver) of three species, the piscivore Pseudoplatystoma corruscans (Spix & Agassiz, 1829), and the omnivores Piaractus mesopotamicus (Holmberg, 1887) and Astyanax lacustris (Lütken, 1875), tropical fishes native to the La Plata River basin. Then, we calculated the trophic position (TP) using the mean universal TDF from literature and the species-specific TDF produced in this study for Pseudoplatystoma corruscans. We estimated the TDFs for the three species through experiment and the values found differed from the mean universal TDF in the literature. Moreover, the TP was lower when using the species-specific TDFs. The TP is important for several analyses, including its use in functional diversity. Therefore, we recommend using species-specific TDF values for calculating TP once it differs from the results calculated with mean universal TDF.
{"title":"Diet-tissue discrimination factors of three neotropical freshwater fishes and a comparison of the trophic position","authors":"G. I. Manetta, Matheus Maximilian Ratz Scoarize, Driele Delanira-Santos, P. A. Sacramento, V. D. A. Urbano, E. Benedito","doi":"10.4081/jlimnol.2023.2159","DOIUrl":"https://doi.org/10.4081/jlimnol.2023.2159","url":null,"abstract":"The trophic discrimination factor (TDF) is a key parameter for stable isotope analysis and due to a lack of species-specific TDFs, mean universal values have been used, resulting in uncertainties about the trophic position of species and a call for more experiments. In this study, we have addressed the lack of experimental species-specific TDFs conducting three experiments of 128 days each to determine the TDF (muscle and liver) of three species, the piscivore Pseudoplatystoma corruscans (Spix & Agassiz, 1829), and the omnivores Piaractus mesopotamicus (Holmberg, 1887) and Astyanax lacustris (Lütken, 1875), tropical fishes native to the La Plata River basin. Then, we calculated the trophic position (TP) using the mean universal TDF from literature and the species-specific TDF produced in this study for Pseudoplatystoma corruscans. We estimated the TDFs for the three species through experiment and the values found differed from the mean universal TDF in the literature. Moreover, the TP was lower when using the species-specific TDFs. The TP is important for several analyses, including its use in functional diversity. Therefore, we recommend using species-specific TDF values for calculating TP once it differs from the results calculated with mean universal TDF.","PeriodicalId":50164,"journal":{"name":"Journal of Limnology","volume":"39 11","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138948780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-12-13DOI: 10.4081/jlimnol.2023.2153
Melaku Getachew, S. T. Mereta, Geremew Sahlu Gebrie, W. Mulat, Mary Kelly-Quinne
The Koka hydropower dam is one of the oldest large dams in Ethiopia. Damming is one of the anthropogenic activities impacting the distribution of aquatic life forms. However, to date, little attention has been focused on the dam’s impacts on the river macroinvertebrate assemblages in Ethiopia. The objective of this study was, therefore, to assess the impacts of the Koka hydropower dam on macroinvertebrate assemblages in the Awash River basin in Ethiopia. In the three river reaches on the Awash River (upstream near the source of the river, midstream above the dam, and downstream below the dam), a total of 15 sites were selected for sampling. The statistical analysis tested the null hypothesis that there are no differences in macroinvertebrate assemblage patterns or a range of univariate metrics between the three river reaches. Additional analyses involved the identification of taxa responsible for significant differences in macroinvertebrate structure (e.g., percentage similarity) and an exploration of the variables that structure macroinvertebrates (e.g., canonical correspondence analysis). In the upstream, midstream, and downstream reaches of the Awash River, we recorded a total of 73 taxa belonging to 43 families and 12 orders. Trichoptera was the dominant order in the upstream river reach, whereas Diptera dominated the midstream and downstream river reaches. The diversity of macroinvertebrates decreased from upstream to midstream and downstream. The three river reaches differed significantly in Shannon and Simpson diversity indices, % EPT, EPT taxa abundance, total taxa richness, evenness index, % collectors, and % scrapers. In this study, we observed that macroinvertebrate assemblage differences and spatial patterns were significantly associated with values of river flow changes (velocity), phosphate concentration, and substrate index. The findings of this study have broad implications for the assessment of the impacts of dam construction on the rivers of the studied region in the future.
{"title":"Impacts of the Koka hydropower dam on macroinvertebrate assemblages in the Awash River Basin in Ethiopia","authors":"Melaku Getachew, S. T. Mereta, Geremew Sahlu Gebrie, W. Mulat, Mary Kelly-Quinne","doi":"10.4081/jlimnol.2023.2153","DOIUrl":"https://doi.org/10.4081/jlimnol.2023.2153","url":null,"abstract":"The Koka hydropower dam is one of the oldest large dams in Ethiopia. Damming is one of the anthropogenic activities impacting the distribution of aquatic life forms. However, to date, little attention has been focused on the dam’s impacts on the river macroinvertebrate assemblages in Ethiopia. The objective of this study was, therefore, to assess the impacts of the Koka hydropower dam on macroinvertebrate assemblages in the Awash River basin in Ethiopia. In the three river reaches on the Awash River (upstream near the source of the river, midstream above the dam, and downstream below the dam), a total of 15 sites were selected for sampling. The statistical analysis tested the null hypothesis that there are no differences in macroinvertebrate assemblage patterns or a range of univariate metrics between the three river reaches. Additional analyses involved the identification of taxa responsible for significant differences in macroinvertebrate structure (e.g., percentage similarity) and an exploration of the variables that structure macroinvertebrates (e.g., canonical correspondence analysis). In the upstream, midstream, and downstream reaches of the Awash River, we recorded a total of 73 taxa belonging to 43 families and 12 orders. Trichoptera was the dominant order in the upstream river reach, whereas Diptera dominated the midstream and downstream river reaches. The diversity of macroinvertebrates decreased from upstream to midstream and downstream. The three river reaches differed significantly in Shannon and Simpson diversity indices, % EPT, EPT taxa abundance, total taxa richness, evenness index, % collectors, and % scrapers. In this study, we observed that macroinvertebrate assemblage differences and spatial patterns were significantly associated with values of river flow changes (velocity), phosphate concentration, and substrate index. The findings of this study have broad implications for the assessment of the impacts of dam construction on the rivers of the studied region in the future.","PeriodicalId":50164,"journal":{"name":"Journal of Limnology","volume":"12 9","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139004953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-11-23DOI: 10.4081/jlimnol.2022.2168
Gayane Shahnazaryan, Martin Schultze, Karsten Rinke, B. Gabrielyan
Lake Sevan, a large, deep, alpine lake in the Lesser Caucasus is the focus of this Special Issue of the Journal of Limnology. It was an outstanding ecosystem 100 years ago characterised by excellent water quality, rich biodiversity with a high level of endemism, wide-ranging beds of macrophytes along the shores and a productive and sustainable fish production. Due to its beauty, natural history, and contributions to social and economic welfare it is also a cultural heritage for the Armenian Nation including its large diaspora.
{"title":"Lake Sevan. Past, present, and future state of a unique alpine lake","authors":"Gayane Shahnazaryan, Martin Schultze, Karsten Rinke, B. Gabrielyan","doi":"10.4081/jlimnol.2022.2168","DOIUrl":"https://doi.org/10.4081/jlimnol.2022.2168","url":null,"abstract":"Lake Sevan, a large, deep, alpine lake in the Lesser Caucasus is the focus of this Special Issue of the Journal of Limnology. It was an outstanding ecosystem 100 years ago characterised by excellent water quality, rich biodiversity with a high level of endemism, wide-ranging beds of macrophytes along the shores and a productive and sustainable fish production. Due to its beauty, natural history, and contributions to social and economic welfare it is also a cultural heritage for the Armenian Nation including its large diaspora.","PeriodicalId":50164,"journal":{"name":"Journal of Limnology","volume":"49 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139243299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-11-23DOI: 10.4081/jlimnol.2022.2150
A. Hayrapetyan, Gor A. Gevorgyan, Martin Schultze, Muhammed Shikhani, T. Khachikyan, Aleksandr Krylov, Karsten Rinke
We studied the quantitative composition, spatial distribution, and temporal dynamics of the zooplankton community of the alpine Lake Sevan, Armenia, the largest surface water in the Caucasus region. This article is providing a long-term information and fills the research gap of multiyear data on zooplankton, as the previous research on zooplankton provided only snapshots of the community, and a consistent assessment over multiple years was missing. However, an initial mini-review of historical studies indicated that zooplankton biomass and fish abundance were undergoing large fluctuations, indicating the importance of top-down control. We analysed 239 samples from the period 2016-2019 from 32 sampling sites in Lake Sevan and recorded 37 species of meso- and macrozooplankton (Rotifers, Copepods, Cladocera). Biomass fluctuations were high with peaking biomasses in 2016 and lowest biomasses in 2018, yearly averaged biomass varied about one order of magnitude. Variability over time was hence much higher than spatial variability. The pelagic habitat at the deepest part of the lake showed the highest diversity and biomasses but contrasts between sampling sites remained smaller than changes from year to year or seasonally. Many samples were dominated by a single species, and these key species explain observed biomass dynamics to a wide extent. We applied hierarchical clustering in order to identify phenological groups that appear to show similar patterns of occurrence. This clustering resulted in 6 groups where of 5 groups just consisting of one single species and these 5 key species were the Cladocerans Daphnia magna, Daphnia hyalina, Diaphanosoma sp. as well as the calanoids Arctodiaptomus bacillifer and Acanthodiaptomus denticornis. The most important species in Lake Sevan’s zooplankton during the observation period was D. magna, which reached high biomasses in 2016 and 2017 but then suddenly almost disappeared in 2018 and 2019. When there were more D. magna present, the water became clearer, which was measured using Secchi depth. This shows that these large water fleas effectively controlled the amount of phytoplankton in the water. Daphnia magna, in turn, managed to dominate zooplankton community only during times of extremely low fish biomass indicating strong top-down control of this large Cladoceran by fish. Both observations together imply a strong trophic linkage between fish, zooplankton, and phytoplankton and provide evidence for trophic cascades in Lake Sevan. Besides the novel insights into zooplankton community dynamics of this unique lake of high socio-economical, cultural, and ecological importance, our study also points to potential management opportunities for eutrophication control by biomanipulation, as well as our investigation allows us to conclude that probably biotic factors were more important than abiotic factors in explaining the observed changes and dynamics within the plankton community.
{"title":"Contemporary community composition, spatial distribution patterns, and biodiversity characteristics of zooplankton in large alpine Lake Sevan, Armenia","authors":"A. Hayrapetyan, Gor A. Gevorgyan, Martin Schultze, Muhammed Shikhani, T. Khachikyan, Aleksandr Krylov, Karsten Rinke","doi":"10.4081/jlimnol.2022.2150","DOIUrl":"https://doi.org/10.4081/jlimnol.2022.2150","url":null,"abstract":"We studied the quantitative composition, spatial distribution, and temporal dynamics of the zooplankton community of the alpine Lake Sevan, Armenia, the largest surface water in the Caucasus region. This article is providing a long-term information and fills the research gap of multiyear data on zooplankton, as the previous research on zooplankton provided only snapshots of the community, and a consistent assessment over multiple years was missing. However, an initial mini-review of historical studies indicated that zooplankton biomass and fish abundance were undergoing large fluctuations, indicating the importance of top-down control. We analysed 239 samples from the period 2016-2019 from 32 sampling sites in Lake Sevan and recorded 37 species of meso- and macrozooplankton (Rotifers, Copepods, Cladocera). Biomass fluctuations were high with peaking biomasses in 2016 and lowest biomasses in 2018, yearly averaged biomass varied about one order of magnitude. Variability over time was hence much higher than spatial variability. The pelagic habitat at the deepest part of the lake showed the highest diversity and biomasses but contrasts between sampling sites remained smaller than changes from year to year or seasonally. Many samples were dominated by a single species, and these key species explain observed biomass dynamics to a wide extent. We applied hierarchical clustering in order to identify phenological groups that appear to show similar patterns of occurrence. This clustering resulted in 6 groups where of 5 groups just consisting of one single species and these 5 key species were the Cladocerans Daphnia magna, Daphnia hyalina, Diaphanosoma sp. as well as the calanoids Arctodiaptomus bacillifer and Acanthodiaptomus denticornis. The most important species in Lake Sevan’s zooplankton during the observation period was D. magna, which reached high biomasses in 2016 and 2017 but then suddenly almost disappeared in 2018 and 2019. When there were more D. magna present, the water became clearer, which was measured using Secchi depth. This shows that these large water fleas effectively controlled the amount of phytoplankton in the water. Daphnia magna, in turn, managed to dominate zooplankton community only during times of extremely low fish biomass indicating strong top-down control of this large Cladoceran by fish. Both observations together imply a strong trophic linkage between fish, zooplankton, and phytoplankton and provide evidence for trophic cascades in Lake Sevan. Besides the novel insights into zooplankton community dynamics of this unique lake of high socio-economical, cultural, and ecological importance, our study also points to potential management opportunities for eutrophication control by biomanipulation, as well as our investigation allows us to conclude that probably biotic factors were more important than abiotic factors in explaining the observed changes and dynamics within the plankton community.","PeriodicalId":50164,"journal":{"name":"Journal of Limnology","volume":"73 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139242457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-11-20DOI: 10.4081/jlimnol.2023.2144
L. Hinegk, L. Adami, S. Piccolroaz, Marina Amadori, Marcello Moretti, Marco Tubino, M. Toffolon
Lake Garda, the largest in Italy, is a major source of water supply inserted in a trans-regional area, sustaining an ever-increasing variety of water interests since the XX century. We perform a multidecadal (1928-2020) water balance, estimating the long-term evolution of the input and output components under changing anthropogenic and climatic stressors. First, we present our hydrometeorological database, assembled through a consistent effort of collection and digitization of data from different sources. Then, we analyse the annual water balance, assessing the magnitude of the residual term, i.e. the unknown term that embeds uncertainties and potential sources of error, closing the water balance equation. Uncertainties are investigated by applying a multi-method analysis for over-lake evaporation and basin evapotranspiration. Land use evolution, contributions from the Mount Baldo area as well as the potential role of groundwater fluxes are additionally analysed. Eventually, we compute a sensitivity analysis to delineate the role of each component on the lake’s level and outflow variations. The long-term analysis allows for distinguishing some trends in the input and output components of the water balance. Differences emerge in the periods before and after the lake’s impoundment (1951), and some effects of climate modifications appear in the last decades. Precipitation over the basin has a major influence on the water availability within the basin, a result confirmed by the sensitivity analysis. The entity of the residual term, which represents the unaccounted contributions, calls into question the role of the groundwater fluxes and the time scale of the analysis. The multi-method analysis highlights the dependency of the different lake evaporation and basin evapotranspiration methods on the amount of data available.
{"title":"Multidecadal analysis of Lake Garda water balance","authors":"L. Hinegk, L. Adami, S. Piccolroaz, Marina Amadori, Marcello Moretti, Marco Tubino, M. Toffolon","doi":"10.4081/jlimnol.2023.2144","DOIUrl":"https://doi.org/10.4081/jlimnol.2023.2144","url":null,"abstract":"Lake Garda, the largest in Italy, is a major source of water supply inserted in a trans-regional area, sustaining an ever-increasing variety of water interests since the XX century. We perform a multidecadal (1928-2020) water balance, estimating the long-term evolution of the input and output components under changing anthropogenic and climatic stressors. First, we present our hydrometeorological database, assembled through a consistent effort of collection and digitization of data from different sources. Then, we analyse the annual water balance, assessing the magnitude of the residual term, i.e. the unknown term that embeds uncertainties and potential sources of error, closing the water balance equation. Uncertainties are investigated by applying a multi-method analysis for over-lake evaporation and basin evapotranspiration. Land use evolution, contributions from the Mount Baldo area as well as the potential role of groundwater fluxes are additionally analysed. Eventually, we compute a sensitivity analysis to delineate the role of each component on the lake’s level and outflow variations. The long-term analysis allows for distinguishing some trends in the input and output components of the water balance. Differences emerge in the periods before and after the lake’s impoundment (1951), and some effects of climate modifications appear in the last decades. Precipitation over the basin has a major influence on the water availability within the basin, a result confirmed by the sensitivity analysis. The entity of the residual term, which represents the unaccounted contributions, calls into question the role of the groundwater fluxes and the time scale of the analysis. The multi-method analysis highlights the dependency of the different lake evaporation and basin evapotranspiration methods on the amount of data available.","PeriodicalId":50164,"journal":{"name":"Journal of Limnology","volume":"127 3","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139256746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
Atribacteria play an important role in global carbon cycling. Little is known, however, about the Atribacteria communities found inalpine lakes. The presence and diversity of Atribacteria in the sediment core of alpine Sayram lake in China were investigated usingIllumina MiSeq sequencing in this study. According to the findings, Atribacteria affiliated with JS1 were dominant in the sediment coreof Sayram Lake, with a relative abundance of 0.19 to 10% (average 3.75%) of all bacterial sequences. Furthermore, the relativeabundance of Atribacteria associated with JS1 increased with sediment depth. As a result, this study significantly contributes to ourunderstanding of Atribacteria community habitat.
{"title":"The prevalence of Atribacteria affiliated with JS1 in the sediment core of Lake Sayram, the largest alpine lake, China","authors":"Keqiang Shao, Tunasheng Ba, Boqiang Qin, Jianying Chao, Guang Gao","doi":"10.4081/jlimnol.2023.2152","DOIUrl":"https://doi.org/10.4081/jlimnol.2023.2152","url":null,"abstract":"Atribacteria play an important role in global carbon cycling. Little is known, however, about the Atribacteria communities found inalpine lakes. The presence and diversity of Atribacteria in the sediment core of alpine Sayram lake in China were investigated usingIllumina MiSeq sequencing in this study. According to the findings, Atribacteria affiliated with JS1 were dominant in the sediment coreof Sayram Lake, with a relative abundance of 0.19 to 10% (average 3.75%) of all bacterial sequences. Furthermore, the relativeabundance of Atribacteria associated with JS1 increased with sediment depth. As a result, this study significantly contributes to ourunderstanding of Atribacteria community habitat.","PeriodicalId":50164,"journal":{"name":"Journal of Limnology","volume":"96 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139258714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-11-20DOI: 10.4081/jlimnol.2023.2151
Aldo Marchetto, S. Musazzi
We propose a procedure to update ecological quality indices using species autoecology estimated by gradient analysis when new species are found, or taxonomy is updated. When updating an index, the new values must be comparable to the old ones to avoid recalibration and quality class boundary changes. As gradient length influences the values of the species optima, we propose to avoid adding new species to existing lists and we suggest recalibrating the index with a new calibration dataset and rescaling species optima. This final step reduces index updating-induced quality classification changes. An example is shown using the EPI-L diatom index, a quality index for lakes affected by trophic pressure.
{"title":"A procedure to update quality indices based on species abundances: an example using the EPI-L diatom index","authors":"Aldo Marchetto, S. Musazzi","doi":"10.4081/jlimnol.2023.2151","DOIUrl":"https://doi.org/10.4081/jlimnol.2023.2151","url":null,"abstract":"We propose a procedure to update ecological quality indices using species autoecology estimated by gradient analysis when new species are found, or taxonomy is updated. When updating an index, the new values must be comparable to the old ones to avoid recalibration and quality class boundary changes. As gradient length influences the values of the species optima, we propose to avoid adding new species to existing lists and we suggest recalibrating the index with a new calibration dataset and rescaling species optima. This final step reduces index updating-induced quality classification changes. An example is shown using the EPI-L diatom index, a quality index for lakes affected by trophic pressure.","PeriodicalId":50164,"journal":{"name":"Journal of Limnology","volume":"44 5","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139255213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-11-13DOI: 10.4081/jlimnol.2022.2143
Lisa Elzi, Edoardo Villa, Nicola Patocchi
The present study investigates the impact of water level regulation on the growth of common reed (Phragmites australis), a globally widespread helophytic plant. The investigation has been carried out in the Bolle di Magadino (municipalities of Locarno, Gambarogno, Gordola and Tenero; Ticino, Switzerland), a lacustrine-riparian nature reserve in the context of the Lake Maggiore (that stretches between Italy and Switzerland). This is an oligotrophic, artificially regulated lake. Our initial hypothesis was that variation in water table regulation is the most influential factor for explaining observed local reed dieback. To test this, culm height of P. australis was measured at each significant change in lake water level (water table height increase greater than 20 cm), or monthly in the case of a relatively constant lake level. The study took place between 2020 and 2022, monitoring 14 plots of 400 m2, placed at three different relative elevation classes with respect to the level of the lake (5 plots at low elevation, <193.475 m; 7 plots at intermediate elevation, 193.476-193.700 m; 2 plots at high elevation, >193.701 m). The results showed that P. australis growth is significantly influenced by the lake water level and thus the relative elevation of the stands, with lower lake levels leading to better growth, especially during the early phases of the growing season. On the other hand, prolonged flooding of shoots significantly impaired common reed growth. The study identifies two relevant relative elevation thresholds for winter mowing, a management practice that enhances reedbeds health. Mowing below 193.20 m elevation is considered risky, as no healthy reedbeds have been observed below this threshold. Mowing below an elevation of 193.50 m was defined as possibly risky, due to observed dieback in some areas as well as healthy reedbeds in other locations at the same or lower elevations. The research also discussed the potential impact of future changes in water level regulation, including the planned change in the spring regulation threshold (+1.50 m above the hydrometric zero in Sesto Calende). This is expected to result in a further rearrangement in lacustrine vegetation, with the growth optimum for P. australis becoming higher and an increase in clumping habit. In conclusion, this study provides valuable insights into the impact of water level regulation on the growth of P. australis in the Bolle di Magadino nature reserve. The research highlights the need for careful management of water level regulation to preserve the reedbed ecosystem and identifies relevant elevation thresholds for winter mowing to mitigate the risks of reed dieback. The findings can inform future management strategies for the Bolle di Magadino reserve and other similar ecosystems facing the challenges of artificial regulation of water levels.
本研究调查了水位调节对普通芦苇（Phragmites australis）生长的影响，普通芦苇是一种全球广泛分布的轮叶植物。调查在 Bolle di Magadino（瑞士提契诺州洛迦诺市、甘巴尔戈诺市、戈尔多拉市和特内罗市）进行，该自然保护区是马焦雷湖（位于意大利和瑞士之间）范围内的一个湖沼自然保护区。这是一个人工调节的低营养湖。我们最初的假设是，地下水位调节的变化是解释观察到的当地芦苇枯死的最有影响力的因素。为了验证这一假设，我们在湖泊水位每次发生显著变化（水位上升超过 20 厘米）时测量芦苇的茎秆高度，如果湖泊水位相对稳定，则每月测量一次。研究在 2020 年至 2022 年期间进行，共监测了 14 块 400 平方米的地块，分别位于相对于湖面的三个不同相对高度等级（5 块位于低海拔，193.701 米）。结果表明，湖泊水位以及湖泊的相对高度对澳洲鹅掌楸（P. australis）的生长有很大影响，湖泊水位越低，生长越好，尤其是在生长季节的早期阶段。另一方面，嫩芽长期受淹会严重影响芦苇的生长。该研究确定了冬季除草的两个相关相对高度阈值，这是一种可提高芦苇健康水平的管理方法。在海拔 193.20 米以下进行除草被认为是有风险的，因为在此阈值以下未观察到健康的芦苇丛。海拔 193.50 米以下的刈割被定义为可能存在风险，因为在一些地区观察到了枯死现象，而在海拔相同或更低的其他地点也发现了健康的芦苇丛。研究还讨论了未来水位调节变化的潜在影响，包括计划中的春季调节阈值变化（Sesto Calende 水位零点以上+1.50 米）。预计这将导致湖泊植被的进一步重新安排，使 P. australis 的最适生长区变得更高，并增加丛生习性。总之，这项研究为了解水位调节对 Bolle di Magadino 自然保护区内澳洲鹅掌楸生长的影响提供了宝贵的见解。研究强调了谨慎管理水位调节以保护芦苇生态系统的必要性，并确定了冬季除草的相关海拔阈值，以降低芦苇枯死的风险。研究结果可为 Bolle di Magadino 保护区以及其他面临人工调节水位挑战的类似生态系统提供未来管理策略的参考。
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Pub Date : 2023-11-13DOI: 10.4081/jlimnol.2022.2166
A. Boggero, M. Rogora, S. Quadroni
The Interreg “Parks Verbano Ticino” (PVT) project was conceived within the technical committee dedicated to the “Experimentation of the regulation of the Lake Maggiore levels” following the requests of the water manager to raise the spring-summer maximum levels of the lake compared to the levels normally held in the same period to respond to the industrial, agricultural, touristic, and environmental needs...
{"title":"Effects of water level management on lake littorals and downstream river areas","authors":"A. Boggero, M. Rogora, S. Quadroni","doi":"10.4081/jlimnol.2022.2166","DOIUrl":"https://doi.org/10.4081/jlimnol.2022.2166","url":null,"abstract":"The Interreg “Parks Verbano Ticino” (PVT) project was conceived within the technical committee dedicated to the “Experimentation of the regulation of the Lake Maggiore levels” following the requests of the water manager to raise the spring-summer maximum levels of the lake compared to the levels normally held in the same period to respond to the industrial, agricultural, touristic, and environmental needs...","PeriodicalId":50164,"journal":{"name":"Journal of Limnology","volume":"192 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139278592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-11-09DOI: 10.4081/jlimnol.2023.2169
Piero Guilizzoni
In memoriam of Prof. Giuliano Bonomi
纪念朱利亚诺-博诺米教授
{"title":"In memoriam of Prof. Giuliano Bonomi (1933-2023)","authors":"Piero Guilizzoni","doi":"10.4081/jlimnol.2023.2169","DOIUrl":"https://doi.org/10.4081/jlimnol.2023.2169","url":null,"abstract":"In memoriam of Prof. Giuliano Bonomi","PeriodicalId":50164,"journal":{"name":"Journal of Limnology","volume":"39 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139281720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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