L. King, J. Brahney, Scott Daly, M. Paul, Kateri R. Salk, S. Brothers
Benthic primary production (BPP) plays an important functional role in lakes, improving water quality by stabilizing clear-water regimes. Shallow, eutrophic lakes lacking BPP communities can be difficult to restore because self-stabilizing feedbacks of phytoplankton dominance can impede the establishment of BPP. BPP in lakes is light limited, and ecosystem models can provide guidance for determining the water clarity necessary to re-establish BPP dominance. We developed a multi-tiered framework for the restoration of shallow, eutrophic lakes that incorporates multiple turbidity sources, lake morphometry, and water-level fluctuations to determine water-clarity thresholds above which BPP dominance may be established. We present a case study applying this restoration target framework to a large, shallow lake (Utah Lake, Utah, USA), where water clarity was greatly impeded by sediment resuspension and high algal biomass. Our analysis, which used commonly available lake-monitoring data, indicated that a return to BPP dominance is possible in Utah Lake, particularly if external nutrient loading to its shallow, wind-protected bays is reduced. Our novel framework incorporates regime shift theory to improve shallow, eutrophic lake restoration efforts. By incorporating ecological feedbacks when identifying the restoration targets necessary for returning a lake to a self-stabilizing, clear-water regime, this restoration target framework offers economical and logistical advantages over strategies that focus solely on phytoplankton management or fish biomanipulation.
{"title":"Primary production modeling identifies restoration targets for shifting shallow, eutrophic lakes to clear-water regimes","authors":"L. King, J. Brahney, Scott Daly, M. Paul, Kateri R. Salk, S. Brothers","doi":"10.1086/723892","DOIUrl":"https://doi.org/10.1086/723892","url":null,"abstract":"Benthic primary production (BPP) plays an important functional role in lakes, improving water quality by stabilizing clear-water regimes. Shallow, eutrophic lakes lacking BPP communities can be difficult to restore because self-stabilizing feedbacks of phytoplankton dominance can impede the establishment of BPP. BPP in lakes is light limited, and ecosystem models can provide guidance for determining the water clarity necessary to re-establish BPP dominance. We developed a multi-tiered framework for the restoration of shallow, eutrophic lakes that incorporates multiple turbidity sources, lake morphometry, and water-level fluctuations to determine water-clarity thresholds above which BPP dominance may be established. We present a case study applying this restoration target framework to a large, shallow lake (Utah Lake, Utah, USA), where water clarity was greatly impeded by sediment resuspension and high algal biomass. Our analysis, which used commonly available lake-monitoring data, indicated that a return to BPP dominance is possible in Utah Lake, particularly if external nutrient loading to its shallow, wind-protected bays is reduced. Our novel framework incorporates regime shift theory to improve shallow, eutrophic lake restoration efforts. By incorporating ecological feedbacks when identifying the restoration targets necessary for returning a lake to a self-stabilizing, clear-water regime, this restoration target framework offers economical and logistical advantages over strategies that focus solely on phytoplankton management or fish biomanipulation.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"42 1","pages":"44 - 57"},"PeriodicalIF":1.8,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43937144","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}
Halle Nienhaus, S. Fitzpatrick, D. Bloom, Tiffany A. Schriever
Population genetic connectivity is influenced by multiple abiotic and biotic attributes, including geography, dispersal ability, and life history, which may lead to different patterns of population structure of organisms occupying similar habitats. We investigated how differences in dispersal ability and biogeographic gradients correspond with population structuring of 3 aquatic insect species found within naturally fragmented interdunal wetlands along the eastern shoreline of Lake Michigan in midwestern USA. Interdunal wetlands are small, highly fragmented, and patchily distributed along the eastern coast of Lake Michigan, USA. Our focal species, Anax junius (Drury, 1773), Notonecta undulata Say, 1832, and Caenis amica Hagen, 1861 were chosen as high, intermediate, and low dispersers, respectively. We hypothesized that all insect populations experience isolation by distance with relatively low gene flow among sites, but that the strength of isolation by distance varies with dispersal ability. We used cytochrome c oxidase subunit I sequence data to confirm species identification and restriction enzyme-association DNA sequencing for population genomic analyses. Our cytochrome c oxidase subunit I data revealed that Caenis populations consisted of multiple species split along a latitudinal gradient. Restriction site-association DNA sequencing data showed that A. junius displayed strong isolation by distance, where N. undulata did not. Additionally, both A. junius and N. undulata populations displayed 2 genetic clusters along the coastline, and genetic diversity increased along with latitude. These results indicate that biogeographical variables, such as latitude and covarying abiotic factors, may be stronger predictors of population structure than dispersal ability and that inference of population structure within aquatic macroinvertebrates should be on a species-specific basis.
{"title":"Dispersal ability and biogeographic gradients influence gene flow of 3 aquatic insects in Laurentian Great Lakes interdunal wetlands","authors":"Halle Nienhaus, S. Fitzpatrick, D. Bloom, Tiffany A. Schriever","doi":"10.1086/723893","DOIUrl":"https://doi.org/10.1086/723893","url":null,"abstract":"Population genetic connectivity is influenced by multiple abiotic and biotic attributes, including geography, dispersal ability, and life history, which may lead to different patterns of population structure of organisms occupying similar habitats. We investigated how differences in dispersal ability and biogeographic gradients correspond with population structuring of 3 aquatic insect species found within naturally fragmented interdunal wetlands along the eastern shoreline of Lake Michigan in midwestern USA. Interdunal wetlands are small, highly fragmented, and patchily distributed along the eastern coast of Lake Michigan, USA. Our focal species, Anax junius (Drury, 1773), Notonecta undulata Say, 1832, and Caenis amica Hagen, 1861 were chosen as high, intermediate, and low dispersers, respectively. We hypothesized that all insect populations experience isolation by distance with relatively low gene flow among sites, but that the strength of isolation by distance varies with dispersal ability. We used cytochrome c oxidase subunit I sequence data to confirm species identification and restriction enzyme-association DNA sequencing for population genomic analyses. Our cytochrome c oxidase subunit I data revealed that Caenis populations consisted of multiple species split along a latitudinal gradient. Restriction site-association DNA sequencing data showed that A. junius displayed strong isolation by distance, where N. undulata did not. Additionally, both A. junius and N. undulata populations displayed 2 genetic clusters along the coastline, and genetic diversity increased along with latitude. These results indicate that biogeographical variables, such as latitude and covarying abiotic factors, may be stronger predictors of population structure than dispersal ability and that inference of population structure within aquatic macroinvertebrates should be on a species-specific basis.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"42 1","pages":"88 - 103"},"PeriodicalIF":1.8,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41518417","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}
Pengfei Zhan, Hongwei Li, Wanzhe Cui, Yi Wang, Zhen-ya Liu, De-rong Xiao, Hang Wang
Phyllosphere microbes are essential in the mediation of plant–soil biogeochemical recycling during the decomposition of plant litter in wetland ecosystems. However, there are few studies into microbial community succession in phyllosphere microbial communities in wetlands, and their functional attributes across a full period of wetland plant litter decomposition remain unclear. Here, we collected leaf samples of Typha latifolia var. orientalis (C. Presl.) Rohrb., an emergent wetland plant, during various stages of decomposition (growing, standing, lodging, and submerging stages) to investigate fungal and bacterial assemblage succession in the phyllosphere. We then parsed these assemblages into specific fungal trophic modes and bacterial phenotypes. Over the litter decomposition period, both fungal and bacterial assemblages underwent distinct succession, with generally increasing alpha diversity, and the proportion of litter microbes originating from sediments increased with decomposition. Saprotrophic and pathotrophic fungi dominated the fungal assemblage in the early stages of decomposition, but their dominance was replaced by undefined fungi as decomposition progressed. Relative abundances of both pathotrophic fungi and potentially pathogenic bacteria increased from the growing to the standing stage, implying that there was a turning point in assemblage composition shortly after plant leaf death. Gram-positive and gram-negative bacteria had opposite trends in their relative abundances over successive decomposition stages. When plant litter entered the water, bacteria tolerant of oxidative stress gradually decreased in abundance, but anaerobic bacteria abundance increased. We also aimed to determine the relationships between predicted microbial functional traits and leaf litter physicochemical attributes. Lignin and N content were the predominant predictors of decomposer fungal trophic modes and bacterial phenotypes. These findings provide evidence that the complex litter decomposition seen in wetlands is accompanied by a dynamic cross-kingdom succession of phyllospheric microbial communities, coupled with distinct changes in the phenotypes of the microbes present. Insights into phyllospheric microbial functional traits have implications for better elucidating the plant litter cycle for wetland plants.
在湿地生态系统植物凋落物分解过程中，层球微生物在植物-土壤生物地球化学循环中起着重要的中介作用。然而，湿地层层微生物群落演替研究较少，其在湿地植物凋落物分解全周期内的功能属性尚不清楚。本研究采集了热带叶霉(Typha latifolia var. orientalis, C. Presl.)的叶片样品。Rohrb。在不同的分解阶段(生长、直立、倒伏和淹没阶段)，研究根层圈中真菌和细菌的组合演替。然后我们将这些组合解析为特定的真菌营养模式和细菌表型。在凋落物分解过程中，真菌和细菌组合具有明显的演替特征，α多样性总体呈增加趋势，来源于沉积物的凋落物微生物比例随着分解而增加。腐养真菌和致病性真菌在分解早期占主导地位，但随着分解的进行，它们的优势地位被未定义的真菌所取代。致病性真菌和潜在致病性细菌的相对丰度从生长阶段到站立阶段都有所增加，这表明植物叶片死亡后不久，组合组成出现了转折点。革兰氏阳性菌和革兰氏阴性菌的相对丰度在不同的分解阶段呈相反的趋势。当植物凋落物进入水体后，耐氧化细菌数量逐渐减少，而厌氧细菌数量增加。我们还旨在确定预测的微生物功能性状与凋落叶理化性状之间的关系。木质素和氮含量是分解者真菌营养模式和细菌表型的主要预测因子。这些发现提供了证据，表明湿地中看到的复杂凋落物分解伴随着层层微生物群落的动态跨界演替，以及存在的微生物表型的明显变化。对层层微生物功能特性的深入研究有助于更好地阐明湿地植物凋落物循环。
{"title":"Functional insights into succession in a phyllospheric microbial community across a full period of aquatic plant litter decomposition","authors":"Pengfei Zhan, Hongwei Li, Wanzhe Cui, Yi Wang, Zhen-ya Liu, De-rong Xiao, Hang Wang","doi":"10.1086/724015","DOIUrl":"https://doi.org/10.1086/724015","url":null,"abstract":"Phyllosphere microbes are essential in the mediation of plant–soil biogeochemical recycling during the decomposition of plant litter in wetland ecosystems. However, there are few studies into microbial community succession in phyllosphere microbial communities in wetlands, and their functional attributes across a full period of wetland plant litter decomposition remain unclear. Here, we collected leaf samples of Typha latifolia var. orientalis (C. Presl.) Rohrb., an emergent wetland plant, during various stages of decomposition (growing, standing, lodging, and submerging stages) to investigate fungal and bacterial assemblage succession in the phyllosphere. We then parsed these assemblages into specific fungal trophic modes and bacterial phenotypes. Over the litter decomposition period, both fungal and bacterial assemblages underwent distinct succession, with generally increasing alpha diversity, and the proportion of litter microbes originating from sediments increased with decomposition. Saprotrophic and pathotrophic fungi dominated the fungal assemblage in the early stages of decomposition, but their dominance was replaced by undefined fungi as decomposition progressed. Relative abundances of both pathotrophic fungi and potentially pathogenic bacteria increased from the growing to the standing stage, implying that there was a turning point in assemblage composition shortly after plant leaf death. Gram-positive and gram-negative bacteria had opposite trends in their relative abundances over successive decomposition stages. When plant litter entered the water, bacteria tolerant of oxidative stress gradually decreased in abundance, but anaerobic bacteria abundance increased. We also aimed to determine the relationships between predicted microbial functional traits and leaf litter physicochemical attributes. Lignin and N content were the predominant predictors of decomposer fungal trophic modes and bacterial phenotypes. These findings provide evidence that the complex litter decomposition seen in wetlands is accompanied by a dynamic cross-kingdom succession of phyllospheric microbial communities, coupled with distinct changes in the phenotypes of the microbes present. Insights into phyllospheric microbial functional traits have implications for better elucidating the plant litter cycle for wetland plants.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"42 1","pages":"13 - 32"},"PeriodicalIF":1.8,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41846982","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}
Abby Dalke, A. M. Erickson, Bailey R Tasker, Skylar Riley, P. Hurst, Sarah Cooney, Scott A Griffith, Betsy A Bancroft
Freshwater ecosystems are threatened by climate change and invasive species. Amphibians are important members of freshwater communities and are susceptible to negative effects of climate change and invasion. Furthermore, both climate change and invasion can influence density of amphibian larvae at the microhabitat scale because of larval clustering. To understand the effects of climate change and invasion on Pacific Chorus Frog Pseudacris regilla (Baird and Girard, 1852) larvae, a 2 × 2 × 2 factorial experiment was carried out with a climate treatment (future/historical; simulated as changes in both temperature and hydroperiod), indirect exposure to the invasive Brook Stickleback Culaea inconstans (Kirtland, 1840) fish (chemical cues present/absent), and conspecific density (conspecific present/absent). We measured tadpole survival and development rate along with variables related to body shape, including mass, growth, growth rate, body mass index, tail fin depth, tail muscle depth, tail muscle width, and rear limb length. We assessed the effects of 3 common and important stressors (climate, invasive species, and density) alone and in combination with the other stressors to explore their interactions. Climate change, as simulated by our study, had large effects on Pacific Chorus Frog tadpole development and body shape. Brook Stickleback chemical cues had smaller but important effects on body shape and development rate when combined with additional stressors. Competition because of presence of a conspecific tadpole also reduced survival and had large effects on body shape. Pairwise interactions were largely additive or antagonistic. Three-way stressor interactions were most often antagonistic, resulting in less-than-additive effects of the 3 stressors together. However, 3 synergistic 3-way emergent interactions were detected. When all 3 stressors were present, development rate was faster than expected but rear limb length and tail muscle width were smaller than expected. Our results illustrate that climate change and conspecific density have wide-ranging effects on amphibian growth, development, and morphology—effects which may carry over into the terrestrial stage and reduce fitness. Furthermore, our findings reveal complex stressor interactions that were not predictable from single stressor effects or pairwise stressor effects, illustrating the difficulty in predicting multiple stressor interactions in freshwater systems.
淡水生态系统受到气候变化和物种入侵的威胁。两栖动物是淡水群落的重要成员，容易受到气候变化和入侵的负面影响。此外，气候变化和外来入侵都可以影响微生境尺度上两栖动物幼虫的密度，因为幼虫聚集在一起。为了了解气候变化和入侵对太平洋合唱蛙(Baird and Girard, 1852)幼虫的影响，进行了2 × 2 × 2因子试验，并进行了气候处理(未来/历史;模拟温度和水周期的变化)，间接暴露于入侵的布鲁克棘鱼(Kirtland, 1840)鱼(化学线索存在/不存在)，以及同种密度(同种存在/不存在)。我们测量了蝌蚪的存活率和发育率，以及与体型相关的变量，包括质量、生长、生长速度、体重指数、尾鳍深度、尾肌深度、尾肌宽度和后肢长度。我们评估了3种常见和重要的压力源(气候、入侵物种和密度)单独和与其他压力源联合的影响，以探索它们之间的相互作用。我们的研究模拟了气候变化对太平洋合唱蛙蝌蚪发育和体型的影响。当与额外的压力源结合时，布鲁克棘鱼的化学线索对体型和发育速度的影响较小，但很重要。由于同一蝌蚪的存在而产生的竞争也降低了存活率，并对体型产生了很大影响。成对相互作用主要是相加性或拮抗性的。三种应激源的相互作用通常是对抗性的，导致三种应激源的加性效应小于加性效应。然而，检测到3种协同的3-way紧急相互作用。当3种应激源同时存在时，发育速度比预期快，但后肢长度和尾肌宽度比预期小。我们的研究结果表明，气候变化和同种密度对两栖动物的生长、发育和形态效应具有广泛的影响，这些影响可能会延续到陆地阶段并降低适应度。此外，我们的研究结果揭示了复杂的压力源相互作用，无法从单一压力源效应或成对压力源效应中预测，这说明了预测淡水系统中多个压力源相互作用的困难。
{"title":"Multiple interacting stressors influence development, growth, and morphology of Pacific Chorus Frog (Pseudacris regilla) larvae","authors":"Abby Dalke, A. M. Erickson, Bailey R Tasker, Skylar Riley, P. Hurst, Sarah Cooney, Scott A Griffith, Betsy A Bancroft","doi":"10.1086/723894","DOIUrl":"https://doi.org/10.1086/723894","url":null,"abstract":"Freshwater ecosystems are threatened by climate change and invasive species. Amphibians are important members of freshwater communities and are susceptible to negative effects of climate change and invasion. Furthermore, both climate change and invasion can influence density of amphibian larvae at the microhabitat scale because of larval clustering. To understand the effects of climate change and invasion on Pacific Chorus Frog Pseudacris regilla (Baird and Girard, 1852) larvae, a 2 × 2 × 2 factorial experiment was carried out with a climate treatment (future/historical; simulated as changes in both temperature and hydroperiod), indirect exposure to the invasive Brook Stickleback Culaea inconstans (Kirtland, 1840) fish (chemical cues present/absent), and conspecific density (conspecific present/absent). We measured tadpole survival and development rate along with variables related to body shape, including mass, growth, growth rate, body mass index, tail fin depth, tail muscle depth, tail muscle width, and rear limb length. We assessed the effects of 3 common and important stressors (climate, invasive species, and density) alone and in combination with the other stressors to explore their interactions. Climate change, as simulated by our study, had large effects on Pacific Chorus Frog tadpole development and body shape. Brook Stickleback chemical cues had smaller but important effects on body shape and development rate when combined with additional stressors. Competition because of presence of a conspecific tadpole also reduced survival and had large effects on body shape. Pairwise interactions were largely additive or antagonistic. Three-way stressor interactions were most often antagonistic, resulting in less-than-additive effects of the 3 stressors together. However, 3 synergistic 3-way emergent interactions were detected. When all 3 stressors were present, development rate was faster than expected but rear limb length and tail muscle width were smaller than expected. Our results illustrate that climate change and conspecific density have wide-ranging effects on amphibian growth, development, and morphology—effects which may carry over into the terrestrial stage and reduce fitness. Furthermore, our findings reveal complex stressor interactions that were not predictable from single stressor effects or pairwise stressor effects, illustrating the difficulty in predicting multiple stressor interactions in freshwater systems.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"42 1","pages":"118 - 132"},"PeriodicalIF":1.8,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47756912","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}
Oviposition is a critical step in the life cycles of aquatic insects. Adult caddisflies exhibit a variety of oviposition methods. In some species, females enter freshwaters to oviposit on submerged substrates. Here, we compile information on North American caddisflies that are known to dive and swim to oviposit and have sexually dimorphic leg characteristics that may be adaptations for swimming, diving, or both. We also report unexpected underwater captures of adult females of 3 caddisfly species in Willamette Basin reservoirs in Oregon, USA, including the deepest dive depths ever recorded for adult female caddisflies. From these captures, we note sexually dimorphic leg widening in the species Hydropsyche centra Ross, 1938 for the first time, confirm widened mesothoracic leg segments of Hydropsyche occidentalis Banks, 1900 adult females, and note fringes of long hairs on meso- and metathoracic tibiae and basal tarsal segments of Hydroptila argosa Ross, 1938 females. We also note fringes of long hairs on the meso- and metathoracic legs of Hydroptila ajax Ross, 1938 females from the banks of the Willamette River. The presumed oviposition attempts of caddisflies underwater in large, deep reservoirs suggest that these caddisflies may misinterpret oviposition cues in altered habitats and waste reproductive efforts. Greater understanding of caddisfly oviposition methods and abilities may be important for long-term conservation and restoration efforts supporting biodiversity in freshwater habitats.
产卵是水生昆虫生命周期中的一个关键步骤。成虫的产卵方式多种多样。在一些物种中，雌性进入淡水中，在淹没的基质上产卵。在这里，我们汇编了北美球童的信息，这些球童已知会潜水和游泳产卵，具有性二型腿特征，可能适应游泳、潜水或两者兼而有之。我们还报告了在美国俄勒冈州威拉米特盆地水库中意外捕获的3种成年雌性球童，包括有记录以来成年雌性球丁的最深潜水深度。从这些照片中，我们首次注意到Hydrophyl centra Ross（1938年）物种的性二型腿变宽，确认了Hydrophyle occidentalis Banks（1900名成年雌性）的中胸腿段变宽，并注意到了Hydrophila argosa Ross（38名雌性）中胸和后胸胫骨以及基底跗骨段上的长毛条纹。我们还注意到，来自威拉米特河畔的1938只雌性阿贾克斯-罗斯水怪的中胸和后胸腿上有长毛。据推测，在大型深层水库中，石蛾在水下产卵的尝试表明，这些石蛾可能会误解栖息地变化中的产卵线索，并浪费繁殖努力。更好地了解caddisfly的产卵方法和能力，对于支持淡水栖息地生物多样性的长期保护和恢复工作可能很重要。
{"title":"Caddisfly dives for oviposition: Record-shattering depths and poor life choices in a dammed river system","authors":"W. Gerth, C. Murphy, I. Arismendi","doi":"10.1086/724053","DOIUrl":"https://doi.org/10.1086/724053","url":null,"abstract":"Oviposition is a critical step in the life cycles of aquatic insects. Adult caddisflies exhibit a variety of oviposition methods. In some species, females enter freshwaters to oviposit on submerged substrates. Here, we compile information on North American caddisflies that are known to dive and swim to oviposit and have sexually dimorphic leg characteristics that may be adaptations for swimming, diving, or both. We also report unexpected underwater captures of adult females of 3 caddisfly species in Willamette Basin reservoirs in Oregon, USA, including the deepest dive depths ever recorded for adult female caddisflies. From these captures, we note sexually dimorphic leg widening in the species Hydropsyche centra Ross, 1938 for the first time, confirm widened mesothoracic leg segments of Hydropsyche occidentalis Banks, 1900 adult females, and note fringes of long hairs on meso- and metathoracic tibiae and basal tarsal segments of Hydroptila argosa Ross, 1938 females. We also note fringes of long hairs on the meso- and metathoracic legs of Hydroptila ajax Ross, 1938 females from the banks of the Willamette River. The presumed oviposition attempts of caddisflies underwater in large, deep reservoirs suggest that these caddisflies may misinterpret oviposition cues in altered habitats and waste reproductive efforts. Greater understanding of caddisfly oviposition methods and abilities may be important for long-term conservation and restoration efforts supporting biodiversity in freshwater habitats.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"42 1","pages":"104 - 117"},"PeriodicalIF":1.8,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43385902","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}
Land managers increasingly use wetland restoration to improve water quality, particularly in cultivated landscapes. In agricultural wetland restoration, managers regularly excavate accumulated sediments eroded from the surrounding landscape to increase water storage capacity, decrease invasive species cover, or improve water quality. However, it is unclear whether the effects of sediment excavation are influenced by wetland hydroperiod. Additionally, we lack data on how long excavation effects persist in restored wetlands. We examined dissolved nutrient concentrations (i.e., NH4+, NO3–, total dissolved N, soluble reactive P, total dissolved P, and dissolved organic C) as proxies for water quality in 54 restored agricultural wetlands ranging from 1 to 10 y post-restoration in the Prairie Pothole Region of west central Minnesota, USA. In 26 of these wetlands, restoration practitioners restored natural (i.e., either seasonal or semipermanent inundation) hydrological regimes by removing subsurface tile drainage and plugging surface drainage ditches (business-as-usual treatment). In 28 wetlands, practitioners removed accumulated sediment and redeposited it on the surrounding landscape (excavated treatment) prior to restoring hydrology. We found that wetlands in the excavated treatment group initially experienced reduced dissolved P concentrations, but over time P levels increased, particularly in wetlands with shorter hydroperiods. Excavated wetlands had lower NH4+ and dissolved organic C concentrations compared with business-as-usual wetlands, but the trend was driven by differences between restoration treatments in semipermanent wetlands. N and P dynamics were almost universally related to hydroperiod, both immediately following restoration and over the ensuing years. We postulate that the effects of hydroperiod are likely related to differences in redox conditions via direct mechanisms (water level fluctuations related to hydroperiod) and indirect mechanisms (development of dense emergent macrophyte communities in seasonal wetlands). In basins with seasonal hydroperiod, inorganic N concentrations decreased over time and inorganic P concentrations increased, suggesting net P mobilization concurrent with growing N limitation. Our results illustrate that hydroperiod regulates the expression of legacy P following wetland restoration, with little long-term effect of sediment removal on water quality outcomes.
{"title":"Water-quality outcomes of wetland restoration depend on hydroperiod rather than restoration strategy","authors":"Sarah G. Winikoff, J. Finlay","doi":"10.1086/724014","DOIUrl":"https://doi.org/10.1086/724014","url":null,"abstract":"Land managers increasingly use wetland restoration to improve water quality, particularly in cultivated landscapes. In agricultural wetland restoration, managers regularly excavate accumulated sediments eroded from the surrounding landscape to increase water storage capacity, decrease invasive species cover, or improve water quality. However, it is unclear whether the effects of sediment excavation are influenced by wetland hydroperiod. Additionally, we lack data on how long excavation effects persist in restored wetlands. We examined dissolved nutrient concentrations (i.e., NH4+, NO3–, total dissolved N, soluble reactive P, total dissolved P, and dissolved organic C) as proxies for water quality in 54 restored agricultural wetlands ranging from 1 to 10 y post-restoration in the Prairie Pothole Region of west central Minnesota, USA. In 26 of these wetlands, restoration practitioners restored natural (i.e., either seasonal or semipermanent inundation) hydrological regimes by removing subsurface tile drainage and plugging surface drainage ditches (business-as-usual treatment). In 28 wetlands, practitioners removed accumulated sediment and redeposited it on the surrounding landscape (excavated treatment) prior to restoring hydrology. We found that wetlands in the excavated treatment group initially experienced reduced dissolved P concentrations, but over time P levels increased, particularly in wetlands with shorter hydroperiods. Excavated wetlands had lower NH4+ and dissolved organic C concentrations compared with business-as-usual wetlands, but the trend was driven by differences between restoration treatments in semipermanent wetlands. N and P dynamics were almost universally related to hydroperiod, both immediately following restoration and over the ensuing years. We postulate that the effects of hydroperiod are likely related to differences in redox conditions via direct mechanisms (water level fluctuations related to hydroperiod) and indirect mechanisms (development of dense emergent macrophyte communities in seasonal wetlands). In basins with seasonal hydroperiod, inorganic N concentrations decreased over time and inorganic P concentrations increased, suggesting net P mobilization concurrent with growing N limitation. Our results illustrate that hydroperiod regulates the expression of legacy P following wetland restoration, with little long-term effect of sediment removal on water quality outcomes.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"42 1","pages":"70 - 87"},"PeriodicalIF":1.8,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45696016","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}
K. Gido, S. C. Hedden, Lindsey A. Bruckerhoff, C. Pennock, C. Hedden, Garrett W. Hopper, Elizabeth A. Renner, Eric R. Johnson, Ben J. Postlethwait
Poorly constructed road crossings block upstream movement of fish into stream reaches that provide critical habitat or connect isolated populations. Although removing these barriers is often a conservation priority, quantifying fish passage following removal has not been well studied, particularly in intermittent streams. In this study, we sought to understand how barriers influence the dispersal of fishes in intermittent prairie streams. We used passive integrated transponder tags and antenna stations to quantify fish movement of 3 prairie-stream fishes (Central Stoneroller Campostoma anomalum [Rafinesque, 1820], Southern Redbelly Dace Chrosomus erythrogaster [Rafinesque, 1820], and Creek Chub Semotilis atromaculatus [Mitchill, 1818]) through a road crossing in an intermittent prairie stream for 3 y before and 3 y after removing a perched culvert. We verified that no upstream fish movement occurred through the culvert, despite large aggregations of tagged fish in the intermittent reach below the culvert. In contrast, tagged individuals of all 3 species were detected above the road crossing in each of the 3 y following removal. We also tracked the recovery of these species, plus the Orangethroat Darter Etheostoma spectabile (Agassiz, 1854), following a severe drought in 2018 in 2 spring-fed tributary reaches, 1 without a downstream barrier and 1 with the removed downstream culvert. Surveys of the tributary reaches showed rapid recovery of fish densities following drought in the tributary without a downstream barrier. However, recovery at the site above the removed culvert appeared to be limited by a natural waterfall. Our observations suggest barrier removal allowed access to spawning habitat within the intermittent reach immediately upstream of the site, but other obstacles or shear distance to perennial spring-fed tributary reaches also limited recolonization following severe drought. Increased connectivity between perennial and intermittent reaches in prairie streams likely benefits fishes by increasing their resilience following disturbance and providing habitat during critical life stages.
{"title":"A perched culvert and natural obstructions limit fish dispersal in an intermittent prairie stream","authors":"K. Gido, S. C. Hedden, Lindsey A. Bruckerhoff, C. Pennock, C. Hedden, Garrett W. Hopper, Elizabeth A. Renner, Eric R. Johnson, Ben J. Postlethwait","doi":"10.1086/723046","DOIUrl":"https://doi.org/10.1086/723046","url":null,"abstract":"Poorly constructed road crossings block upstream movement of fish into stream reaches that provide critical habitat or connect isolated populations. Although removing these barriers is often a conservation priority, quantifying fish passage following removal has not been well studied, particularly in intermittent streams. In this study, we sought to understand how barriers influence the dispersal of fishes in intermittent prairie streams. We used passive integrated transponder tags and antenna stations to quantify fish movement of 3 prairie-stream fishes (Central Stoneroller Campostoma anomalum [Rafinesque, 1820], Southern Redbelly Dace Chrosomus erythrogaster [Rafinesque, 1820], and Creek Chub Semotilis atromaculatus [Mitchill, 1818]) through a road crossing in an intermittent prairie stream for 3 y before and 3 y after removing a perched culvert. We verified that no upstream fish movement occurred through the culvert, despite large aggregations of tagged fish in the intermittent reach below the culvert. In contrast, tagged individuals of all 3 species were detected above the road crossing in each of the 3 y following removal. We also tracked the recovery of these species, plus the Orangethroat Darter Etheostoma spectabile (Agassiz, 1854), following a severe drought in 2018 in 2 spring-fed tributary reaches, 1 without a downstream barrier and 1 with the removed downstream culvert. Surveys of the tributary reaches showed rapid recovery of fish densities following drought in the tributary without a downstream barrier. However, recovery at the site above the removed culvert appeared to be limited by a natural waterfall. Our observations suggest barrier removal allowed access to spawning habitat within the intermittent reach immediately upstream of the site, but other obstacles or shear distance to perennial spring-fed tributary reaches also limited recolonization following severe drought. Increased connectivity between perennial and intermittent reaches in prairie streams likely benefits fishes by increasing their resilience following disturbance and providing habitat during critical life stages.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"42 1","pages":"33 - 43"},"PeriodicalIF":1.8,"publicationDate":"2022-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46162678","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}
Konstanze Steiner, T. Drinan, A. Zaiko, Tracey Burton, S. Clearwater, Michael Stocker, Michael McMillan, T. Bayer, M. Vandergoes, S. Wood
The abundance of freshwater mussels is declining globally. To better understand and possibly reverse this trend, we need more information on the occurrence and distribution of freshwater mussels. Using environmental DNA (eDNA) to detect species is a sensitive and cost-effective approach that can complement conventional monitoring methods. The quantity and distribution of eDNA in a waterbody determines how many samples researchers need to collect for a successful survey. There has been limited research on appropriate sampling strategies for detecting freshwater mussel eDNA in lakes. The aim of this study was to compare the occurrence and concentration eDNA from the New Zealand freshwater mussel or kākahi (Echyridella menziesii Gray, 1843) with density data obtained from divers and to use statistical approach to determine the optimal number of samples required when establishing a monitoring program. We took surface-water samples for eDNA detection from 5 lakes of different size and depth. At the same locations, divers measured kākahi density using traditional transects. For eDNA, we amplified the mitochondrial cytochrome oxidase 1 gene using droplet digital polymerase chain reaction. All 5 lakes had substantial populations of kākahi and high eDNA occupancy (79%). We detected kākahi eDNA at both shallow and deep sites. Detectability (presence/absence) of kākahi eDNA varied between 61 and 96% and was generally higher in shallow small lakes which is likely related to the lake’s geomorphology. Our models indicated that sampling 4 sites in triplicate is sufficient to detect kākahi eDNA if occupancy is high (>80%), but the number of sites sampled needs to be increased in lakes where there is no prior knowledge on kākahi populations. The results of this study provide guidance that can be used to inform development of sampling strategies for kākahi monitoring in lakes.
{"title":"Heterogenous distribution of kākahi (freshwater mussel Echyridella menziesii) environmental DNA in 5 New Zealand lakes of differing size and geomorphology","authors":"Konstanze Steiner, T. Drinan, A. Zaiko, Tracey Burton, S. Clearwater, Michael Stocker, Michael McMillan, T. Bayer, M. Vandergoes, S. Wood","doi":"10.1086/722968","DOIUrl":"https://doi.org/10.1086/722968","url":null,"abstract":"The abundance of freshwater mussels is declining globally. To better understand and possibly reverse this trend, we need more information on the occurrence and distribution of freshwater mussels. Using environmental DNA (eDNA) to detect species is a sensitive and cost-effective approach that can complement conventional monitoring methods. The quantity and distribution of eDNA in a waterbody determines how many samples researchers need to collect for a successful survey. There has been limited research on appropriate sampling strategies for detecting freshwater mussel eDNA in lakes. The aim of this study was to compare the occurrence and concentration eDNA from the New Zealand freshwater mussel or kākahi (Echyridella menziesii Gray, 1843) with density data obtained from divers and to use statistical approach to determine the optimal number of samples required when establishing a monitoring program. We took surface-water samples for eDNA detection from 5 lakes of different size and depth. At the same locations, divers measured kākahi density using traditional transects. For eDNA, we amplified the mitochondrial cytochrome oxidase 1 gene using droplet digital polymerase chain reaction. All 5 lakes had substantial populations of kākahi and high eDNA occupancy (79%). We detected kākahi eDNA at both shallow and deep sites. Detectability (presence/absence) of kākahi eDNA varied between 61 and 96% and was generally higher in shallow small lakes which is likely related to the lake’s geomorphology. Our models indicated that sampling 4 sites in triplicate is sufficient to detect kākahi eDNA if occupancy is high (>80%), but the number of sites sampled needs to be increased in lakes where there is no prior knowledge on kākahi populations. The results of this study provide guidance that can be used to inform development of sampling strategies for kākahi monitoring in lakes.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"42 1","pages":"1 - 12"},"PeriodicalIF":1.8,"publicationDate":"2022-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49189072","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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