Freshwater Science最新文献

{"title":"Optimizing stormwater management to facilitate urban stream restoration via a science-based approach","authors":"M. Wooten, R. Hawley, C. Rust","doi":"10.1086/721031","DOIUrl":"https://doi.org/10.1086/721031","url":null,"abstract":"Stormwater management affecting an urban stream is most effective when managers design programs tailored to the physical characteristics of the stream and the political and socioeconomic characteristics of the community it serves. Likewise, restoration projects and policy implementation should be designed to address the needs of the local community. This paper documents the development and implementation of a science-based, community-driven approach to stormwater management by a United States regional stormwater utility, Sanitation District No. 1 (SD1) of Northern Kentucky, USA, that manages stormwater in 3 suburban counties in the greater metropolitan area of Cincinnati, Ohio, USA. SD1 began by establishing a hydrogeomorphic and biological monitoring program from 2006 to 2008 to gather the data needed to design a locally calibrated stormwater management program. SD1’s monitoring network has facilitated multiple cross-jurisdictional partnerships and provides validation for stormwater management rules and regulations that are tailored to Northern Kentucky. Moreover, the monitoring data has informed the activities of a watershed restoration program that prioritizes cost-effective geomorphic recovery by retrofitting existing stormwater management facilities. Furthermore, diverse stakeholders, such as local land developers, engineers, and members of the regulatory community, have embraced the data-driven approach and are currently collaborating with SD1 to incorporate hydrologic restoration via stormwater management activities into an existing program that generates stream mitigation credits. The sale of these credits, designed to mitigate the loss of stream habitat due to development, could then further fund the expansion of these restoration efforts. SD1’s approach could serve as a road map for other regional utilities hoping to tailor stormwater management to their streams and communities and find innovative funding sources for urban stream restoration.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"477 - 488"},"PeriodicalIF":1.8,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42936304","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}

{"title":"Influences of stream ecosystem respiration on stream network denitrification: Results from a simulation modeling experiment","authors":"S. Carlson, G. Poole","doi":"10.1086/720720","DOIUrl":"https://doi.org/10.1086/720720","url":null,"abstract":"Denitrification can remove substantial amounts of NO3− from stream networks, but controls on the magnitude and distribution of network-scale denitrification remain poorly understood. Prior research using an empirical relationship between stream [NO3−] and denitrification efficiency to construct a stream network denitrification model suggested that smaller, lower order streams contributed disproportionately to whole-network NO3− removal when NO3− loads were low. We expanded this model by incorporating an empirical relationship between whole-stream aerobic respiration rate and denitrification efficiency, which decreased the simulated sensitivity of NO3− removal to [NO3−] and displayed additional heterogeneity in NO3− removal associated with variation in respiration rates. We explored the sensitivity of the expanded model across a set of scenarios representing variation in stream respiration and NO3−-loading rates. Stream respiration rates used in these scenarios were determined from a theoretical relationship between aerobic respiration rate and stream temperature and were calculated for model scenarios representing warm (high respiration rate) and cool (low respiration rate) conditions. Our results indicated that reach- and network-scale denitrification is apt to be strongly influenced by respiration rates when NO3− supplies are high relative to removal rates. Therefore, the distribution of respiration rates across stream networks likely plays a more important role in determining spatial patterns of denitrification rates than previously described, highlighting a mechanism by which larger (higher order) streams may contribute substantially to whole-network denitrification.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"363 - 375"},"PeriodicalIF":1.8,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47100421","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}

{"title":"Responses of survival, growth, and feeding of the invasive Golden Apple Snail (Pomacea canaliculata) to salinity stress","authors":"Pengyuan Liu, B. Zhao, Jiaen Zhang, Z. Qin, Chunxia Zhang, Qinglin Jing, Jing Guo","doi":"10.1086/721026","DOIUrl":"https://doi.org/10.1086/721026","url":null,"abstract":"The Golden Apple Snail Pomacea canaliculata (Lamark, 1822) is one of the most aggressive invasive freshwater snails and has been found in tropical and subtropical regions around the world. Their presence threatens trophic structure in invaded ecosystems (e.g., wetlands) and harms human health both directly (e.g., as a vector of parasites) and indirectly (e.g., through altering the provision of ecosystem services from uninvaded ecosystems). The tolerance of Golden Apple Snails to saltwater is of concern because they may pose an invasion risk into estuary habitats. We studied the salinity tolerance of Golden Apple Snails by determining differences in their survival, growth, and feeding at 5 salinity levels (0, 2.5, 5.0, 7.5, and 10.0 practical salinity units [PSU]) over 30 d. Artificial seawater was prepared with aerated tap water and synthetic sea salt, consisting of NaCl (68.88%), KCl (1.79%), CaCl2 (2.55%), MgCl2 (8.67%), MgSO4 (5.36%), and NaHCO3 (12.75%). Snails were classified into 3 life stages based on shell length: juvenile (10–19.99 mm), mature (20–29.99 mm), and old snails (30–39.99 mm). Snails at all 3 life stages survived in salinities of 0 to 5.0 PSU but died within 9 d in salinities of 7.5 and 10.0 PSU. The survival percentage of snails decreased in the order: mature > old > juvenile. Snails across all life stages had reduced shell and mass growth with salinity exposure, but their feeding rate in salinity 2.5 and 5.0 PSU became similar to the control group after 23 d. Generally, Golden Apple Snails may live in waters of ≤5.0 PSU. Therefore, special attention should be paid to the activity of Golden Apple Snails in tropical and subtropical areas with salinities ≤5.0 PSU, which would be important for protecting against the snails’ destructive effects on productive resources.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"376 - 385"},"PeriodicalIF":1.8,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45393130","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}

{"title":"Qc threshold departs from theoretical Qc in urban watersheds: The role of streambed mobility data in managing the urban disturbance regime","authors":"R. Hawley, Kathryn L. Russell, L. Olinde","doi":"10.1086/720939","DOIUrl":"https://doi.org/10.1086/720939","url":null,"abstract":"The threshold discharge (Qc) for streambed mobilization is both biologically and geomorphically relevant to stream ecosystems. Excess streambed mobilization can disturb benthic organisms and initiate cycles of channel instability. The mechanistic relevance of Qc gives it great utility for aquatic ecosystem studies, stormwater management, and stream restoration design. However, field and laboratory data document considerable variability in Qc across hydrogeomorphic settings, underscoring the importance of using field data to calibrate the Qc estimate for a given stream or region. This paper shows how both high- and low-tech monitoring protocols can be used to constrain a Qc estimate, depending on monitoring program goals and budgets. Data from 3 hydrogeomorphically distinct settings in the USA and Australia show that the departure of Qc from theoretical estimates increases with watershed imperviousness. Although Qc estimates derived from conventional critical Shields stress values tend to be a reasonable and conservative starting point for stormwater management in streams that lack site-specific or regional data, streambed mobility monitoring is recommended to calibrate and validate Qc estimates for a stream or region prior to making large investments in stormwater interventions aimed at mitigating the urban streambed disturbance regime.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"489 - 506"},"PeriodicalIF":1.8,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45550388","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}

{"title":"Have stream diatom assemblages changed a decade after the loss of a foundation riparian tree species in a headwater Appalachian watershed?","authors":"Kelsey J. Solomon, R. Bixby, S. Wenger, C. Pringle","doi":"10.1086/720136","DOIUrl":"https://doi.org/10.1086/720136","url":null,"abstract":"Terrestrial and stream ecosystems are interconnected, with changes in one system cascading to affect the other. Tree mortality related to nonnative pest infestation has increased, yet we do not understand the effects that riparian tree species losses will have on the structural characteristics of stream ecosystems. We compared riparian canopy cover, algal standing crop, and diatom assemblage composition in 8 southern Appalachian headwater stream reaches within the Coweeta Hydrologic Laboratory in North Carolina, USA, before and after a massive die-off of riparian eastern hemlock (Tsuga canadensis [L.] Carr.) related to the introduction of hemlock woolly adelgid (Adelges tsugae Annand), an invasive insect. We analyzed historical preserved algal samples collected prior to hemlock die-off, in both summer (September 2005) and winter (January 2006), and used multivariate analyses to compare them to samples collected in the same 8 reaches and seasons 13 y following hemlock die-off (2018–2019). We predicted that increased canopy openness following hemlock death would change light availability and lead to higher standing crop and increases in the relative biovolume of high-profile diatoms. Contrary to our expectations, we found little difference in canopy cover and lower algal standing crop 13 y post-hemlock die-off, likely due to increased basal area of the understory shrub, Rhododendron maximum L., that replaced shade cover formerly provided by hemlock. Diatom assemblages were dominated by acidophilic taxa (e.g., Eunotia spp.) across all stream reaches before and after hemlock die-off. We observed some shifts in diatom assemblage composition, but the relative biovolume of a majority of the top 20 most abundant taxa, including Eunotia incisa W. Sm. ex W. Greg., Nupela lapidosa (Krasske) Lange-Bert., and Meridion alansmithii Brant (an endemic taxon), remained relatively unchanged 13 y after hemlock mortality. Diatom assemblages differed post-hemlock die-off in summer but not winter due to a decrease in the relative biovolume of Eunotia metamondon complex and an increase in the relative biovolume of Eunotia rhomboidea complex. Our study highlights the relative stability of diatom assemblage composition in southern Appalachian streams and the importance of long-term studies following a major riparian disturbance.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"342 - 361"},"PeriodicalIF":1.8,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41713727","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}

{"title":"Freshwater floodplain habitats buffer native food webs from negative effects of nonnative centrarchids and bullfrogs","authors":"M. A. Holgerson, Martha Barnard, Byung-Gu Ahn, M. Hayes, A. Strecker","doi":"10.1086/720137","DOIUrl":"https://doi.org/10.1086/720137","url":null,"abstract":"Species introductions are common in freshwater environments and have the potential to transform community and ecosystem structure. Predatory centrarchid fishes and American Bullfrogs (Lithobates catesbeianus Shaw, 1802 previously Rana catesbeiana) are both widespread aquatic invaders implicated in native amphibian declines. In lowland ecosystems, co-occurrence between native and nonnative amphibian and fish taxa is common; however, the mechanisms that facilitate their co-occurrence are poorly studied. Stable isotope analysis offers a tool to examine trophic interactions among native and nonnative taxa, including predation, competition, and shifting food resource availability, which may provide mechanistic insight into the drivers of co-occurrence. In this study, we used stable isotopes (δ13C and δ15N) to determine how the trophic structure of native fishes and amphibians differs between waterbodies with and without nonnative centrarchid fishes and bullfrogs across a floodplain in southwestern Washington, USA. We hypothesized that native species alter their feeding strategies to reduce niche overlap with nonnative taxa. In the presence of nonnative taxa, Three-spine Stickleback (Gasterosteus aculeatus Linnaeus, 1758), all native larval salamander species (Ambystoma gracile Baird, 1859 and Ambystoma macrodactylum Baird, 1850), and 1 of 2 native larval frog species (Rana aurora Baird and Girard, 1852) exhibited shifts in food resources or trophic position. Despite trophic differences, only 1 species (A. macrodactylum) had a smaller niche size in the presence of nonnatives. The observed trophic shifts reflect changes in habitat or food resources, which may reduce competition or predation and promote co-occurrence between nonnative and native taxa. Our results suggest that the co-occurrence of native and nonnative amphibians and fishes in lowland floodplain habitats may be facilitated by a broad range of food resources and complex habitat structure.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"327 - 341"},"PeriodicalIF":1.8,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47269805","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}

{"title":"Assessing seasonal and biological indices of juvenile Chinook Salmon for freshwater decision triggers that increase ocean survival","authors":"Jennifer L. Gosselin, James J. Anderson, B. Sanderson, Mollie A. Middleton, B. Sandford, L. Weitkamp","doi":"10.1086/720007","DOIUrl":"https://doi.org/10.1086/720007","url":null,"abstract":"Decision triggers, used in adaptive management frameworks to decide when a specific management action will be implemented, are often informed by monitoring data. The identification and application of decision triggers is highly relevant to endangered fishes migrating through regulated rivers, as examined in the current study. The main goal was to determine whether seasonal patterns of behavioral, physical, and physiological indices of juveniles were related to subsequent smolt-to-adult return (SAR) survival and, if so, to determine whether these indices could be used to guide decisions related to the mitigation strategy of the juvenile fish transportation program in the Federal Columbia River Power System (Pacific Northwest, USA). Hatchery yearling Chinook Salmon (Oncorhynchus tshawytscha Walbaum in Artedi, 1792) were collected over the migration season at 3 dams in the hydrosystem and measured for fork length, wet mass, Fulton’s K (or condition factor), Na+/K+-ATPase (NKA) activity (or smoltification index), and % dry mass (or index of energetic reserves and smoltification). We estimated SAR survival from passive integrated transponder-tagged fish representative of our field samples and assessed its relationship to our fish indices, as well as indices of transported vs run-of-river passage and distance of sampling site to ocean. SAR survival was associated to interaction effects between juvenile fish transportation and % dry mass or NKA activity. Transported hatchery Chinook Salmon with dry mass <23% of whole fish wet mass and NKA activity >7 µmol ADP mg protein−1 h−1 showed greater SAR survival than their run-of-river counterparts. Fish with the highest predicted SAR survival had been transported and had fish indices consistent with smolts that were more developed (i.e., lower % dry mass and higher NKA activity). Furthermore, our results on % dry mass provided support for the hypothesis that greater lipid content increases fish buoyancy leading to greater susceptibility to predation. The buoyancy effect is expected to be greatest in hatchery fish. Overall, this study shows that decision triggers based on biological indices of migrating fish are potentially useful tools for in-season management.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"253 - 269"},"PeriodicalIF":1.8,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44781024","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}

{"title":"Nutrient availability modulates the effect of water abstraction on the metabolism of 2 lowland forested streams","authors":"I. Pardo, Lenka Kuglerová, L. García, E. Martí","doi":"10.1086/719990","DOIUrl":"https://doi.org/10.1086/719990","url":null,"abstract":"Climate change predictions for Southern Europe indicate an increase in the frequency and duration of summer low flows and water scarcity in streams. Droughts can cause substantial changes in aquatic communities and biogeochemical processes because they modify stream environmental conditions. Among the many physical, chemical, and biological variables that influence stream metabolism, nutrients may affect algae and heterotrophic microorganisms, and nutrient concentrations may vary with reduction in water discharge. We experimentally manipulated stream discharge and used a before–after control–impact paired design to assess how reduction of stream discharge affected metabolism (i.e., ecosystem respiration [ER] and gross primary production [GPP]). The study was done in 2 lowland forested streams in northwestern Spain with contrasting nutrient concentrations (i.e., mesotrophic: Caselas stream; eutrophic: Pego stream). In the 2 streams, metabolism was estimated before and after discharge manipulation. Prior to discharge reduction, the 2 streams were heterotrophic (i.e., GPP∶ER < 1), and GPP and ER were related in the eutrophic Pego. Discharge reduction increased GPP at the impacted reaches of the mesotrophic Caselas and decoupled GPP and ER at the Pego. An information-theoretic approach was used to assess which combinations of physical, chemical, and biological variables were most important to explain the variation in ER and GPP under the different hydrologic conditions. The observed differences between the 2 streams suggest that the metabolic response to stream drought can be modulated by the interplay between nutrient availability and the density of consumers feeding on resources, among other environmental variables. We show that longer summer periods and reduced stream discharge have the potential to increase daily hypoxia in nutrient-rich lowland stream ecosystems. Increased hypoxia can threaten biodiversity of stream ecosystems and reduce consumer pressure on basal instream resources, such as algae, bacteria, and fungi, which may, in turn, favor instream GPP. In addition, drying conditions seemed to favor autotrophic over heterotrophic activity under moderate nutrient availability (i.e., increase in the GPP∶ER ratio in the impacted Caselas reaches). Therefore, drought conditions not only affect overall daily rates of metabolic activity, but also the relative importance of different energy sources and organic matter for instream function. Our results show that discharge reduction caused by increased water scarcity, due to both climate change and water demand by human activities, can influence energy flow and organic matter dynamics through effects on the metabolism of forested lowland streams.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"299 - 314"},"PeriodicalIF":1.8,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47314470","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}

{"title":"Nutrient processing domains: Spatial and temporal patterns of material retention in running waters","authors":"H. Valett, M. Peipoch, G. Poole","doi":"10.1086/719991","DOIUrl":"https://doi.org/10.1086/719991","url":null,"abstract":"Reaches are a fundamental unit for lotic biogeochemical characterization, yet a functional classification of nutrient processing at the reach scale is currently lacking. Here, we introduce nutrient processing domains (NPDs) to integrate routing (nutrient delivery) and local (benthic uptake and transformation) processes that dictate longitudinal patterns of lotic biogeochemical function. An NPD is defined as a realm in functional space occupied by reaches that share similar biogeochemical character. Occupation of a given NPD reflects characteristic net material balance (NMB), exchange potential, and availability, associated with changes in solute load, the extent of hydrologic gain or loss, and changes in concentration from the head to the base of a reach, respectively. Using a mass-balance approach, we represent NMB as the effective solute flux (Feff, M L−2 T−1, where M = mass, L = length, and T = time), designating reaches as sources (+Feff) or sinks (−Feff). Discharge change along a reach is measured as the change in hydraulic load (ΔHL, L/T), reflecting the potential for import and export to influence solute loads. Finally, the ratio of downstream-to-upstream concentration (Cdwn:up) represents the net effect that processes have on nutrient availability. Using a 20-y historical record for N and P in the Upper Clark Fork River, Montana, USA, we employed this approach to 3 consecutive reaches covering nearly 90 km of channel length to address spatial and temporal dynamics in NPD behavior in a nutrient-rich, productive river system. For total N and total P, reaches typically occupied compiler or enhancer NPDs, displaying load increases without or with concomitant increases in concentration, respectively. In contrast, reaches were NO3− consumers, acting as sinks for NO3-N during summer and autumn. NO3− load reductions were typically accompanied by striking declines in concentration, despite positive exchange potential (i.e., +ΔHL). Measured Feff magnitudes for NO3− (−1.2 to −60.0 mg N m−2 d−1) were similar to those reported in the literature associated with autotrophic N demand. Individual reaches occupied contrasting NPDs for NO3-N and soluble reactive P by simultaneously serving as a sink for one and a source for the other. Hence, alternating reaches acted as enhancers or consumers, sequentially along the river, reflecting geologic and biological influences with implications for whole river behavior. The NPD approach combines routing influences of material exchange and local biological stream processes to provide a biogeochemical taxonomy for stream reaches with application to theory and practice.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"195 - 214"},"PeriodicalIF":1.8,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44809253","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}

{"title":"Molecular insight reveals broad-scale spatial patterns in floodplain ciliate assemblages, whereas morphology reflects local environmental controls","authors":"F. Lansac‐Tôha, P. R. B. Buosi, M. T. Baumgartner, M. Progênio, B. R. Meira, A. Cabral, B. T. Segovia, M. Dunthorn, Guillaume Lentendu, F. Lansac-Tôha, L. Velho","doi":"10.1086/719992","DOIUrl":"https://doi.org/10.1086/719992","url":null,"abstract":"One of the major goals in microbial ecology is to understand whether the empirical biogeographic patterns of macroorganisms also apply to microorganisms. Here, we used morphological data from live organisms, along with molecular data, to investigate the importance of spatial factors and environmental variables in influencing ciliate composition from floodplain lakes. Our main goal was to use 2 different approaches (morphological and molecular) to compare ciliate diversity and distribution patterns as well as to compare how these methods differ in their ability to detect distribution patterns and the roles of spatial and environmental factors that shape ciliate assemblages in the 4 largest floodplains in Brazil. Planktonic water samples were gathered from 33 lakes associated with 4 different river floodplain systems in Brazil. We analyzed ciliates in vivo and sequenced surface water DNA using a metabarcoding approach with general eukaryotic primers. We showed that the diversity of operational taxonomic units was much higher than that of morphospecies. Regardless of the method of identification, we found a consistent spatial assembly pattern of ciliate assemblages across the 4 floodplain systems. We also found that environmental filters had a stronger association with the morphological than with the molecular site-by-site dissimilarities. Meanwhile, biogeographic factors and the distance among sites limited the distribution of molecular-based composition, resulting in strong differences among the floodplain lakes analyzed. This finding suggests that ecological research and biomonitoring activities should find an equilibrium between morphological and molecular approaches because each approach provides unique insights.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"270 - 283"},"PeriodicalIF":1.8,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44856286","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}