The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform

Carla Ferragut - One of the best experts on this subject based on the ideXlab platform.

  • Environmental predictors of Algal Community structure of plankton, epipelon and epiphyton in a shallow tropical reservoir
    Brazilian Journal of Botany, 2019
    Co-Authors: Thiago Rodrigues Dos Santos, Carla Ferragut
    Abstract:

    Structural characteristics of Algal communities can be used to access environmental conditions, but there is a great need to identify the drivers of change in all habitats. This study evaluated the spatial and temporal changes in the phytoplankton, epipelon and epiphyton structures in a shallow reservoir. We investigated the determining factors of the structural variability and spatial differences in the species composition and Algal density in the three habitats. Bimonthly samplings were carried out for determination of the limnological variables and Algal communities. The rainy season was characterized by high nutrient availability and macrophyte coverage, and the communities were dominated by flagellate algae, as Chromulina elegans Doflein. The highest modification rate was found in the phytoplankton structure, followed by epiphyton and epipelon. Despite the species co-occurrence among phytoplankton, epipelon and epiphyton, the descriptor species presented different representativeness in communities. Planktonic and epiphytic algae were more associated with temporal variation in nutrient availability, while depth was more important for epipelic algae structuring. We conclude that the Algal Community in the plankton, epipelon and epiphyton was structured by different environmental factors, but descriptor species co-occurrence suggested an interrelationship between communities in this shallow reservoir with high abundance of macrophytes.

  • Influence of seasonality and rooted aquatic macrophyte on periphytic Algal Community on artificial substratum in a shallow tropical reservoir
    International Review of Hydrobiology, 2015
    Co-Authors: Mayara Ribeiro Casartelli, Carla Ferragut
    Abstract:

    The interrelationships of periphyton with macrophytes and phytoplankton are quite complex and poorly investigated in tropical reservoirs. We investigated the changes in the periphytic Algal Community structure at equidistant sites with and without macrophyte growth in four seasons in a shallow tropical reservoir. Our main objective was to evaluate the influence of the presence and absence of macrophytes, as well as seasonality, on changes in the periphytic Algal Community. Glass slides were submerged for 30 days for periphyton colonization. Environmental data on physical and chemical variables, periphyton, phytoplankton chlorophyll a, and macrophyte coverage were recorded for each site. Periphyton structure was analyzed for chlorophyll a, AFDM, Algal density, biovolume, species richness, and N:P molar ratio. Principal component analysis mainly ordinated sites along a gradient of temperature and nutrient concentration. Cluster analysis showed that the lowest similarity of periphytic Algal species composition was between seasons. The highest periphyton biomass and Algal abundance occurred in the dry season when there was reduced macrophyte coverage and phytoplankton chlorophyll a. Periphytic Algal descriptor species and total density were more sensitive to the presence/absence of macrophytes than were other structural attributes. We found that the periphytic Algal Community structure on artificial substratum was influenced by seasonality and presence of macrophyte (Nymphaea spp.), as well as by the interaction of these factors. Our results highlight the importance of macrophyte coverage and phytoplankton chlorophyll a to the periphytic Algal Community structure in the littoral zone. The relationship between primary producers needs further investigation in shallow tropical reservoirs.

  • periphytic Algal Community structure in relation to seasonal variation and macrophyte richness in a shallow tropical reservoir
    Hydrobiologia, 2015
    Co-Authors: Mariane Lima De Souza, Barbara Golebski Pellegrini, Carla Ferragut
    Abstract:

    The macrophyte structure can influence the development of periphytic Algal Community in a shallow ecosystem. We investigated the interrelationship between periphytic Algal Community on artificial substrate and macrophyte species richness during four seasons in a tropical shallow reservoir. The periphyton was evaluated by biomass (as AFDM), Algal abundance, species composition, and species richness. Limnological variables and macrophyte coverage were determined at sites with different macrophytes richness in littoral zone. Glass slides were used as the substrate and colonization time was 30 days. Periphytic Algal structure was significantly influenced by seasonality and macrophyte richness, as well as the interaction of two factors. Periphytic Algal density on natural and artificial substrates was negatively correlated with macrophyte richness and coverage. High biomass, Algal biovolume and dominance of Zygnemaphyceae occurred when there was an increase of Utricularia foliosa coverage (summer). Our results showed that the seasonality, and to a lesser extent macrophyte species richness, explained significant portion of the variability of periphyton biomass, Algal abundance, and taxonomic composition on artificial substrate. The changes in macrophyte Community may have direct consequences on the periphyton structure in a shallow tropical reservoir.

  • The successional phases of a periphytic Algal Community in a shallow tropical reservoir during the dry and rainy seasons
    Limnetica, 2013
    Co-Authors: Thiago Rodrigues Dos Santos, Carla Ferragut
    Abstract:

    The successional phases of a periphytic Algal Community in a tropical shallow reservoir during the dry and rainy seasons This study aims to describe the structural changes in a successional periphyton Community during the dry and rainy seasons in a shallow tropical reservoir. The sources of structural variability of the periphytic Algal Community were identified on successional and seasonal scales. Glass slides were placed in macrophyte stands for periphyton colonisation over 30 d. Samples were taken at intervals of hours (24 h, 27 h, 30 h, 33 h, 45 h, 48 h, 51 h, 54 h, and 57 h) and days (3 d, 6 d, 9 d, 12 d, 15 d, 20 d, 25 d, and 30 d). The limnological conditions differed significantly between the dry and rainy seasons. The biomass increment, total density, and total biovolume increased as the colonisation time increased in both climatic periods. A CCA showed the influence of seasonal and successional scales on periphytic Algal Community structure. The replacement of species and structural-attribute variation furnished evidence for the occurrence of two successional phases (early and advanced) over 30 d of periphyton colonisation in both climatic periods. These successional stages were distinguished primarily by the species composition and successional trajectory. On a seasonal scale, the availability of light and nutrients were the factors that determined the organisation of the periphyton Community. In conclusion, the duration of the successional phases and species trajectory during periphyton colonisation was influenced by seasonality (allogenic factors) and differential species performance (autogenic factors) in a shallow tropical reservoir.

  • Effect of N and P enrichment on periphytic Algal Community succession in a tropical oligotrophic reservoir
    Limnology, 2012
    Co-Authors: Carla Ferragut, Denise Bicudo
    Abstract:

    This enrichment experiment was conducted to evaluate how nutrient availability drives colonization and succession of a periphytic Algal Community in a Brazilian tropical oligotrophic reservoir. Four treatments were designed using enclosures ( n  = 3): control (no nutrient addition), P+ (isolated phosphorus addition, N-limiting condition); N+ (isolated nitrogen addition, P-limiting condition), and NP+ (phosphorus and nitrogen combined addition, no limitation). Glass microscope slides were used for periphyton growth. Samplings were carried out at short, regular intervals (3–5 days) over 31 days. Isolated P addition promoted the highest structural organization, and both NP+ and P+ promoted the highest biomass accrual. Control condition favored Chromulina elegans (chrysophyte) dominance, whereas enrichment favored different species descriptors belonging mainly to cyanobacteria (N+) and green algae (P+, NP+). Phosphorus was the main environmental driver in the Community structural changes. All periphyton attributes were significantly affected by enrichments in the advanced successional stages, when species were strongly associated to different amendments. Periphytic Algal Community was quite sensitive to enrichments, allowing identification of successional sequences in each treatment; however, colonization time is relevant when monitoring strategies are considered.

Liliana Rodrigues - One of the best experts on this subject based on the ideXlab platform.

  • Periphytic Algal Community in lentic environments of the Upper Paraná River floodplain: seasonal and spatial variation
    Acta Limnologica Brasiliensia, 2018
    Co-Authors: Kisay Lorena Adame Montoya, Barbara Dunck, Liliana Rodrigues
    Abstract:

    Abstract Aim: This study aimed to evaluate the influence of the seasonal variation in the hydrological regime and of limnological variables on species richness of periphytic algae in lakes of the Upper Parana River floodplain. Methods: The study area is located in the last undammed stretch of the Parana River in this floodplain, in which three lakes were sampled quarterly (May, August and November 2014, and February and May 2015) for one year. The periphytic material was obtained from petioles of the aquatic macrophyte Eichhornia azurea (Sw.) Kunth. Results: We registered 149 taxa of periphytic algae, distributed in 9 classes. Algae richness changed as a function of the seasonal dynamics of the Parana River hydrological regime. Water level fluctuations directly influenced periphytic algae species, and during periods of high water level, there was also an increase in species richness. The limnological variables showed a close relationship with the hydrological regime, and the assimilable nutrients and turbidity were the abiotic factors that most influenced the Algal Community. The following species were present in all lakes: Fragilaria capucina Desmazieres, Gomphonema gracile Ehrenberg and Navicula cryptotenella Lange-Bertalot (Bacillariophyceae) and two species of the genus Oedogonium (Oedogoniophyceae). Conclusion: The hydrological regime of the Parana River played an important role in structuring the periphytic algae, and together with temporal variations of the limnological variables, influenced the species richness of these organisms in these floodplain lakes.

  • Periphytic Algal Community in lentic environments of the Upper Paraná River floodplain: seasonal and spatial variation
    2018
    Co-Authors: Kisay Lorena Adame, Barbara Dunck, Liliana Rodrigues
    Abstract:

    Abstract Aim: This study aimed to evaluate the influence of seasonal variation in the hydrological regime and of limnological variables on species richness of periphytic algae in lakes of the Upper Paraná River floodplain. Methods The study area is located in the last undammed stretch of the Paraná River in this floodplain, in which three lakes were sampled quarterly (May, August and November 2014, and February and May 2015) for one year. The periphytic material was obtained from petioles of the aquatic macrophyte Eichhornia azurea (Sw.) Kunth. Results We registered 149 taxa of periphytic algae, distributed in 9 classes. Algal richness changed as a function of the seasonal dynamics of the Paraná River’s hydrological regime. Water level fluctuations directly influenced periphytic algae species. During periods of high water level, species richness increased. Limnological variables showed a close relationship with the hydrological regime, and the dissolved nutrients and turbidity were the abiotic factors that most influenced the Algal Community. The following species were present in all lakes: Fragilaria capucina Desmazières, Gomphonema gracile Ehrenberg and Navicula cryptotenella Lange-Bertalot (Bacillariophyceae) and two species of the genus Oedogonium (Oedogoniophyceae). Conclusions The hydrological regime of the Paraná River played an important role in structuring communities of periphytic algae. Seasonal variation in hydrological regime and in limnological variables together influenced the species richness of these organisms in these floodplain lakes.

  • Seasonal dynamics of the structure of epiphytic Algal Community on different substrates from a Neotropical floodplain
    Brazilian Journal of Botany, 2013
    Co-Authors: Érika Maria Neif, Rômulo Diego Lima Behrend, Liliana Rodrigues
    Abstract:

    This study aimed at analyzing the structure of epiphytic Algal Community on aquatic macrophytes morphologically different and in distinct hydrological periods at a lentic environment (Pombas Lake) located in the Upper Paraná River floodplain. In this study we tested the hypothesis that epiphyton richness, diversity, density, and composition, associated with submerged macrophytes are affected by hydrological dynamics and by habitat heterogeneity. The macrophytes used as substrates were Eichhornia azurea Kunth, an emergent macrophyte, and Egeria najas Planch, a submerged macrophyte. The samplings were performed quarterly in 2009, the species richness, diversity, density, and composition of the epiphytic Algal Community were evaluated. The species richness was not different between the substrates. Regardless of the evaluated substrate, the month of March had the highest species richness and diversity, especially of Desmids and Chlorophyceae. E. najas recorded the greater variation in abundance, compared with E. azurea . Bacillariophyceae, independent of the period and substrate, represented over 50 % of total density. The species composition was different among the periods, in which March and June (low water) were more similar and formed the group I, while September and December (high water) formed the group II. In summary, the hypothesis was accepted, since we verified that the hydrological dynamics of the floodplain is the direct controlling factor on structure of epiphytic Algal Community, and the substrate heterogeneity is the indirect controlling factor.

  • Periphytic Algal Community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil)
    Acta Scientiarum. Biological Sciences, 2010
    Co-Authors: Sirlene Aparecida Felisberto, Liliana Rodrigues
    Abstract:

    Periphytic Algal Community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). This study evaluated the heterogeneity in periphytic Algal Community, under the influence of time colonization on artificial substratum. We also examined which abiotic variables most influenced the Community in natural and artificial substratum. Egeria najas Planchon was used as natural substratum, and a plastic plant, as artificial. This experiment was carried out in a lateral arm from Rosana Reservoir, formed by Corvo Stream (Paranapanema river basin), in the period from November 21st to December 12nd, 2003, characterized as a warm and rainy period. Changes in species composition were assessed using the similarity indices. 495 taxa were registered in the phycoperiphytic Community, distributed in 133 genera and 11 classes. Zygnemaphyceae, Bacillariophyceae, Chlorophyceae and Cyanophyceae presented higher species number, in both substrata. Staurodesmus, Closterium, Staurastrum and Cosmarium (Desmidiales); Gomphonema and Eunotia (Pennales); Characium, Scenedesmus and Desmodesmus (Chlorococcales); Anabaena and Aphanocapsa (Nostocales and Chroococcales, respectively) were the most species-rich genera. The epiphytic Community reached the highest species richness in the 15th successional day. Regardless the substratum type, the number of species was probably related to the high concentrations of nutrients (phosphorus and nitrogen).Periphytic Algal Community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Paraná State, Brazil). This study evaluated the heterogeneity in periphytic Algal Community, under the influence of time colonization on artificial substratum. We also examined which abiotic variables most influenced the Community in natural and artificial substratum. Egeria najas Planchon was used as natural substratum, and a plastic plant, as artificial. This experiment was carried out in a lateral arm from Rosana Reservoir, formed by Corvo Stream (Paranapanema river basin), in the period from November 21st to December 12nd, 2003, characterized as a warm and rainy period. Changes in species composition were assessed using the similarity indices. 495 taxa were registered in the phycoperiphytic Community, distributed in 133 genera and 11 classes. Zygnemaphyceae, Bacillariophyceae, Chlorophyceae and Cyanophyceae presented higher species number, in both substrata. Staurodesmus, Closterium, Staurastrum and Cosmarium (Desmidiales); Gomphonema and Eunotia (Pennales); Characium, Scenedesmus and Desmodesmus (Chlorococcales); Anabaena and Aphanocapsa (Nostocales and Chroococcales, respectively) were the most species-rich genera. The epiphytic Community reached the highest species richness in the 15th successional day. Regardless the substratum type, the number of species was probably related to the high concentrations of nutrients (phosphorus and nitrogen)

  • periphytic Algal Community in artificial and natural substratum in a tributary of the rosana reservoir corvo stream parana state brazil
    Acta Scientiarum. Biological Sciences, 2010
    Co-Authors: Sirlene Aparecida Felisberto, Liliana Rodrigues
    Abstract:

    Periphytic Algal Community in artificial and natural substratum in a tributary of the Rosana reservoir (Corvo Stream, Parana State, Brazil). This study evaluated the heterogeneity in periphytic Algal Community, under the influence of time colonization on artificial substratum. We also examined which abiotic variables most influenced the Community in natural and artificial substratum. Egeria najas Planchon was used as natural substratum, and a plastic plant, as artificial. This experiment was carried out in a lateral arm from Rosana Reservoir, formed by Corvo Stream (Paranapanema river basin), in the period from November 21 st to December 12 nd , 2003, characterized as a warm and rainy period. Changes in species composition were assessed using the similarity indices. 495 taxa were registered in the phycoperiphytic Community, distributed in 133 genera and 11 classes. Zygnemaphyceae, Bacillariophyceae, Chlorophyceae and Cyanophyceae presented higher species number, in both substrata. Staurodesmus, Closterium, Staurastrum and Cosmarium (Desmidiales); Gomphonema and Eunotia (Pennales); Characium, Scenedesmus and Desmodesmus (Chlorococcales); Anabaena and Aphanocapsa (Nostocales and Chroococcales, respectively) were the most species-rich genera. The epiphytic Community reached the highest species richness in the 15 th successional day. Regardless the substratum type, the number of species was probably related to the high concentrations of nutrients (phosphorus and nitrogen).

Merritt R. Turetsky - One of the best experts on this subject based on the ideXlab platform.

  • Spatial and temporal variability of Algal Community dynamics and productivity in floodplain wetlands along the Tanana River, Alaska
    Freshwater Science, 2014
    Co-Authors: Allison R. Rober, Kevin H. Wyatt, R. Jan Stevenson, Merritt R. Turetsky
    Abstract:

    AbstractThe boreal landscape is a mosaic of wetlands with distinct ecosystem properties. Algae are important for wetland functioning, but relatively little is known about the structure of Algal communities among boreal wetlands. We documented spatial and temporal variability of Algal Community dynamics and productivity during a growing season in 6 wetlands (1 rich and 1 poor fen, 1 tussock, and 3 riverine marshes) in interior Alaska. Algal biomass and productivity were greater in the poor fen and a riverine marsh than in all other wetlands. Water depth and nutrients were significant predictors of benthic Algal biomass and productivity among wetlands and were greatest immediately after the spring thaw and decreased during the growing season. Water depth and nutrients (N and P) explained the most variability in Algal Community structure. Algal Community structure differed among wetlands, and temporal variation in environmental conditions was a significant predictor of the relative abundance of Algal genera ...

  • Algal Community response to experimental and interannual variation in hydrology in an Alaskan boreal fen
    Freshwater Science, 2013
    Co-Authors: Allison R. Rober, Kevin H. Wyatt, Merritt R. Turetsky, R. Jan Stevenson
    Abstract:

    Floristic studies indicate the abundance of microalgae in northern boreal peatlands, but we know relatively little about their ecology or how they will respond to changes in environmental conditions expected in this region as climate changes. We examined changes in Algal Community structure at sites exposed to a long-term water-table manipulation, including drought (lowered water-table treatment), flooding (raised water-table treatment), and control (no manipulation) treatments in an Alaskan fen. In previous years, continuous Algal colonization typically would have occurred only in the raised water-table treatment, but a spring flood inundated experimental plots and provided a unique opportunity to examine Algal Community response to rewetting after long-term drought. This event allowed us to investigate how much ecosystem memory of the antecedent water-table manipulations regulated the ability of taxa to recolonize sites after prolonged drought compared to sites that had been continuously flooded. Despite no differences in water-table position among treatments at the time of sampling, surface-water nutrient concentrations were higher in the lowered water-table treatment relative to the other treatments after the spring thaw. This difference corresponded with greater Algal abundance and biovolume in the lowered water-table treatment relative to the control and raised water-table treatments. Higher abundance and biovolume was driven mainly by filamentous green algae (Chlorophyta), especially Oedogonium, Spirogyra, and Microspora. Diatoms were most abundant in the raised water-table treatment, whereas chrysophytes were most abundant in the control treatment. Across all water-table treatments, N-fixing cyanobacteria increased as nutrients and water-table position declined over time. The differences in Algal Community structure among water-table treatments suggest that alternating drought and flooding events expected with climate change may significantly alter Algal-driven functions in boreal wetlands.

  • the importance of nutrient co limitation in regulating Algal Community composition productivity and Algal derived doc in an oligotrophic marsh in interior alaska
    Freshwater Biology, 2010
    Co-Authors: Kevin H. Wyatt, Jan R. Stevenson, Merritt R. Turetsky
    Abstract:

    Summary 1. Compared to lakes and streams, we know relatively little about the factors that regulate algae in freshwater wetlands. This discrepancy is particularly acute in boreal regions, where wetlands are abundant and processes related to climate change (i.e. increased permafrost collapse and soil weathering) are expected to increase nutrient inputs into aquatic systems. To investigate how accelerated nutrient inputs might affect Algal structure and function in northern boreal wetlands, we added nitrogen, phosphorus and silica to mesocosms in an oligotrophic marsh in interior Alaska. 2. We conducted two in situ mesocosm enrichment experiments during consecutive summer growing seasons, each lasting 24 days. In 2007, we investigated the effects of +N, +P, +Si and +N+P+Si enrichment on benthic Algal biomass (chlorophyll-a, ash-free dry mass, biovolume), chemistry (N : P ratio) and Community composition. In 2008, we expanded our first experiment to investigate the effects +N+P, +N+Si, +P+Si and +N+P+Si on the same Algal parameters as well as productivity (mg C m−2 h−1). 3. In both experiments, we measured water-column dissolved organic carbon (DOC) inside treatment enclosures and related changes in DOC to standing Algal biomass. 4. Benthic Algal accrual did not increase following 24 days of enrichment with any nutrient alone or with P and Si together (+P+Si), but increased significantly with the addition of N in any combination with P and Si (+N+P, +N+Si, +N+P+Si). 5. Algal productivity (20 mg C m−2 h−1) increased between three- and seven-fold (57–127 mg C m−2 h−1) with the addition of N in combination with any other nutrient (+N+P, +N+Si, +N+P+Si). Water-column DOC concentration was significantly higher inside N-combination treatments compared to the control during each season, and DOC increased linearly with benthic Algal biomass in 2007 (r2 = 0.89, P < 0.0001) and 2008 (r2 = 0.74, P < 0.0001). 6. Taxonomic composition of the wetland Algal Community responded most strongly to N-combination treatments in both seasons. In 2007, there was a significant shift from Euglena and Mougeotia in the control treatment to Chroococcus and Gloeocystis with +N+P+Si enrichment, and in 2008, a Mougeotia-dominated Community was replaced by Gloeocystis in the +N+P treatment and by Nitzschia in +N+Si and +N+P+Si treatments. 7. Together, these data provide several lines of evidence for co-limitation, and the central importance of N as a co-limiting nutrient for the wetland Algal Community. Changes in Algal dynamics with increased nutrient concentrations could have important implications for wetland food webs and suggest that algae may provide a functional link between increasing nutrient inputs and altered wetland carbon cycling in this region.

Mariane Lima De Souza - One of the best experts on this subject based on the ideXlab platform.

  • periphytic Algal Community structure in relation to seasonal variation and macrophyte richness in a shallow tropical reservoir
    Hydrobiologia, 2015
    Co-Authors: Mariane Lima De Souza, Barbara Golebski Pellegrini, Carla Ferragut
    Abstract:

    The macrophyte structure can influence the development of periphytic Algal Community in a shallow ecosystem. We investigated the interrelationship between periphytic Algal Community on artificial substrate and macrophyte species richness during four seasons in a tropical shallow reservoir. The periphyton was evaluated by biomass (as AFDM), Algal abundance, species composition, and species richness. Limnological variables and macrophyte coverage were determined at sites with different macrophytes richness in littoral zone. Glass slides were used as the substrate and colonization time was 30 days. Periphytic Algal structure was significantly influenced by seasonality and macrophyte richness, as well as the interaction of two factors. Periphytic Algal density on natural and artificial substrates was negatively correlated with macrophyte richness and coverage. High biomass, Algal biovolume and dominance of Zygnemaphyceae occurred when there was an increase of Utricularia foliosa coverage (summer). Our results showed that the seasonality, and to a lesser extent macrophyte species richness, explained significant portion of the variability of periphyton biomass, Algal abundance, and taxonomic composition on artificial substrate. The changes in macrophyte Community may have direct consequences on the periphyton structure in a shallow tropical reservoir.

Quanfa Zhang - One of the best experts on this subject based on the ideXlab platform.

  • the responses of epilithic Algal Community structure and function to light and nutrients and their linkages in subtropical rivers
    Hydrobiologia, 2020
    Co-Authors: Jian Zhang, Xiao Shu, Yongyong Zhang, Xiang Tan, Quanfa Zhang
    Abstract:

    Epilithic Algal Community structure and function are important indicators of stream ecosystem health and are sensitive to ambient environmental changes. In this study, we examined the impact of light and nutrients on epilithic Algal Community structure and function by an in situ nutrient addition and shaded canopy experiment in subtropical streams in China. Epilithic algae structure, dominated by diatoms, was significantly different with nutrient addition and light reduction. Nutrient addition increased the epilithic algae and diatom density, colonial life-forms, planktonic diatoms, and high-profile diatoms but decreased the low-profile diatoms. The shaded canopy increased the low-profile diatoms but decreased the adnate life-forms, planktonic diatoms, and high-profile diatoms. Epilithic metabolism, including gross primary production (GPP), net daily metabolism (NDM), and production/respiration (P/R) increased with nutrient addition, while respiration (R) only increased when the canopy was open with nutrient addition. Epilithic GPP had a significant positive correlation with diatom density (P < 0.01, R2 = 0.9425). Our results indicated that changes in epilithic algae structure due to changes in riparian canopy coverage and nutrients could affect epilithic Algal Community function. Quantifying the impacts of such drivers on Community structure and function is vital to effective river management.

  • The responses of epilithic Algal Community structure and function to light and nutrients and their linkages in subtropical rivers
    Hydrobiologia, 2019
    Co-Authors: Jian Zhang, Xiao Shu, Yongyong Zhang, Tan Xiang, Quanfa Zhang
    Abstract:

    Epilithic Algal Community structure and function are important indicators of stream ecosystem health and are sensitive to ambient environmental changes. In this study, we examined the impact of light and nutrients on epilithic Algal Community structure and function by an in situ nutrient addition and shaded canopy experiment in subtropical streams in China. Epilithic algae structure, dominated by diatoms, was significantly different with nutrient addition and light reduction. Nutrient addition increased the epilithic algae and diatom density, colonial life-forms, planktonic diatoms, and high-profile diatoms but decreased the low-profile diatoms. The shaded canopy increased the low-profile diatoms but decreased the adnate life-forms, planktonic diatoms, and high-profile diatoms. Epilithic metabolism, including gross primary production (GPP), net daily metabolism (NDM), and production/respiration (P/R) increased with nutrient addition, while respiration (R) only increased when the canopy was open with nutrient addition. Epilithic GPP had a significant positive correlation with diatom density (P