2009
Kupferberg, Sarah; Lind, A.; Yarnell, S.; Mount, J.
In: Public Interest Energy Research Program: Final Project Report, 2009, (This is the final report. There is alternatively a progress report available.).
Abstract | Links | BibTeX | Tags: 2D hydraulic modeling, amphibian populations, Cladophora glomerata, FERC relicensing, pulse flow effects, Rana boylii, river regulation, tadpole swimming
@article{Kupferberg2009,
title = {Pulsed flow effects on the Foothill Yellow‐ Legged Frog (Rana boylii): Integration of empirical, experimental, and hydrodynamic modeling approaches (Final Report)},
author = {Sarah Kupferberg and A. Lind and S. Yarnell and J. Mount},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Kupferberg_2009_CEC.pdf},
doi = {CEC‐500‐2009‐002},
year = {2009},
date = {2009-08-01},
journal = {Public Interest Energy Research Program: Final Project Report},
abstract = {Four analytical approaches support the hypothesis that altered flow regimes, particularly spring and summer pulsed discharges, contribute to the decline of foothill yellow‐legged frogs (Rana boylii) in regulated rivers. (1) A review of literature and FERC re‐licensing reports indicates that egg masses are negatively affected by pulsed flows via scouring, or desiccation, if spawning occurs during spills that abruptly cease. Tadpole stranding was documented in several studies. Effects on young of the year and older life stages were equivocal. (2) Long‐term population monitoring in three watersheds shows that frequency and magnitude of pulsed flows that harm embryos and tadpoles are factors in determining adult population status. These effects are offset by 2‐3 years, representing the time to reproductive maturity in central and northern California. (3) Experiments illustrate that tadpoles seek refuge in the substrate as velocity increases, are not adapted for sustained swimming, and are swept downstream. Tadpoles confined to refugia face predation and energetic costs in terms of growth and development. (4) Simulations using River2D, a 2‐dimensional hydrodynamic model, show that velocity and depth conditions exceed tolerances of R. boylii egg masses and tadpoles during a range of pulsed flows. While meso‐scale suitability of near shore habitat was accurately predicted, error in modeled point velocities at egg locations arose from limitations in fine scale surveying of the large, poorly sorted, rock substrate. Management that avoids aseasonal flow fluctuations would benefit R. boylii, and other taxa, whose lifecycles are synchronous with the natural timing of runoff in Californiaʹs rivers.},
note = {This is the final report. There is alternatively a progress report available.},
keywords = {2D hydraulic modeling, amphibian populations, Cladophora glomerata, FERC relicensing, pulse flow effects, Rana boylii, river regulation, tadpole swimming},
pubstate = {published},
tppubtype = {article}
}
Four analytical approaches support the hypothesis that altered flow regimes, particularly spring and summer pulsed discharges, contribute to the decline of foothill yellow‐legged frogs (Rana boylii) in regulated rivers. (1) A review of literature and FERC re‐licensing reports indicates that egg masses are negatively affected by pulsed flows via scouring, or desiccation, if spawning occurs during spills that abruptly cease. Tadpole stranding was documented in several studies. Effects on young of the year and older life stages were equivocal. (2) Long‐term population monitoring in three watersheds shows that frequency and magnitude of pulsed flows that harm embryos and tadpoles are factors in determining adult population status. These effects are offset by 2‐3 years, representing the time to reproductive maturity in central and northern California. (3) Experiments illustrate that tadpoles seek refuge in the substrate as velocity increases, are not adapted for sustained swimming, and are swept downstream. Tadpoles confined to refugia face predation and energetic costs in terms of growth and development. (4) Simulations using River2D, a 2‐dimensional hydrodynamic model, show that velocity and depth conditions exceed tolerances of R. boylii egg masses and tadpoles during a range of pulsed flows. While meso‐scale suitability of near shore habitat was accurately predicted, error in modeled point velocities at egg locations arose from limitations in fine scale surveying of the large, poorly sorted, rock substrate. Management that avoids aseasonal flow fluctuations would benefit R. boylii, and other taxa, whose lifecycles are synchronous with the natural timing of runoff in Californiaʹs rivers.
2008
Power, Mary E.; Parker, Michael S.; Dietrich, William E.
Seasonal Reassembly of a River Food Web: Floods, Droughts, and Impacts of Fish Journal Article
In: Ecological Monographs, vol. 78, no. 2, pp. 263–282, 2008, ISSN: 0012-9615.
Abstract | Links | BibTeX | Tags: Cladophora glomerata, context dependency, effect sizes, flood scour, food chain length, interaction strength, Lavinia (Hesperoleucas) symmetricus, long-term studies, Mediterranean hydrologic regimes, Oncorhynchus mykiss, population, predator impacts
@article{Power2008,
title = {Seasonal Reassembly of a River Food Web: Floods, Droughts, and Impacts of Fish},
author = {Mary E. Power and Michael S. Parker and William E. Dietrich},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Power_2008_EcoMono.pdf
https://angelo.berkeley.edu/wp-content/uploads/sites/59/Power_FoodWebDrouFloodFish_EcoMono2008.pdf
https://angelo.berkeley.edu/wp-content/uploads/sites/59/Power_AppA_EcoMono2008.pdf
https://angelo.berkeley.edu/wp-content/uploads/sites/59/Power_AppB_EcoMono2008.pdf},
doi = {10.1890/06-0902.1},
issn = {0012-9615},
year = {2008},
date = {2008-05-01},
journal = {Ecological Monographs},
volume = {78},
number = {2},
pages = {263–282},
abstract = {Eighteen years of field observations and five summer field experiments in a coastal California river suggest that hydrologic regimes influence algal blooms and the impacts of fish on algae, cyanobacteria, invertebrates, and small vertebrates. In this Mediterranean climate, rainy winters precede the biologically active summer low-flow season. Cladophora glomerata, the filamentous green alga that dominates primary producer biomass during summer, reaches peak biomass during late spring or early summer. Cladophora blooms are larger if floods during the preceding winter attained or exceeded ‘‘bankfull discharge’’ (sufficient to mobilize much of the river bed, estimated at 120 m3/s). In 9 out of 12 summers preceded by large bed-scouring floods, the average peak height of attached Cladophora turfs equaled or exceeded 50 cm. In five out of six years when flows remained below bankfull, Cladophora biomass peaked at lower levels. Flood effects on algae were partially mediated through impacts on consumers in food webs. In three experiments that followed scouring winter floods, juvenile steelhead (Oncorhynchus mykiss) and roach (Lavinia (Hesperoleucas) symmetricus) suppressed certain insects and young-of-the-year fish fry, affecting persistence or accrual of algae positively or negatively, depending on the predator-specific vulnerabilities of primary consumers capable of suppressing algae during a given year. During two post-flood years, these grazers were more vulnerable to small predators (odonates and fish fry, which stocked steelhead always suppressed) than to experimentally manipulated, larger fish, which had adverse effects on algae in those years. During one post-flood year, all enclosed grazers capable of suppressing algae were consumed by steelhead, which therefore had positive effects on algae. During drought years, when no bed-scouring winter flows occurred, large armored caddisflies (Dicosmoecus gilvipes) were more abundant during the subsequent summer. In drought-year experiments, stocked fish had little or no influence on algal standing crops, which increased only when Dicosmoecus were removed from enclosures. Flood scour, by suppressing invulnerable grazers, set the stage for fish mediated effects on algae in this river food web. Whether these effects were positive or negative depended on the predator-specific vulnerabilities of primary consumers that dominated during a given summer.},
keywords = {Cladophora glomerata, context dependency, effect sizes, flood scour, food chain length, interaction strength, Lavinia (Hesperoleucas) symmetricus, long-term studies, Mediterranean hydrologic regimes, Oncorhynchus mykiss, population, predator impacts},
pubstate = {published},
tppubtype = {article}
}
Eighteen years of field observations and five summer field experiments in a coastal California river suggest that hydrologic regimes influence algal blooms and the impacts of fish on algae, cyanobacteria, invertebrates, and small vertebrates. In this Mediterranean climate, rainy winters precede the biologically active summer low-flow season. Cladophora glomerata, the filamentous green alga that dominates primary producer biomass during summer, reaches peak biomass during late spring or early summer. Cladophora blooms are larger if floods during the preceding winter attained or exceeded ‘‘bankfull discharge’’ (sufficient to mobilize much of the river bed, estimated at 120 m3/s). In 9 out of 12 summers preceded by large bed-scouring floods, the average peak height of attached Cladophora turfs equaled or exceeded 50 cm. In five out of six years when flows remained below bankfull, Cladophora biomass peaked at lower levels. Flood effects on algae were partially mediated through impacts on consumers in food webs. In three experiments that followed scouring winter floods, juvenile steelhead (Oncorhynchus mykiss) and roach (Lavinia (Hesperoleucas) symmetricus) suppressed certain insects and young-of-the-year fish fry, affecting persistence or accrual of algae positively or negatively, depending on the predator-specific vulnerabilities of primary consumers capable of suppressing algae during a given year. During two post-flood years, these grazers were more vulnerable to small predators (odonates and fish fry, which stocked steelhead always suppressed) than to experimentally manipulated, larger fish, which had adverse effects on algae in those years. During one post-flood year, all enclosed grazers capable of suppressing algae were consumed by steelhead, which therefore had positive effects on algae. During drought years, when no bed-scouring winter flows occurred, large armored caddisflies (Dicosmoecus gilvipes) were more abundant during the subsequent summer. In drought-year experiments, stocked fish had little or no influence on algal standing crops, which increased only when Dicosmoecus were removed from enclosures. Flood scour, by suppressing invulnerable grazers, set the stage for fish mediated effects on algae in this river food web. Whether these effects were positive or negative depended on the predator-specific vulnerabilities of primary consumers that dominated during a given summer.
- https://angelo.berkeley.edu/wp-content/uploads/sites/59/Power_2008_EcoMono.pdf
- https://angelo.berkeley.edu/wp-content/uploads/sites/59/Power_FoodWebDrouFloodFi[…]
- https://angelo.berkeley.edu/wp-content/uploads/sites/59/Power_AppA_EcoMono2008.p[…]
- https://angelo.berkeley.edu/wp-content/uploads/sites/59/Power_AppB_EcoMono2008.p[…]
- doi:10.1890/06-0902.1
2001
Marks, Jane C.; Power, Mary E.
Nutrient induced changes in the species composition of epiphytes on Cladophora glomerata Kuetz. (Chlorophyta) Journal Article
In: Hydrobiologia, vol. 450, pp. 187-196, 2001.
Abstract | Links | BibTeX | Tags: Cladophora glomerata, epiphytes, nutrients, species composition
@article{Marks2001,
title = {Nutrient induced changes in the species composition of epiphytes on Cladophora glomerata Kuetz. (Chlorophyta)},
author = {Jane C. Marks and Mary E. Power},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Marks_2001_Hydrobiologia.pdf},
doi = {10.1023/A:1017596927664},
year = {2001},
date = {2001-00-00},
journal = {Hydrobiologia},
volume = {450},
pages = {187-196},
abstract = {Cladophora glomerata is a widely distributed filamentous freshwater alga that hosts a complex microalgal epiphyte assemblage.We manipulated nutrients and epiphyte abundances to access their effects on epiphyte biomass, epiphyte species composition, and C. glomerata growth. C. glomerata did not grow in response to these manipulations. Similarly, nutrient and epiphyte removal treatments did not alter epiphyte biovolume. Epiphyte species composition, however, changed dramatically with nutrient enrichment. The epiphyte assemblage on unenriched C. glomerata was dominated by Epithemia sorex and Epithemia adnata, whereas the assemblage on enriched C. glomerata was dominated by Achnanthidium minutissimum, Nitzschia palea and Synedra spp. These results indicate that nutrients strongly structure epiphyte species composition. Interactions between C. glomerata and its epiphytes were not affected by epiphyte species composition in our experiment but may be when C. glomerata is actively growing.},
keywords = {Cladophora glomerata, epiphytes, nutrients, species composition},
pubstate = {published},
tppubtype = {article}
}
Cladophora glomerata is a widely distributed filamentous freshwater alga that hosts a complex microalgal epiphyte assemblage.We manipulated nutrients and epiphyte abundances to access their effects on epiphyte biomass, epiphyte species composition, and C. glomerata growth. C. glomerata did not grow in response to these manipulations. Similarly, nutrient and epiphyte removal treatments did not alter epiphyte biovolume. Epiphyte species composition, however, changed dramatically with nutrient enrichment. The epiphyte assemblage on unenriched C. glomerata was dominated by Epithemia sorex and Epithemia adnata, whereas the assemblage on enriched C. glomerata was dominated by Achnanthidium minutissimum, Nitzschia palea and Synedra spp. These results indicate that nutrients strongly structure epiphyte species composition. Interactions between C. glomerata and its epiphytes were not affected by epiphyte species composition in our experiment but may be when C. glomerata is actively growing.
1995
Bergey, E. A.; Boettiger, C. A.; Resh, V. H.
Effects of water velocity on the architecture and epiphytes of Cladophora glomerata (Chlorophyta) Journal Article
In: Journal of Phycology, vol. 31, no. 2, pp. 264-271, 1995.
Abstract | Links | BibTeX | Tags: Cladophora glomerata, epiphytes, water velocity
@article{Bergey1995b,
title = {Effects of water velocity on the architecture and epiphytes of Cladophora glomerata (Chlorophyta)},
author = {E. A. Bergey and C. A. Boettiger and V. H. Resh},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Bergey_1995_JourPhyc.pdf},
doi = {10.1111/j.0022-3646.1995.00264.x},
year = {1995},
date = {1995-04-00},
journal = {Journal of Phycology},
volume = {31},
number = {2},
pages = {264-271},
abstract = {The architecture of the filamentous green alga Cladophora glomerata (L.) Kütz. and the composition of this alga's epiphytes [primarily the diatoms Epithemia turgida (Ehrenb.) Kütz., Epithemia sorex Kütz., and Cocconeis pediculus Ehrenb.] were examined in different velocity regimes. After transferring algal-bearing cobbles among velocities, the effects of changes in velocity were also examined. Cladophora branching pattern did not initially differ among slow, medium, and fast velocities, indicating that stable water velocities did not affect branching pattern. Two weeks after cobble transfer, Cladophora in fast velocity had fragmented more (i.e. had fewer filaments and fewer branch points per length of filament and had a higher percentage of unbranched filaments) than Cladophora in slow velocity. Fragmentation was greatest in tufts moved from slow velocity, suggesting velocity-associated differences in susceptibility to breakage. Epiphytic assemblage composition differed among slow, medium, and fast velocities and between locations on the filament (base and apex). Cocconeis pediculus dominated where exposure to high velocity was greater (filament apices in medium and fast velocities), whereas the Epithemia spp. dominated where lower velocities occurred (filament bases in all velocities and apices in slow velocity). Two weeks after the cobble transfer, the translocated diatom assemblages had changed and the original pattern of diatom distribution was restored.},
keywords = {Cladophora glomerata, epiphytes, water velocity},
pubstate = {published},
tppubtype = {article}
}
The architecture of the filamentous green alga Cladophora glomerata (L.) Kütz. and the composition of this alga’s epiphytes [primarily the diatoms Epithemia turgida (Ehrenb.) Kütz., Epithemia sorex Kütz., and Cocconeis pediculus Ehrenb.] were examined in different velocity regimes. After transferring algal-bearing cobbles among velocities, the effects of changes in velocity were also examined. Cladophora branching pattern did not initially differ among slow, medium, and fast velocities, indicating that stable water velocities did not affect branching pattern. Two weeks after cobble transfer, Cladophora in fast velocity had fragmented more (i.e. had fewer filaments and fewer branch points per length of filament and had a higher percentage of unbranched filaments) than Cladophora in slow velocity. Fragmentation was greatest in tufts moved from slow velocity, suggesting velocity-associated differences in susceptibility to breakage. Epiphytic assemblage composition differed among slow, medium, and fast velocities and between locations on the filament (base and apex). Cocconeis pediculus dominated where exposure to high velocity was greater (filament apices in medium and fast velocities), whereas the Epithemia spp. dominated where lower velocities occurred (filament bases in all velocities and apices in slow velocity). Two weeks after the cobble transfer, the translocated diatom assemblages had changed and the original pattern of diatom distribution was restored.