2023
Rose, JP; Kupferberg, SJ; Peek, RA; Ashton, D; Bettaso, JB; Bobzien, S; Bourque, RM; Breedveld, KGH; Catenazzi, A; Drennan, JE; Gonsolin, E; Grefsrud, M; Herman, AE; House, MR; Kluber, MR; Lind, AJ; Marlow, KR; Striegle, A; Hattem, M; Wheeler, CA; Wilcox, JT; Wiseman, KD; Halstead, BJ
Identifying drivers of population dynamics for a stream breeding amphibian using time series of egg mass counts Journal Article
In: Ecosphere, vol. 14, iss. 8, pp. e4645, 2023.
Abstract | Links | BibTeX | Tags: amphibian declines, amphibian populations, amphibians, Foothill yellow‐legged frog, population structure, stream ecosystems
@article{Rose2023,
title = {Identifying drivers of population dynamics for a stream breeding amphibian using time series of egg mass counts},
author = {JP Rose and SJ Kupferberg and RA Peek and D Ashton and JB Bettaso and S Bobzien and RM Bourque and KGH Breedveld and A Catenazzi and JE Drennan and E Gonsolin and M Grefsrud and AE Herman and MR House and MR Kluber and AJ Lind and KR Marlow and A Striegle and M Hattem and CA Wheeler and JT Wilcox and KD Wiseman and BJ Halstead},
editor = {AM Kramer},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Ecosphere-2023-Rose.pdf},
doi = {10.1002/ecs2.4645},
year = {2023},
date = {2023-08-24},
urldate = {2023-08-24},
journal = {Ecosphere},
volume = {14},
issue = {8},
pages = {e4645},
abstract = {The decline in amphibian populations is one of the starkest examples of the biodiversity crisis. For stream breeding amphibians, alterations to natural flow regimes by dams, water diversions, and climate change have been implicated in declines and extirpations. Identifying drivers of amphibian declines requires long time series of abundance data because amphibian populations can exhibit high natural variability. Multiple population viability analysis (MPVA) models integrate abundance data and share information from different populations to estimate how environmental factors influence population growth. Flow alteration has been linked to declines and extirpations in the Foothill Yellow-legged Frog (Rana boylii), a stream breeding amphibian native to California and Oregon. To date, no study has jointly analyzed abundance data from populations throughout the range of R. boylii in an MPVA model. We compiled time series of egg mass counts (an index of adult female abundance) from R. boylii populations in 36 focal streams and fit an MPVA model to quantify how streamflow metrics, stream temperature, and surrounding land cover affect population growth. We found population growth was positively related to stream temperature and was higher in the years following a wet year with high total annual streamflow. Density dependence was weakest (i.e., carrying capacity was highest) for streams with high seasonality of streamflow and intermediate rates of change in streamflow during spring. Our results highlight how altered streamflow can further increase the risk of decline for R. boylii populations. Managing stream conditions to better match natural flow and thermal regimes would benefit the conservation of R. boylii populations.},
keywords = {amphibian declines, amphibian populations, amphibians, Foothill yellow‐legged frog, population structure, stream ecosystems},
pubstate = {published},
tppubtype = {article}
}
The decline in amphibian populations is one of the starkest examples of the biodiversity crisis. For stream breeding amphibians, alterations to natural flow regimes by dams, water diversions, and climate change have been implicated in declines and extirpations. Identifying drivers of amphibian declines requires long time series of abundance data because amphibian populations can exhibit high natural variability. Multiple population viability analysis (MPVA) models integrate abundance data and share information from different populations to estimate how environmental factors influence population growth. Flow alteration has been linked to declines and extirpations in the Foothill Yellow-legged Frog (Rana boylii), a stream breeding amphibian native to California and Oregon. To date, no study has jointly analyzed abundance data from populations throughout the range of R. boylii in an MPVA model. We compiled time series of egg mass counts (an index of adult female abundance) from R. boylii populations in 36 focal streams and fit an MPVA model to quantify how streamflow metrics, stream temperature, and surrounding land cover affect population growth. We found population growth was positively related to stream temperature and was higher in the years following a wet year with high total annual streamflow. Density dependence was weakest (i.e., carrying capacity was highest) for streams with high seasonality of streamflow and intermediate rates of change in streamflow during spring. Our results highlight how altered streamflow can further increase the risk of decline for R. boylii populations. Managing stream conditions to better match natural flow and thermal regimes would benefit the conservation of R. boylii populations.
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.