2021
Bouma-Gregson, Keith; Power, Mary E.; Furey, Paula C.; Huckins, Casey J.; Vadeboncoeur, Yvonne
Taxon-specific photosynthetic responses of attached algal assemblages to experimental translocation between river habitats Journal Article
In: Freshwater Science, vol. 40, no. 1, 2021.
Abstract | Links | BibTeX | Tags: algae, benthic, Cladophora, cyanobacteria, electron transport rate, flow, Microcoleus, microhabitat, PAM, photosynthesis, temperature
@article{Bouma-Gregson2021,
title = {Taxon-specific photosynthetic responses of attached algal assemblages to experimental translocation between river habitats},
author = {Keith Bouma-Gregson and Mary E. Power and Paula C. Furey and Casey J. Huckins and Yvonne Vadeboncoeur},
url = {https://www.journals.uchicago.edu/doi/pdf/10.1086/713095},
doi = {10.1086/713095},
year = {2021},
date = {2021-02-25},
journal = {Freshwater Science},
volume = {40},
number = {1},
abstract = {Attached algal and cyanobacterial taxa differ in their ability to exploit and tolerate the diversity of flow, irradiance, and temperature regimes typical of a heterogeneous riverscape. Understanding the drivers of the small-scale variation in algal taxonomic composition helps us predict the riverscape-scale effects of altered flow regimes, but microhabitat-scale variation in algal taxonomy complicates the interpretation of ecosystem-scale estimates of biomass or primary production. Using pulse-amplitude modulated (PAM) fluorometry, we performed 2 manipulative field experiments (in 2014 and 2015) to measure photosynthetic responses of algae and cyanobacteria to depth, temperature, and flow modifications. In 2014, we exposed 6 attached algal assemblages common to the South Fork Eel River (California, USA) to a 24-h incubation on either the river bottom (20 cm deep) or floating at the water surface. In 2015, we incubated 3 algal assemblages for 1 wk in either the thalweg or at the river’s edge. For PAM measurements, we developed a novel method (Photosynthesis–Irradiance Periphyton Experimental System [PIPES]) for manipulating attached filamentous algae, a morphology common in aquatic habitats but underrepresented in photosynthesis experiments. To make the PIPES, we sandwiched thin (<1 mm) layers of filamentous attached algae between 2 layers of mesh so that the algae could be isolated and manipulated for repeated PAM measurements. In the 2014 experiment, incubating Cladophora, Rivularia, Microcoleus, and Anabaena at the water surface tended to decrease photosynthetic rates relative to submerged controls, whereas for Nostoc, the photosynthetic rates were higher in floating treatments. In the 2015 experiment, Cladophora and Oedogonium incubated in the warmer, low-flow river margin had persistently lower photosynthesis rates than their counterparts incubated in the thalweg. The PIPES method improves our ability to make PAM measurements on attached algae. PIPES can be used in conjunction with other methods to evaluate taxon-specific responses to environmental conditions and to help us predict how algal assemblages will shift in dominance under different river management regimes.},
keywords = {algae, benthic, Cladophora, cyanobacteria, electron transport rate, flow, Microcoleus, microhabitat, PAM, photosynthesis, temperature},
pubstate = {published},
tppubtype = {article}
}
Attached algal and cyanobacterial taxa differ in their ability to exploit and tolerate the diversity of flow, irradiance, and temperature regimes typical of a heterogeneous riverscape. Understanding the drivers of the small-scale variation in algal taxonomic composition helps us predict the riverscape-scale effects of altered flow regimes, but microhabitat-scale variation in algal taxonomy complicates the interpretation of ecosystem-scale estimates of biomass or primary production. Using pulse-amplitude modulated (PAM) fluorometry, we performed 2 manipulative field experiments (in 2014 and 2015) to measure photosynthetic responses of algae and cyanobacteria to depth, temperature, and flow modifications. In 2014, we exposed 6 attached algal assemblages common to the South Fork Eel River (California, USA) to a 24-h incubation on either the river bottom (20 cm deep) or floating at the water surface. In 2015, we incubated 3 algal assemblages for 1 wk in either the thalweg or at the river’s edge. For PAM measurements, we developed a novel method (Photosynthesis–Irradiance Periphyton Experimental System [PIPES]) for manipulating attached filamentous algae, a morphology common in aquatic habitats but underrepresented in photosynthesis experiments. To make the PIPES, we sandwiched thin (<1 mm) layers of filamentous attached algae between 2 layers of mesh so that the algae could be isolated and manipulated for repeated PAM measurements. In the 2014 experiment, incubating Cladophora, Rivularia, Microcoleus, and Anabaena at the water surface tended to decrease photosynthetic rates relative to submerged controls, whereas for Nostoc, the photosynthetic rates were higher in floating treatments. In the 2015 experiment, Cladophora and Oedogonium incubated in the warmer, low-flow river margin had persistently lower photosynthesis rates than their counterparts incubated in the thalweg. The PIPES method improves our ability to make PAM measurements on attached algae. PIPES can be used in conjunction with other methods to evaluate taxon-specific responses to environmental conditions and to help us predict how algal assemblages will shift in dominance under different river management regimes.
2020
Uno, Hiromi; Stillman, Jonathon H.
Lifetime eurythermy by seasonally matched thermal performance of developmental stages in an annual aquatic insect Journal Article
In: Oecologia, vol. 192, no. 3, pp. 647-656, 2020.
Abstract | Links | BibTeX | Tags: Aquatic insect, ERCZO, life cycle, season, STREAM, temperature
@article{Uno2020,
title = {Lifetime eurythermy by seasonally matched thermal performance of developmental stages in an annual aquatic insect},
author = {Hiromi Uno and Jonathon H. Stillman},
url = {https://angelo.berkeley.edu/oecologia-2020-uno/},
doi = {10.1007/s00442-020-04605-z},
year = {2020},
date = {2020-01-27},
urldate = {2020-01-27},
journal = {Oecologia},
volume = {192},
number = {3},
pages = {647-656},
abstract = {Organisms with annual life cycles are exposed to life stage specific thermal environments across seasons. Seasonal variation in thermal environments can vary across years and among sites. We investigated how organisms with annual life cycles respond to predictable seasonal changes in temperature and unpredictable thermal variation between habitats and years throughout their lives. Field surveys and historical records reveal that the spatially and temporally heterogeneous thermal environments
inhabited by the annual mayfly Ephemerella maculata (Ephemerellidae) shift the date for transition to the next, life stage, so that the thermal phenotype of each life stage matches the thermal environment of the specific habitat and year. Laboratory
studies of three distinct life stages of this mayfly reveal that life stage transitions are temperature dependent, facilitating timing shifts that are synchronized with the current season’s temperatures. Each life stage exhibited specific thermal sensitivity
and performance phenotypes that matched the ambient temperature typically experienced during that life stage. Our study across the whole life cycle reveals mechanisms that allow organisms to achieve lifetime eurythermy in a dynamic seasonal
environment, despite having narrower thermal ranges for growth and development in each life stage.},
keywords = {Aquatic insect, ERCZO, life cycle, season, STREAM, temperature},
pubstate = {published},
tppubtype = {article}
}
Organisms with annual life cycles are exposed to life stage specific thermal environments across seasons. Seasonal variation in thermal environments can vary across years and among sites. We investigated how organisms with annual life cycles respond to predictable seasonal changes in temperature and unpredictable thermal variation between habitats and years throughout their lives. Field surveys and historical records reveal that the spatially and temporally heterogeneous thermal environments
inhabited by the annual mayfly Ephemerella maculata (Ephemerellidae) shift the date for transition to the next, life stage, so that the thermal phenotype of each life stage matches the thermal environment of the specific habitat and year. Laboratory
studies of three distinct life stages of this mayfly reveal that life stage transitions are temperature dependent, facilitating timing shifts that are synchronized with the current season’s temperatures. Each life stage exhibited specific thermal sensitivity
and performance phenotypes that matched the ambient temperature typically experienced during that life stage. Our study across the whole life cycle reveals mechanisms that allow organisms to achieve lifetime eurythermy in a dynamic seasonal
environment, despite having narrower thermal ranges for growth and development in each life stage.
inhabited by the annual mayfly Ephemerella maculata (Ephemerellidae) shift the date for transition to the next, life stage, so that the thermal phenotype of each life stage matches the thermal environment of the specific habitat and year. Laboratory
studies of three distinct life stages of this mayfly reveal that life stage transitions are temperature dependent, facilitating timing shifts that are synchronized with the current season’s temperatures. Each life stage exhibited specific thermal sensitivity
and performance phenotypes that matched the ambient temperature typically experienced during that life stage. Our study across the whole life cycle reveals mechanisms that allow organisms to achieve lifetime eurythermy in a dynamic seasonal
environment, despite having narrower thermal ranges for growth and development in each life stage.
1997
Gresens, Susan E.
Interactive effects of diet and thermal regime on growth of the midge Pseudochironomus richardsoni Malloch Journal Article
In: Freshwater Biology, vol. 38, no. 2, pp. 365-373, 1997, ISSN: 0046-5070.
Abstract | Links | BibTeX | Tags: Blackwater River, diptera, larval chironomidae, rapid growth, Riparian, river food webs, SECONDARY PRODUCTION, size, STREAM, temperature
@article{Gresens1997,
title = {Interactive effects of diet and thermal regime on growth of the midge Pseudochironomus richardsoni Malloch},
author = {Susan E. Gresens},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Gresens_FreshwaterBiology1997.pdf},
doi = {10.1046/j.1365-2427.1997.00248.x},
issn = {0046-5070},
year = {1997},
date = {1997-10-00},
journal = {Freshwater Biology},
volume = {38},
number = {2},
pages = {365-373},
abstract = {1. Larvae of Pseudochironomus richardsoni were reared to pupation in individual enclosures, in one of three thermal habitats in a northern California stream. The average temperature range in cold seeps was 15-21 degrees C, while the main channel ranged from 20 to 27 degrees C, and side pools ranged from 18 to 33 degrees C. Diet consisted of either diatoms or algal detritus.
2. Specific growth rate ranged from 0.057 to 0.267 day(-1). Specific growth and developmental rates were highest on a diatom diet, and increased with temperature. Regressions of growth rate on mean microsite temperature were also significantly altered by diet. Differences in specific growth rate due to diet are magnified at higher temperatures.
3. Pupae reared on diatoms were larger than those reared on detritus. The mass of pupae reared on detritus decreased with increasing temperature. However, there was no significant relationship between pupal mass and temperature for larvae reared on diatoms.
4. The combined effects of food quality and thermal environment on growth of the midge P. richardsoni are significantly different from the independent effects of diet and temperature. Interactive effects of food quality and temperature may influence the contribution of certain aquatic habitats (algal mats) to invertebrate secondary production.},
keywords = {Blackwater River, diptera, larval chironomidae, rapid growth, Riparian, river food webs, SECONDARY PRODUCTION, size, STREAM, temperature},
pubstate = {published},
tppubtype = {article}
}
1. Larvae of Pseudochironomus richardsoni were reared to pupation in individual enclosures, in one of three thermal habitats in a northern California stream. The average temperature range in cold seeps was 15-21 degrees C, while the main channel ranged from 20 to 27 degrees C, and side pools ranged from 18 to 33 degrees C. Diet consisted of either diatoms or algal detritus.
2. Specific growth rate ranged from 0.057 to 0.267 day(-1). Specific growth and developmental rates were highest on a diatom diet, and increased with temperature. Regressions of growth rate on mean microsite temperature were also significantly altered by diet. Differences in specific growth rate due to diet are magnified at higher temperatures.
3. Pupae reared on diatoms were larger than those reared on detritus. The mass of pupae reared on detritus decreased with increasing temperature. However, there was no significant relationship between pupal mass and temperature for larvae reared on diatoms.
4. The combined effects of food quality and thermal environment on growth of the midge P. richardsoni are significantly different from the independent effects of diet and temperature. Interactive effects of food quality and temperature may influence the contribution of certain aquatic habitats (algal mats) to invertebrate secondary production.
2. Specific growth rate ranged from 0.057 to 0.267 day(-1). Specific growth and developmental rates were highest on a diatom diet, and increased with temperature. Regressions of growth rate on mean microsite temperature were also significantly altered by diet. Differences in specific growth rate due to diet are magnified at higher temperatures.
3. Pupae reared on diatoms were larger than those reared on detritus. The mass of pupae reared on detritus decreased with increasing temperature. However, there was no significant relationship between pupal mass and temperature for larvae reared on diatoms.
4. The combined effects of food quality and thermal environment on growth of the midge P. richardsoni are significantly different from the independent effects of diet and temperature. Interactive effects of food quality and temperature may influence the contribution of certain aquatic habitats (algal mats) to invertebrate secondary production.