2011
Morris, Mark W. L.; Hondzo, Miki; Power, Mary E.
Scaling Glossosoma (Trichoptera) density by abiotic variables in mountain streams Journal Article
In: Journal of the North American Benthological Society, vol. 30, no. 2, pp. 493-506, 2011.
Abstract | Links | BibTeX | Tags: dimensional analysis, Froude number, Glossosoma, grazer, habitat., relative roughness
@article{Morris2011,
title = {Scaling Glossosoma (Trichoptera) density by abiotic variables in mountain streams},
author = {Mark W. L. Morris and Miki Hondzo and Mary E. Power},
url = {https://angelo.berkeley.edu/?attachment_id=2759},
doi = {10.1899/10-068.1},
year = {2011},
date = {2011-03-29},
journal = {Journal of the North American Benthological Society},
volume = {30},
number = {2},
pages = {493-506},
abstract = {The stream-dwelling larvae of the caddisfly Glossosoma spp. are dominant grazers in lotic food
webs and are capable of suppressing stream periphyton. We explored a method for developing a scaling
relationship between macroinvertebrate density and local hydraulic variables. As an example of this
method, we quantified habitat for larval stone-cased caddisflies, Glossosoma califica and Glossosoma penitum, in 3 coastal mountain streams in northern California over 2 y. We applied dimensional analysis to develop a functional relationship from a power law based on dimensionless local hydraulic and larval density variables that was applicable to areas where Glossosoma are present. Glossosoma densities were negatively correlated with streambed relative roughness and positively correlated with the ratio of inertial togravitational forces in the stream. The proposed functional relationship described 41% of the variance in the spatial distribution of glossosomatid larvae. This expression could predict how density and constraints on effects of these important grazers would change under variable hydraulic conditions. Variogram analysis of Glossosoma spatial density and relative roughness revealed overlap in the variogram range, the separation distance above which point measurements were statistically independent. The analysis resulted in an average variogram range of 0.39 m for Glossosoma density and 0.26 m for roughness height. Abiotic variables are increasingly available from laser altimetry, so even where field sampling is limited the proposed scaling relationship facilitates prediction of larval biomass over a range of scales in lotic ecosystems.},
keywords = {dimensional analysis, Froude number, Glossosoma, grazer, habitat., relative roughness},
pubstate = {published},
tppubtype = {article}
}
The stream-dwelling larvae of the caddisfly Glossosoma spp. are dominant grazers in lotic food
webs and are capable of suppressing stream periphyton. We explored a method for developing a scaling
relationship between macroinvertebrate density and local hydraulic variables. As an example of this
method, we quantified habitat for larval stone-cased caddisflies, Glossosoma califica and Glossosoma penitum, in 3 coastal mountain streams in northern California over 2 y. We applied dimensional analysis to develop a functional relationship from a power law based on dimensionless local hydraulic and larval density variables that was applicable to areas where Glossosoma are present. Glossosoma densities were negatively correlated with streambed relative roughness and positively correlated with the ratio of inertial togravitational forces in the stream. The proposed functional relationship described 41% of the variance in the spatial distribution of glossosomatid larvae. This expression could predict how density and constraints on effects of these important grazers would change under variable hydraulic conditions. Variogram analysis of Glossosoma spatial density and relative roughness revealed overlap in the variogram range, the separation distance above which point measurements were statistically independent. The analysis resulted in an average variogram range of 0.39 m for Glossosoma density and 0.26 m for roughness height. Abiotic variables are increasingly available from laser altimetry, so even where field sampling is limited the proposed scaling relationship facilitates prediction of larval biomass over a range of scales in lotic ecosystems.
webs and are capable of suppressing stream periphyton. We explored a method for developing a scaling
relationship between macroinvertebrate density and local hydraulic variables. As an example of this
method, we quantified habitat for larval stone-cased caddisflies, Glossosoma califica and Glossosoma penitum, in 3 coastal mountain streams in northern California over 2 y. We applied dimensional analysis to develop a functional relationship from a power law based on dimensionless local hydraulic and larval density variables that was applicable to areas where Glossosoma are present. Glossosoma densities were negatively correlated with streambed relative roughness and positively correlated with the ratio of inertial togravitational forces in the stream. The proposed functional relationship described 41% of the variance in the spatial distribution of glossosomatid larvae. This expression could predict how density and constraints on effects of these important grazers would change under variable hydraulic conditions. Variogram analysis of Glossosoma spatial density and relative roughness revealed overlap in the variogram range, the separation distance above which point measurements were statistically independent. The analysis resulted in an average variogram range of 0.39 m for Glossosoma density and 0.26 m for roughness height. Abiotic variables are increasingly available from laser altimetry, so even where field sampling is limited the proposed scaling relationship facilitates prediction of larval biomass over a range of scales in lotic ecosystems.
2006
McNeely, C.; Clinton, S. M.; Erbe, J. M.
Landscape variation in C sources of scraping primary consumers in streams Journal Article
In: Journal of the North American Benthological Society, vol. 25, no. 4, pp. 787-799, 2006.
Abstract | Links | BibTeX | Tags: carbon source, diet, drainage area, Eel River drainage, epilithon, fine particulate organic matter, food web, Glossosoma, Heptageniidae, scrapers, Stable carbon isotopes
@article{McNeely2006,
title = {Landscape variation in C sources of scraping primary consumers in streams},
author = {C. McNeely and S. M. Clinton and J. M. Erbe},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/McNeely_2006_Benth.pdf},
doi = {10.1899/0887-3593(2006)025[0787:LVICSO]2.0.CO;2},
year = {2006},
date = {2006-01-01},
journal = {Journal of the North American Benthological Society},
volume = {25},
number = {4},
pages = {787-799},
abstract = {We studied variation in C and energy flow in stream food webs by examining primary consumer diets and potential food sources at 8 sites of different drainage areas in the South Fork Eel River drainage. Both heptageniid mayfly nymphs and Glossosoma caddisfly larvae are considered scrapers in traditional functional feeding group classification, but past studies suggested that they differed in their relative use of terrestrial and algal C in some streams. In our study, microscopic examination and stable C isotope ratios (δ13C) suggested an increasing contribution of algae to both epilithic biofilms and fine particulate organic matter as stream drainage area and productivity increased. The proportion of algal cells in biofilms of small, unproductive streams was low, and biofilm δ13C values were similar to those of terrestrial detritus, suggesting that biofilms were composed primarily of heterotrophic microorganisms. Glossosoma larvae fed selectively on algae where it was scarce within the biofilms of small forested streams. In contrast, heptageniid mayfly nymphs did not appear to feed selectively on algae, but consumed algae and other materials in proportion to their abundance in the environment. These feeding patterns may have consequences for energy flow through food webs. Heptageniid mayflies feeding on biofilms in unproductive streams may augment the flow of dissolved organic C from terrestrial sources through food webs. In contrast, selective feeding by abundant Glossosoma larvae may reduce the flow of algal C through food webs because they are resistant to aquatic predators.},
keywords = {carbon source, diet, drainage area, Eel River drainage, epilithon, fine particulate organic matter, food web, Glossosoma, Heptageniidae, scrapers, Stable carbon isotopes},
pubstate = {published},
tppubtype = {article}
}
We studied variation in C and energy flow in stream food webs by examining primary consumer diets and potential food sources at 8 sites of different drainage areas in the South Fork Eel River drainage. Both heptageniid mayfly nymphs and Glossosoma caddisfly larvae are considered scrapers in traditional functional feeding group classification, but past studies suggested that they differed in their relative use of terrestrial and algal C in some streams. In our study, microscopic examination and stable C isotope ratios (δ13C) suggested an increasing contribution of algae to both epilithic biofilms and fine particulate organic matter as stream drainage area and productivity increased. The proportion of algal cells in biofilms of small, unproductive streams was low, and biofilm δ13C values were similar to those of terrestrial detritus, suggesting that biofilms were composed primarily of heterotrophic microorganisms. Glossosoma larvae fed selectively on algae where it was scarce within the biofilms of small forested streams. In contrast, heptageniid mayfly nymphs did not appear to feed selectively on algae, but consumed algae and other materials in proportion to their abundance in the environment. These feeding patterns may have consequences for energy flow through food webs. Heptageniid mayflies feeding on biofilms in unproductive streams may augment the flow of dissolved organic C from terrestrial sources through food webs. In contrast, selective feeding by abundant Glossosoma larvae may reduce the flow of algal C through food webs because they are resistant to aquatic predators.