2022
Grant, G
Where’s water — now and in the future — in the Western US? Implications for forest management. Presentation
15.07.2022.
BibTeX | Tags: ERCZO, forested watershed
@misc{Grant2022,
title = {Where’s water — now and in the future — in the Western US? Implications for forest management.},
author = {G Grant},
year = {2022},
date = {2022-07-15},
issue = {USDA Forest Service ScienceX},
keywords = {ERCZO, forested watershed},
pubstate = {published},
tppubtype = {presentation}
}
2007
McNeeley, C; Finlay, JC; Power, ME
Grazer Traits, Competition, and Carbon Sources to a Headwater-Stream Food Web Journal Article
In: Ecology, vol. 88, iss. 2, pp. 391-401, 2007, ISBN: 0012-9658.
Abstract | Links | BibTeX | Tags: forested watershed
@article{McNeeley2007,
title = {Grazer Traits, Competition, and Carbon Sources to a Headwater-Stream Food Web},
author = {C McNeeley and JC Finlay and ME Power},
url = {http://www.esajournals.org/doi/abs/10.1890/0012-9658%282007%2988%5B391%3AGTCACS%5D2.0.CO%3B2},
doi = {10.1890/0012-9658(2007)88[391:GTCACS]2.0.CO;2},
isbn = {0012-9658},
year = {2007},
date = {2007-02-01},
urldate = {2007-02-01},
journal = {Ecology},
volume = {88},
issue = {2},
pages = {391-401},
abstract = {We investigated the effect of grazing by a dominant invertebrate grazer (the caddisfly Glossosoma penitum) on the energy sources used by other consumers in a headwater-stream food web. Stable isotope studies in small, forested streams in northern California have shown that G. penitum larvae derive most of their carbon from algae, despite low algal standing crops. We hypothesized that the caddisfly competes with other primary consumers (including mayflies) for algal food and increases their reliance on terrestrial detritus. Because Glossosoma are abundant and defended from predators by stone cases, their consumption of algal energy may reduce its transfer up the food chain. We removed Glossosoma (natural densities >1000 caddisflies/m2) from five (4 m2) stream sections during the summer of 2000 and measured responses of algae, invertebrate primary consumers, and invertebrate predators. The treatment reduced Glossosoma biomass by 80–90%. We observed a doubling in chlorophyll a per area in sections with reduced Glossosoma abundance and aggregative increases in the biomass of undefended primary consumers. Heptageniid mayfly larvae consumed more algae (as measured by stable carbon isotope ratios and gut content analysis) in caddisfly removal plots at the end of the 60-day experiment, although not after one month. We did not see isotopic evidence of increased algal carbon in invertebrate predators, however. Patterns of caddisfly and mayfly diets in the surrounding watershed suggested that mayfly diets are variable and include algae and detrital carbon in variable proportions, but scraping caddisflies consume primarily algae. Caddisfly and mayfly diets are more similar in larger, more productive streams where the mayflies assimilate more algae. Isotopic analysis, in combination with measurements of macroinvertebrate abundance and biomass in unmanipulated plots, suggested that a substantial portion of the invertebrate community (>50% of biomass) was supported, at least partially, by local algal carbon during midsummer. These data suggest that algae may be more important to community dynamics in headwater streams than their relatively low productivity would suggest. Through their high densities and relative invulnerability to predation, armored grazers may also affect community structure and flow of algal and detrital carbon in headwater streams.},
keywords = {forested watershed},
pubstate = {published},
tppubtype = {article}
}
We investigated the effect of grazing by a dominant invertebrate grazer (the caddisfly Glossosoma penitum) on the energy sources used by other consumers in a headwater-stream food web. Stable isotope studies in small, forested streams in northern California have shown that G. penitum larvae derive most of their carbon from algae, despite low algal standing crops. We hypothesized that the caddisfly competes with other primary consumers (including mayflies) for algal food and increases their reliance on terrestrial detritus. Because Glossosoma are abundant and defended from predators by stone cases, their consumption of algal energy may reduce its transfer up the food chain. We removed Glossosoma (natural densities >1000 caddisflies/m2) from five (4 m2) stream sections during the summer of 2000 and measured responses of algae, invertebrate primary consumers, and invertebrate predators. The treatment reduced Glossosoma biomass by 80–90%. We observed a doubling in chlorophyll a per area in sections with reduced Glossosoma abundance and aggregative increases in the biomass of undefended primary consumers. Heptageniid mayfly larvae consumed more algae (as measured by stable carbon isotope ratios and gut content analysis) in caddisfly removal plots at the end of the 60-day experiment, although not after one month. We did not see isotopic evidence of increased algal carbon in invertebrate predators, however. Patterns of caddisfly and mayfly diets in the surrounding watershed suggested that mayfly diets are variable and include algae and detrital carbon in variable proportions, but scraping caddisflies consume primarily algae. Caddisfly and mayfly diets are more similar in larger, more productive streams where the mayflies assimilate more algae. Isotopic analysis, in combination with measurements of macroinvertebrate abundance and biomass in unmanipulated plots, suggested that a substantial portion of the invertebrate community (>50% of biomass) was supported, at least partially, by local algal carbon during midsummer. These data suggest that algae may be more important to community dynamics in headwater streams than their relatively low productivity would suggest. Through their high densities and relative invulnerability to predation, armored grazers may also affect community structure and flow of algal and detrital carbon in headwater streams.
2006
O’Connor, B. L.; Hondzo, M.; Dobraca, D.; LaPara, T. M.; Finlay, J. C.; Brezonik, P. L.
Quantity-activity relationship of denitrifying bacteria and environmental scaling in streams of a forested watershed Journal Article
In: Journal of Geophysical Research, vol. 111, no. G4, pp. 1-13, 2006.
Abstract | Links | BibTeX | Tags: denitrifying bacteria, environmental scaling, forested watershed
@article{O'Connor2006,
title = {Quantity-activity relationship of denitrifying bacteria and environmental scaling in streams of a forested watershed},
author = {B. L. O'Connor and M. Hondzo and D. Dobraca and T. M. LaPara and J. C. Finlay and P. L. Brezonik},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/OConnor_2006_JourGeophysRes.pdf},
doi = {10.1029/2006JG000254},
year = {2006},
date = {2006-11-30},
journal = {Journal of Geophysical Research},
volume = {111},
number = {G4},
pages = {1-13},
abstract = {The spatial variability of subreach denitrification rates in streams was evaluated with respect to controlling environmental conditions, molecular examination of denitrifying bacteria, and dimensional analysis. Denitrification activities ranged from 0 and 800 ng-N gsed−1 d−1 with large variations observed within short distances (<50 m) along stream reaches. A log-normal probability distribution described the range in denitrification activities and was used to define low (16% of the probability distribution), medium (68%), and high (16%) denitrification potential groups. Denitrifying bacteria were quantified using a competitive polymerase chain reaction (cPCR) technique that amplified the nirK gene that encodes for nitrite reductase. Results showed a range of nirK quantities from 103 to 107 gene-copy-number gsed−1. A nonparametric statistical test showed no significant difference in nirK quantities among stream reaches, but revealed that samples with a high denitrification potential had significantly higher nirK quantities. Denitrification activity was positively correlated with nirK quantities with scatter in the data that can be attributed to varying environmental conditions along stream reaches. Dimensional analysis was used to evaluate denitrification activities according to environmental variables that describe fluid-flow properties, nitrate and organic material quantities, and dissolved oxygen flux. Buckingham's pi theorem was used to generate dimensionless groupings and field data were used to determine scaling parameters. The resulting expressions between dimensionless NO3− flux and dimensionless groupings of environmental variables showed consistent scaling, which indicates that the subreach variability in denitrification rates can be predicted by the controlling physical, chemical, and microbiological conditions.},
keywords = {denitrifying bacteria, environmental scaling, forested watershed},
pubstate = {published},
tppubtype = {article}
}
The spatial variability of subreach denitrification rates in streams was evaluated with respect to controlling environmental conditions, molecular examination of denitrifying bacteria, and dimensional analysis. Denitrification activities ranged from 0 and 800 ng-N gsed−1 d−1 with large variations observed within short distances (<50 m) along stream reaches. A log-normal probability distribution described the range in denitrification activities and was used to define low (16% of the probability distribution), medium (68%), and high (16%) denitrification potential groups. Denitrifying bacteria were quantified using a competitive polymerase chain reaction (cPCR) technique that amplified the nirK gene that encodes for nitrite reductase. Results showed a range of nirK quantities from 103 to 107 gene-copy-number gsed−1. A nonparametric statistical test showed no significant difference in nirK quantities among stream reaches, but revealed that samples with a high denitrification potential had significantly higher nirK quantities. Denitrification activity was positively correlated with nirK quantities with scatter in the data that can be attributed to varying environmental conditions along stream reaches. Dimensional analysis was used to evaluate denitrification activities according to environmental variables that describe fluid-flow properties, nitrate and organic material quantities, and dissolved oxygen flux. Buckingham’s pi theorem was used to generate dimensionless groupings and field data were used to determine scaling parameters. The resulting expressions between dimensionless NO3− flux and dimensionless groupings of environmental variables showed consistent scaling, which indicates that the subreach variability in denitrification rates can be predicted by the controlling physical, chemical, and microbiological conditions.
2001
Power, ME
Prey exchange between a stream and its forested watershed elevates predator densities in both habitats Journal Article
In: PNAS, vol. 98, iss. 1, pp. 14-15, 2001, ISBN: 0027-8424, 1091-6490.
Links | BibTeX | Tags: forested watershed, stream ecosystems
@article{Power2001f,
title = {Prey exchange between a stream and its forested watershed elevates predator densities in both habitats},
author = {ME Power},
url = {http://www.pnas.org/content/98/1/14},
doi = {10.1073/pnas.98.1.14},
isbn = {0027-8424, 1091-6490},
year = {2001},
date = {2001-01-02},
urldate = {2001-01-02},
journal = {PNAS},
volume = {98},
issue = {1},
pages = {14-15},
keywords = {forested watershed, stream ecosystems},
pubstate = {published},
tppubtype = {article}
}