2013
Simonin, Kevin A.; Link, Percy; Rempe, Daniella; Miller, Scot; Oshun, Jasper; Bode, Collin; Dietrich, William E.; Fung, Inez; Dawson, Todd E.
Vegetation induced changes in the stable isotope composition of near surface humidity Journal Article
In: Ecohydrology, vol. 7, no. 3, pp. 936–949, 2013.
Abstract | Links | BibTeX | Tags: ERCZO, humidity, stable isotope
@article{Simonin2013,
title = {Vegetation induced changes in the stable isotope composition of near surface humidity},
author = {Kevin A. Simonin and Percy Link and Daniella Rempe and Scot Miller and Jasper Oshun and Collin Bode and William E. Dietrich and Inez Fung and Todd E. Dawson},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Simonin_2013_Ecohydro.pdf},
doi = {10.1002/eco.1420},
year = {2013},
date = {2013-08-13},
urldate = {2013-08-13},
journal = {Ecohydrology},
volume = {7},
number = {3},
pages = {936–949},
abstract = {Obtaining the d-excess parameter from oxygen and hydrogen stable isotope composition of meteoric waters has the potential power to reconstruct changes in atmospheric water pools (e,g. sources, origins and overall balance) and the climatic conditions that prevail during surface evaporation. Recently, plant and ecosystem scientists turned their attention using d-excess information to inform questions at these scales. Here, we use the d-excess parameter to evaluate the influence of forest canopies on atmospheric humidity within a mixed evergreen forest in coastal California. We found that during the day, when transpiration was at a maximum, the d-excess of atmospheric water vapour exceeded model predictions for the background atmosphere into which the ecosystem evapotranspiration mixes. At night when transpiration was minor, the d-excess of atmospheric water vapour was on average less than model predictions for an ocean derived water vapour source. The observed diurnal fluctuations around the d-excess of the modelled background water vapour provided a strong evidence that during the day as the land surface warms and the boundary layer grows plants alter the isotope composition of atmospheric humidity via non-steady state isotope effects. In contrast, at night equilibrium isotope effects dominate as the atmosphere stabilizes. These day and nighttime fluctuations around the d-excess of ocean derived water vapour highlight the importance of plant transpiration for the isotope hydrology of near surface humidity and subsequently for the isotope composition of condensate like dew, an important water input to this ecosystem. Copyright © 2013 John Wiley & Sons, Ltd.},
keywords = {ERCZO, humidity, stable isotope},
pubstate = {published},
tppubtype = {article}
}
Obtaining the d-excess parameter from oxygen and hydrogen stable isotope composition of meteoric waters has the potential power to reconstruct changes in atmospheric water pools (e,g. sources, origins and overall balance) and the climatic conditions that prevail during surface evaporation. Recently, plant and ecosystem scientists turned their attention using d-excess information to inform questions at these scales. Here, we use the d-excess parameter to evaluate the influence of forest canopies on atmospheric humidity within a mixed evergreen forest in coastal California. We found that during the day, when transpiration was at a maximum, the d-excess of atmospheric water vapour exceeded model predictions for the background atmosphere into which the ecosystem evapotranspiration mixes. At night when transpiration was minor, the d-excess of atmospheric water vapour was on average less than model predictions for an ocean derived water vapour source. The observed diurnal fluctuations around the d-excess of the modelled background water vapour provided a strong evidence that during the day as the land surface warms and the boundary layer grows plants alter the isotope composition of atmospheric humidity via non-steady state isotope effects. In contrast, at night equilibrium isotope effects dominate as the atmosphere stabilizes. These day and nighttime fluctuations around the d-excess of ocean derived water vapour highlight the importance of plant transpiration for the isotope hydrology of near surface humidity and subsequently for the isotope composition of condensate like dew, an important water input to this ecosystem. Copyright © 2013 John Wiley & Sons, Ltd.
2007
Agrawal, A.; Ackerly, D. D.; Adler, F.; Arnold, B.; Caceres, C.; Doak, D. F.; Post, E.; Hudson, P.; Maron, J.; Mooney, K. A.; Power, M. E.; Schemske, D.; Stachowicz, J.; Strauss, S.; Turner, M. G.; Werner, E.
Filling key gaps in population and community ecology Journal Article
In: Frontiers in Ecology and the Environment, vol. 5, no. 3, pp. 145-152, 2007.
Abstract | Links | BibTeX | Tags: community, ecology, stable isotope
@article{Agrawal2007,
title = {Filling key gaps in population and community ecology},
author = {A. Agrawal and D. D. Ackerly and F. Adler and B. Arnold and C. Caceres and D. F. Doak and E. Post and P. Hudson and J. Maron and K. A. Mooney and M. E. Power and D. Schemske and J. Stachowicz and S. Strauss and M. G. Turner and E. Werner},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Agrawal_2007_FrontEcologyEnv.pdf},
doi = {10.1890/1540-9295(2007)5[145:FKGIPA]2.0.CO;2},
year = {2007},
date = {2007-04-01},
journal = {Frontiers in Ecology and the Environment},
volume = {5},
number = {3},
pages = {145-152},
abstract = {We propose research to fill key gaps in the areas of population and community ecology, based on a National Science Foundation workshop identifying funding priorities for the next 5–10 years. Our vision for the near future of ecology focuses on three core areas: predicting the strength and context-dependence of species interactions across multiple scales; identifying the importance of feedbacks from individual interactions to ecosystem dynamics; and linking pattern with process to understand species coexistence. We outline a combination of theory development and explicit, realistic tests of hypotheses needed to advance population and community ecology.},
keywords = {community, ecology, stable isotope},
pubstate = {published},
tppubtype = {article}
}
We propose research to fill key gaps in the areas of population and community ecology, based on a National Science Foundation workshop identifying funding priorities for the next 5–10 years. Our vision for the near future of ecology focuses on three core areas: predicting the strength and context-dependence of species interactions across multiple scales; identifying the importance of feedbacks from individual interactions to ecosystem dynamics; and linking pattern with process to understand species coexistence. We outline a combination of theory development and explicit, realistic tests of hypotheses needed to advance population and community ecology.
2005
Howard, J. K.; Cuffey, K. M.; Solomon, M.
In: Hydrobiologia, vol. 541, no. 1, pp. 229-236, 2005.
Abstract | Links | BibTeX | Tags: baseline conditions, California, freshwater mussels, stable isotope, trophic
@article{Howard2005,
title = {Toward using Margariitifera falcate as an indicator of base level nitrogen and carbon isotope ratios: insights from two California Coast Range rivers},
author = {J. K. Howard and K. M. Cuffey and M. Solomon},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Howard_2005_Hydrobio.pdf},
doi = {10.1007/s10750-004-5711-4},
year = {2005},
date = {2005-06-01},
journal = {Hydrobiologia},
volume = {541},
number = {1},
pages = {229-236},
abstract = {Measurements of freshwater mussel tissue are potentially very useful for determining base-level isotopic values for food web studies in aquatic environments. As long-lived, filter-feeding organisms, mussels have the potential to spatially and temporally average the isotopic baseline signal. Following from earlier studies that focused on lake environments, this study investigates the stable carbon and nitrogen isotope ratios in tissue of the river dwelling freshwater mussel, Margaritifera falcata, in two extensively studied northern California coast range rivers, the South Fork Eel and Navarro. We highlight advantages and challenges for using riverine mussel isotopes as indicators of baselines. δ13C of primary producers is known to vary with habitat along the South Fork Eel channel, but our measurements show no such variations, demonstrating that riverine mussels do preserve a spatially averaged measure of instream derived food sources. Mean δ13C and δ15N are shown to be markedly different in the two rivers, reflecting differences in food sources and possibly watershed land use. We also found that δ15N of mussel tissue increased by approximately 2‰ with mussel age in both rivers. This suggests it is important to consider age and size effects when estimating baseline values from mussel tissues.},
keywords = {baseline conditions, California, freshwater mussels, stable isotope, trophic},
pubstate = {published},
tppubtype = {article}
}
Measurements of freshwater mussel tissue are potentially very useful for determining base-level isotopic values for food web studies in aquatic environments. As long-lived, filter-feeding organisms, mussels have the potential to spatially and temporally average the isotopic baseline signal. Following from earlier studies that focused on lake environments, this study investigates the stable carbon and nitrogen isotope ratios in tissue of the river dwelling freshwater mussel, Margaritifera falcata, in two extensively studied northern California coast range rivers, the South Fork Eel and Navarro. We highlight advantages and challenges for using riverine mussel isotopes as indicators of baselines. δ13C of primary producers is known to vary with habitat along the South Fork Eel channel, but our measurements show no such variations, demonstrating that riverine mussels do preserve a spatially averaged measure of instream derived food sources. Mean δ13C and δ15N are shown to be markedly different in the two rivers, reflecting differences in food sources and possibly watershed land use. We also found that δ15N of mussel tissue increased by approximately 2‰ with mussel age in both rivers. This suggests it is important to consider age and size effects when estimating baseline values from mussel tissues.
2004
Finlay, Jacques C.
Patterns and controls of lotic algal stable isotope ratios Journal Article
In: Limnology and Oceanography, vol. 49, no. 3, pp. 850-861, 2004.
Abstract | Links | BibTeX | Tags: lotic algae, stable isotope
@article{Finlay2005,
title = {Patterns and controls of lotic algal stable isotope ratios},
author = {Jacques C. Finlay},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Finlay_2004_LimnOcean.pdf},
doi = {10.4319/lo.2004.49.3.0850},
year = {2004},
date = {2004-05-15},
journal = {Limnology and Oceanography},
volume = {49},
number = {3},
pages = {850-861},
abstract = {Spatial and temporal variations in stable carbon isotope ratios (i.e., δ13C) of primary producers are common but poorly understood features of isotopic characterizations of aquatic food webs. I investigated factors that control δ13C of algae (concentration and δ13C of inorganic carbon, algal fractionation, and growth rates) in riffle habitats across a gradient in stream size and productivity in northern California. There was considerable seasonal and spatial variation in δ13C of the green alga Cladophora glomerata, microalgal-influenced epilithic biofilms, and their herbivores. Algal and herbivore δ13C were depleted in 13C in small, unproductive tributary streams (−44‰ to −30‰) compared with more productive sites downstream (−31‰ to −23‰). The majority of variation in algal δ13C of Cladophora and epilithic biofilms was determined by dissolved CO2 (CO2aq) via effects on δ13C of CO2aq and photosynthetic fractionation. In contrast, two other taxa (the cyanobacterium Nostoc pruniforme and the red alga Lemanea sp.) showed little variation in δ13C or fractionation in response to varied inorganic carbon availability because of their distinct modes of inorganic carbon acquisition. Although variation in algal δ13C might complicate use of δ13C to resolve consumer diet sources under some circumstances, better understanding of such variation should improve the use of δ13C techniques in aquatic food web studies.},
keywords = {lotic algae, stable isotope},
pubstate = {published},
tppubtype = {article}
}
Spatial and temporal variations in stable carbon isotope ratios (i.e., δ13C) of primary producers are common but poorly understood features of isotopic characterizations of aquatic food webs. I investigated factors that control δ13C of algae (concentration and δ13C of inorganic carbon, algal fractionation, and growth rates) in riffle habitats across a gradient in stream size and productivity in northern California. There was considerable seasonal and spatial variation in δ13C of the green alga Cladophora glomerata, microalgal-influenced epilithic biofilms, and their herbivores. Algal and herbivore δ13C were depleted in 13C in small, unproductive tributary streams (−44‰ to −30‰) compared with more productive sites downstream (−31‰ to −23‰). The majority of variation in algal δ13C of Cladophora and epilithic biofilms was determined by dissolved CO2 (CO2aq) via effects on δ13C of CO2aq and photosynthetic fractionation. In contrast, two other taxa (the cyanobacterium Nostoc pruniforme and the red alga Lemanea sp.) showed little variation in δ13C or fractionation in response to varied inorganic carbon availability because of their distinct modes of inorganic carbon acquisition. Although variation in algal δ13C might complicate use of δ13C to resolve consumer diet sources under some circumstances, better understanding of such variation should improve the use of δ13C techniques in aquatic food web studies.
Finlay, Jacques C.
Patterns and controls of lotic algal stable isotope ratios Journal Article
In: Limnology and Oceanography, vol. 49, no. 3, pp. 850-861, 2004.
Abstract | Links | BibTeX | Tags: lotic algae, stable isotope
@article{Finlay2004,
title = {Patterns and controls of lotic algal stable isotope ratios},
author = {Jacques C. Finlay},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Patterns-and-controls-of-lotic-algal-stable-carbon-isotope-ratios_Finlay.pdf},
year = {2004},
date = {2004-05-00},
journal = {Limnology and Oceanography},
volume = {49},
number = {3},
pages = {850-861},
abstract = {Spatial and temporal variations in stable carbon isotope ratios (i.e., delta(13)C) of primary producers are common but poorly understood features of isotopic characterizations of aquatic food webs. I investigated factors that control delta(13)C of algae (concentration and delta(13)C of inorganic carbon, algal fractionation, and growth rates) in riffle habitats across a gradient in stream size and productivity in northern California. There was considerable seasonal and spatial variation in delta(13)C of the green alga Cladophora glomerata, microalgal-influenced epilithic biofilms, and their herbivores. Algal and herbivore delta(13)C were depleted in C-13 in small, unproductive tributary streams (-44parts per thousand to -30parts per thousand) compared with more productive sites downstream (-31parts per thousand to -23parts per thousand). The majority of variation in algal delta(13)C of Cladophora and epilithic biofilms was determined by dissolved CO2 (CO2aq) via effects on delta(13)C of CO2aq and photosynthetic fractionation. In contrast, two other taxa (the cyanobacterium Nostoc pruniforme and the red alga Lemanea sp.) showed little variation in delta(13)C or fractionation in response to varied inorganic carbon availability because of their distinct modes of inorganic carbon acquisition. Although variation in algal delta(13)C might complicate use of delta(13)C to resolve consumer diet sources under some circumstances, better understanding of such variation should improve the use of delta(13)C techniques in aquatic food web studies.},
keywords = {lotic algae, stable isotope},
pubstate = {published},
tppubtype = {article}
}
Spatial and temporal variations in stable carbon isotope ratios (i.e., delta(13)C) of primary producers are common but poorly understood features of isotopic characterizations of aquatic food webs. I investigated factors that control delta(13)C of algae (concentration and delta(13)C of inorganic carbon, algal fractionation, and growth rates) in riffle habitats across a gradient in stream size and productivity in northern California. There was considerable seasonal and spatial variation in delta(13)C of the green alga Cladophora glomerata, microalgal-influenced epilithic biofilms, and their herbivores. Algal and herbivore delta(13)C were depleted in C-13 in small, unproductive tributary streams (-44parts per thousand to -30parts per thousand) compared with more productive sites downstream (-31parts per thousand to -23parts per thousand). The majority of variation in algal delta(13)C of Cladophora and epilithic biofilms was determined by dissolved CO2 (CO2aq) via effects on delta(13)C of CO2aq and photosynthetic fractionation. In contrast, two other taxa (the cyanobacterium Nostoc pruniforme and the red alga Lemanea sp.) showed little variation in delta(13)C or fractionation in response to varied inorganic carbon availability because of their distinct modes of inorganic carbon acquisition. Although variation in algal delta(13)C might complicate use of delta(13)C to resolve consumer diet sources under some circumstances, better understanding of such variation should improve the use of delta(13)C techniques in aquatic food web studies.