2020
Dawson, T. E.; Hahm, W. J.; Crutchfield-Peters, K.
Digging deeper: what the critical zone perspective adds to the study of plant ecophysiology Journal Article
In: New Phytologist, vol. 226, no. 3, pp. 666-671, 2020.
Abstract | Links | BibTeX | Tags: Critical Zone, ERCZO, nutrients, plant ecophysiology, soil, water, weathered bedrock
@article{Dawson2020,
title = {Digging deeper: what the critical zone perspective adds to the study of plant ecophysiology},
author = {T. E. Dawson and W. J. Hahm and K. Crutchfield-Peters},
url = {https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.16410},
doi = {10.1111/nph.16410},
year = {2020},
date = {2020-01-08},
journal = {New Phytologist},
volume = {226},
number = {3},
pages = {666-671},
abstract = {The emergence of critical zone (CZ) science has provided an integrative platform for investigating plant ecophysiology in the context of landscape evolution, weathering and hydrology. The CZ lies between the top of the vegetation canopy and fresh, chemically unaltered bedrock and plays a pivotal role in sustaining life. We consider what the CZ perspective has recently brought to the study of plant ecophysiology. We specifically highlight novel research demonstrating the importance of the deeper subsurface for plant water and nutrient relations. We also point to knowledge gaps and research opportunities, emphasising, in particular, greater focus on the roles of deep, nonsoil resources and how those resources influence and coevolve with plants as a frontier of plant ecophysiological research.},
keywords = {Critical Zone, ERCZO, nutrients, plant ecophysiology, soil, water, weathered bedrock},
pubstate = {published},
tppubtype = {article}
}
The emergence of critical zone (CZ) science has provided an integrative platform for investigating plant ecophysiology in the context of landscape evolution, weathering and hydrology. The CZ lies between the top of the vegetation canopy and fresh, chemically unaltered bedrock and plays a pivotal role in sustaining life. We consider what the CZ perspective has recently brought to the study of plant ecophysiology. We specifically highlight novel research demonstrating the importance of the deeper subsurface for plant water and nutrient relations. We also point to knowledge gaps and research opportunities, emphasising, in particular, greater focus on the roles of deep, nonsoil resources and how those resources influence and coevolve with plants as a frontier of plant ecophysiological research.
2014
Hood, James M.; McNeely, Camille; Finlay, Jacques C.; Sterner, Robert W.
Selective feeding determines patterns of nutrient release by stream invertebrates Journal Article
In: Freshwater Science, vol. 33, no. 4, pp. 1093-1107, 2014, ISSN: 2161-9549.
Abstract | Links | BibTeX | Tags: nutrients, selective feeding, stream invertebrates
@article{Hood2014,
title = {Selective feeding determines patterns of nutrient release by stream invertebrates},
author = {James M. Hood and Camille McNeely and Jacques C. Finlay and Robert W. Sterner},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Hood_2014_FreshSci.pdf},
doi = {10.1086/678693},
issn = {2161-9549},
year = {2014},
date = {2014-09-19},
journal = {Freshwater Science},
volume = {33},
number = {4},
pages = {1093-1107},
abstract = {One common stoichiometric approach to predicting patterns of nutrient release (excretion + egestion) by animals in aquatic ecosystems is to base predictions on elemental mass-balance constrained by homeostatic maintenance. An easily measured resource composite (i.e., seston, epilithon, or leaf litter) often is used to represent ingested stoichiometry, but whether such a composite is a good indicator of food actually ingested is a relatively unexplored assumption. We examined the application of a stoichiometric model to the diets of 4 generalist stream invertebrates. We fed 3 trichopteran and 1 amphipod taxa rations consisting of cultured algae, stream epilithon, and several species of conditioned leaf litter. The rations ranged widely in C:N from 10 to 69 (molar) and in C: P from 165 to 3500. After a 2-d feeding period, we measured NH4+ and PO43- excretion, and C, N, and P egestion rates. The relationships observed between the stoichiometries of release and ration were unexpected. Total N: P release rates conformed to stoichiometric predictions for only 1 taxon. Excretion and egestion rates and ratios were generally similar across diets and rarely varied with ration stoichiometry. These patterns were the result of smaller-than-expected responses to leaf-litter rations, which were the most imbalanced relative to body stoichiometry. Analysis of the C:N stoichiometry of foregut material for 2 taxa showed selective ingestion of an N-rich fraction of leaf litter, in 1 case reducing an apparent 8.4:1 C:N imbalance between diet and body composition to 1.5:1. Our results show that selective feeding can reduce potential stoichiometric imbalances, altering patterns of nutrient release relative to expectations based on bulk-diet stoichiometry. Assuming that stream invertebrates consume materials stoichiometrically similar to a resource composite can obscure understanding of stoichiometric imbalances and the role of invertebrates in nutrient cycles.},
keywords = {nutrients, selective feeding, stream invertebrates},
pubstate = {published},
tppubtype = {article}
}
One common stoichiometric approach to predicting patterns of nutrient release (excretion + egestion) by animals in aquatic ecosystems is to base predictions on elemental mass-balance constrained by homeostatic maintenance. An easily measured resource composite (i.e., seston, epilithon, or leaf litter) often is used to represent ingested stoichiometry, but whether such a composite is a good indicator of food actually ingested is a relatively unexplored assumption. We examined the application of a stoichiometric model to the diets of 4 generalist stream invertebrates. We fed 3 trichopteran and 1 amphipod taxa rations consisting of cultured algae, stream epilithon, and several species of conditioned leaf litter. The rations ranged widely in C:N from 10 to 69 (molar) and in C: P from 165 to 3500. After a 2-d feeding period, we measured NH4+ and PO43- excretion, and C, N, and P egestion rates. The relationships observed between the stoichiometries of release and ration were unexpected. Total N: P release rates conformed to stoichiometric predictions for only 1 taxon. Excretion and egestion rates and ratios were generally similar across diets and rarely varied with ration stoichiometry. These patterns were the result of smaller-than-expected responses to leaf-litter rations, which were the most imbalanced relative to body stoichiometry. Analysis of the C:N stoichiometry of foregut material for 2 taxa showed selective ingestion of an N-rich fraction of leaf litter, in 1 case reducing an apparent 8.4:1 C:N imbalance between diet and body composition to 1.5:1. Our results show that selective feeding can reduce potential stoichiometric imbalances, altering patterns of nutrient release relative to expectations based on bulk-diet stoichiometry. Assuming that stream invertebrates consume materials stoichiometrically similar to a resource composite can obscure understanding of stoichiometric imbalances and the role of invertebrates in nutrient cycles.
Olhsson, Elizabeth H.
Capturing the Impact of Riverine Nutrient Delivery on Coastal Ocean Biogeochemistry PhD Thesis
U.C. Berkeley, 2014.
Abstract | Links | BibTeX | Tags: coast, nutrients, ocean biogeochemistry
@phdthesis{Olhsson2014b,
title = {Capturing the Impact of Riverine Nutrient Delivery on Coastal Ocean Biogeochemistry},
author = {Elizabeth H. Olhsson},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Olhsson_2014_UCBerkTheses.pdf},
year = {2014},
date = {2014-01-01},
school = {U.C. Berkeley},
abstract = {Rivers smaller than the Amazon tend to be excluded from earth system modeling efforts. Does it
matter? Do sub-grid-scale rivers have significant impacts on offshore primary productivity?
Using the Eel River in northern California, the river with the largest sediment yield per drainage
area in the continental United States, as a test case, this question is explored using two
approaches. First, a data-driven analysis of relevant time series taken on land, by buoy, and from
space, demonstrates very little evidence of direct impact of Eel River discharge on
contemporaneous coastal ocean primary productivity – but to the extent that that evidence exists,
it seems to occur during years of greatest river discharge. To further analyze mechanistic
drivers, a coupled mesoscale modeling framework unifying ocean, watershed and atmospheric
representations is formulated and run in hindcast over the 2002-2010 period. Monthly average
climatologies, interannual variabilities, and event-driven analysis of each year’s largest river
discharge are all examined for evidence of a river-ocean connection expressed through primary
production. Storm event-generated turbulence appears to dominate the primary productivity
during the winter months. The impact of the river seems to be largely independent of nutrient
load, because its dissolved nitrate is less than that of the coastal ocean. There is no evidence that
riverine delivery of gradually bioavailable detritus has a significant effect. Although a
sufficiently super-nitrous river shows the ability to sustain a plume-nutrient-driven-bloom even
at periods of extremely low flow, this is not currently a realistic scenario for the Eel River. The
possibility remains that another micronutrient not studied in the modeling framework, such as
iron, could be important to this system.},
keywords = {coast, nutrients, ocean biogeochemistry},
pubstate = {published},
tppubtype = {phdthesis}
}
Rivers smaller than the Amazon tend to be excluded from earth system modeling efforts. Does it
matter? Do sub-grid-scale rivers have significant impacts on offshore primary productivity?
Using the Eel River in northern California, the river with the largest sediment yield per drainage
area in the continental United States, as a test case, this question is explored using two
approaches. First, a data-driven analysis of relevant time series taken on land, by buoy, and from
space, demonstrates very little evidence of direct impact of Eel River discharge on
contemporaneous coastal ocean primary productivity – but to the extent that that evidence exists,
it seems to occur during years of greatest river discharge. To further analyze mechanistic
drivers, a coupled mesoscale modeling framework unifying ocean, watershed and atmospheric
representations is formulated and run in hindcast over the 2002-2010 period. Monthly average
climatologies, interannual variabilities, and event-driven analysis of each year’s largest river
discharge are all examined for evidence of a river-ocean connection expressed through primary
production. Storm event-generated turbulence appears to dominate the primary productivity
during the winter months. The impact of the river seems to be largely independent of nutrient
load, because its dissolved nitrate is less than that of the coastal ocean. There is no evidence that
riverine delivery of gradually bioavailable detritus has a significant effect. Although a
sufficiently super-nitrous river shows the ability to sustain a plume-nutrient-driven-bloom even
at periods of extremely low flow, this is not currently a realistic scenario for the Eel River. The
possibility remains that another micronutrient not studied in the modeling framework, such as
iron, could be important to this system.
matter? Do sub-grid-scale rivers have significant impacts on offshore primary productivity?
Using the Eel River in northern California, the river with the largest sediment yield per drainage
area in the continental United States, as a test case, this question is explored using two
approaches. First, a data-driven analysis of relevant time series taken on land, by buoy, and from
space, demonstrates very little evidence of direct impact of Eel River discharge on
contemporaneous coastal ocean primary productivity – but to the extent that that evidence exists,
it seems to occur during years of greatest river discharge. To further analyze mechanistic
drivers, a coupled mesoscale modeling framework unifying ocean, watershed and atmospheric
representations is formulated and run in hindcast over the 2002-2010 period. Monthly average
climatologies, interannual variabilities, and event-driven analysis of each year’s largest river
discharge are all examined for evidence of a river-ocean connection expressed through primary
production. Storm event-generated turbulence appears to dominate the primary productivity
during the winter months. The impact of the river seems to be largely independent of nutrient
load, because its dissolved nitrate is less than that of the coastal ocean. There is no evidence that
riverine delivery of gradually bioavailable detritus has a significant effect. Although a
sufficiently super-nitrous river shows the ability to sustain a plume-nutrient-driven-bloom even
at periods of extremely low flow, this is not currently a realistic scenario for the Eel River. The
possibility remains that another micronutrient not studied in the modeling framework, such as
iron, could be important to this system.
2001
Marks, Jane C.; Power, Mary E.
Nutrient induced changes in the species composition of epiphytes on Cladophora glomerata Kuetz. (Chlorophyta) Journal Article
In: Hydrobiologia, vol. 450, pp. 187-196, 2001.
Abstract | Links | BibTeX | Tags: Cladophora glomerata, epiphytes, nutrients, species composition
@article{Marks2001,
title = {Nutrient induced changes in the species composition of epiphytes on Cladophora glomerata Kuetz. (Chlorophyta)},
author = {Jane C. Marks and Mary E. Power},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Marks_2001_Hydrobiologia.pdf},
doi = {10.1023/A:1017596927664},
year = {2001},
date = {2001-00-00},
journal = {Hydrobiologia},
volume = {450},
pages = {187-196},
abstract = {Cladophora glomerata is a widely distributed filamentous freshwater alga that hosts a complex microalgal epiphyte assemblage.We manipulated nutrients and epiphyte abundances to access their effects on epiphyte biomass, epiphyte species composition, and C. glomerata growth. C. glomerata did not grow in response to these manipulations. Similarly, nutrient and epiphyte removal treatments did not alter epiphyte biovolume. Epiphyte species composition, however, changed dramatically with nutrient enrichment. The epiphyte assemblage on unenriched C. glomerata was dominated by Epithemia sorex and Epithemia adnata, whereas the assemblage on enriched C. glomerata was dominated by Achnanthidium minutissimum, Nitzschia palea and Synedra spp. These results indicate that nutrients strongly structure epiphyte species composition. Interactions between C. glomerata and its epiphytes were not affected by epiphyte species composition in our experiment but may be when C. glomerata is actively growing.},
keywords = {Cladophora glomerata, epiphytes, nutrients, species composition},
pubstate = {published},
tppubtype = {article}
}
Cladophora glomerata is a widely distributed filamentous freshwater alga that hosts a complex microalgal epiphyte assemblage.We manipulated nutrients and epiphyte abundances to access their effects on epiphyte biomass, epiphyte species composition, and C. glomerata growth. C. glomerata did not grow in response to these manipulations. Similarly, nutrient and epiphyte removal treatments did not alter epiphyte biovolume. Epiphyte species composition, however, changed dramatically with nutrient enrichment. The epiphyte assemblage on unenriched C. glomerata was dominated by Epithemia sorex and Epithemia adnata, whereas the assemblage on enriched C. glomerata was dominated by Achnanthidium minutissimum, Nitzschia palea and Synedra spp. These results indicate that nutrients strongly structure epiphyte species composition. Interactions between C. glomerata and its epiphytes were not affected by epiphyte species composition in our experiment but may be when C. glomerata is actively growing.
0000
Olhsson, Elizabeth H.
Capturing the Impact of Riverine Nutrient Delivery on Coastal Ocean Biogeochemistry PhD Thesis
U.C. Berkeley, 0000.
Abstract | Links | BibTeX | Tags: coast, nutrients, ocean biogeohemistry
@phdthesis{Olhsson2014,
title = {Capturing the Impact of Riverine Nutrient Delivery on Coastal Ocean Biogeochemistry},
author = {Elizabeth H. Olhsson},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Olhsson_2014_UCBerkTheses.pdf},
school = {U.C. Berkeley},
abstract = {Rivers smaller than the Amazon tend to be excluded from earth system modeling efforts. Does it
matter? Do sub-grid-scale rivers have significant impacts on offshore primary productivity?
Using the Eel River in northern California, the river with the largest sediment yield per drainage
area in the continental United States, as a test case, this question is explored using two
approaches. First, a data-driven analysis of relevant time series taken on land, by buoy, and from
space, demonstrates very little evidence of direct impact of Eel River discharge on
contemporaneous coastal ocean primary productivity – but to the extent that that evidence exists,
it seems to occur during years of greatest river discharge. To further analyze mechanistic
drivers, a coupled mesoscale modeling framework unifying ocean, watershed and atmospheric
representations is formulated and run in hindcast over the 2002-2010 period. Monthly average
climatologies, interannual variabilities, and event-driven analysis of each year’s largest river
discharge are all examined for evidence of a river-ocean connection expressed through primary
production. Storm event-generated turbulence appears to dominate the primary productivity
during the winter months. The impact of the river seems to be largely independent of nutrient
load, because its dissolved nitrate is less than that of the coastal ocean. There is no evidence that
riverine delivery of gradually bioavailable detritus has a significant effect. Although a
sufficiently super-nitrous river shows the ability to sustain a plume-nutrient-driven-bloom even
at periods of extremely low flow, this is not currently a realistic scenario for the Eel River. The
possibility remains that another micronutrient not studied in the modeling framework, such as
iron, could be important to this system.},
keywords = {coast, nutrients, ocean biogeohemistry},
pubstate = {published},
tppubtype = {phdthesis}
}
Rivers smaller than the Amazon tend to be excluded from earth system modeling efforts. Does it
matter? Do sub-grid-scale rivers have significant impacts on offshore primary productivity?
Using the Eel River in northern California, the river with the largest sediment yield per drainage
area in the continental United States, as a test case, this question is explored using two
approaches. First, a data-driven analysis of relevant time series taken on land, by buoy, and from
space, demonstrates very little evidence of direct impact of Eel River discharge on
contemporaneous coastal ocean primary productivity – but to the extent that that evidence exists,
it seems to occur during years of greatest river discharge. To further analyze mechanistic
drivers, a coupled mesoscale modeling framework unifying ocean, watershed and atmospheric
representations is formulated and run in hindcast over the 2002-2010 period. Monthly average
climatologies, interannual variabilities, and event-driven analysis of each year’s largest river
discharge are all examined for evidence of a river-ocean connection expressed through primary
production. Storm event-generated turbulence appears to dominate the primary productivity
during the winter months. The impact of the river seems to be largely independent of nutrient
load, because its dissolved nitrate is less than that of the coastal ocean. There is no evidence that
riverine delivery of gradually bioavailable detritus has a significant effect. Although a
sufficiently super-nitrous river shows the ability to sustain a plume-nutrient-driven-bloom even
at periods of extremely low flow, this is not currently a realistic scenario for the Eel River. The
possibility remains that another micronutrient not studied in the modeling framework, such as
iron, could be important to this system.
matter? Do sub-grid-scale rivers have significant impacts on offshore primary productivity?
Using the Eel River in northern California, the river with the largest sediment yield per drainage
area in the continental United States, as a test case, this question is explored using two
approaches. First, a data-driven analysis of relevant time series taken on land, by buoy, and from
space, demonstrates very little evidence of direct impact of Eel River discharge on
contemporaneous coastal ocean primary productivity – but to the extent that that evidence exists,
it seems to occur during years of greatest river discharge. To further analyze mechanistic
drivers, a coupled mesoscale modeling framework unifying ocean, watershed and atmospheric
representations is formulated and run in hindcast over the 2002-2010 period. Monthly average
climatologies, interannual variabilities, and event-driven analysis of each year’s largest river
discharge are all examined for evidence of a river-ocean connection expressed through primary
production. Storm event-generated turbulence appears to dominate the primary productivity
during the winter months. The impact of the river seems to be largely independent of nutrient
load, because its dissolved nitrate is less than that of the coastal ocean. There is no evidence that
riverine delivery of gradually bioavailable detritus has a significant effect. Although a
sufficiently super-nitrous river shows the ability to sustain a plume-nutrient-driven-bloom even
at periods of extremely low flow, this is not currently a realistic scenario for the Eel River. The
possibility remains that another micronutrient not studied in the modeling framework, such as
iron, could be important to this system.
Olhsson, Elizabeth H.
Capturing the Impact of Riverine Nutrient Delivery on Coastal Ocean Biogeochemistry PhD Thesis
U.C. Berkeley, 0000.
Abstract | Links | BibTeX | Tags: coast, nutrients, ocean biogeochemistry
@phdthesis{Olhsson2014bb,
title = {Capturing the Impact of Riverine Nutrient Delivery on Coastal Ocean Biogeochemistry},
author = {Elizabeth H. Olhsson},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Olhsson_2014_UCBerkTheses.pdf},
school = {U.C. Berkeley},
abstract = {Rivers smaller than the Amazon tend to be excluded from earth system modeling efforts. Does it
matter? Do sub-grid-scale rivers have significant impacts on offshore primary productivity?
Using the Eel River in northern California, the river with the largest sediment yield per drainage
area in the continental United States, as a test case, this question is explored using two
approaches. First, a data-driven analysis of relevant time series taken on land, by buoy, and from
space, demonstrates very little evidence of direct impact of Eel River discharge on
contemporaneous coastal ocean primary productivity – but to the extent that that evidence exists,
it seems to occur during years of greatest river discharge. To further analyze mechanistic
drivers, a coupled mesoscale modeling framework unifying ocean, watershed and atmospheric
representations is formulated and run in hindcast over the 2002-2010 period. Monthly average
climatologies, interannual variabilities, and event-driven analysis of each year’s largest river
discharge are all examined for evidence of a river-ocean connection expressed through primary
production. Storm event-generated turbulence appears to dominate the primary productivity
during the winter months. The impact of the river seems to be largely independent of nutrient
load, because its dissolved nitrate is less than that of the coastal ocean. There is no evidence that
riverine delivery of gradually bioavailable detritus has a significant effect. Although a
sufficiently super-nitrous river shows the ability to sustain a plume-nutrient-driven-bloom even
at periods of extremely low flow, this is not currently a realistic scenario for the Eel River. The
possibility remains that another micronutrient not studied in the modeling framework, such as
iron, could be important to this system.},
keywords = {coast, nutrients, ocean biogeochemistry},
pubstate = {published},
tppubtype = {phdthesis}
}
Rivers smaller than the Amazon tend to be excluded from earth system modeling efforts. Does it
matter? Do sub-grid-scale rivers have significant impacts on offshore primary productivity?
Using the Eel River in northern California, the river with the largest sediment yield per drainage
area in the continental United States, as a test case, this question is explored using two
approaches. First, a data-driven analysis of relevant time series taken on land, by buoy, and from
space, demonstrates very little evidence of direct impact of Eel River discharge on
contemporaneous coastal ocean primary productivity – but to the extent that that evidence exists,
it seems to occur during years of greatest river discharge. To further analyze mechanistic
drivers, a coupled mesoscale modeling framework unifying ocean, watershed and atmospheric
representations is formulated and run in hindcast over the 2002-2010 period. Monthly average
climatologies, interannual variabilities, and event-driven analysis of each year’s largest river
discharge are all examined for evidence of a river-ocean connection expressed through primary
production. Storm event-generated turbulence appears to dominate the primary productivity
during the winter months. The impact of the river seems to be largely independent of nutrient
load, because its dissolved nitrate is less than that of the coastal ocean. There is no evidence that
riverine delivery of gradually bioavailable detritus has a significant effect. Although a
sufficiently super-nitrous river shows the ability to sustain a plume-nutrient-driven-bloom even
at periods of extremely low flow, this is not currently a realistic scenario for the Eel River. The
possibility remains that another micronutrient not studied in the modeling framework, such as
iron, could be important to this system.
matter? Do sub-grid-scale rivers have significant impacts on offshore primary productivity?
Using the Eel River in northern California, the river with the largest sediment yield per drainage
area in the continental United States, as a test case, this question is explored using two
approaches. First, a data-driven analysis of relevant time series taken on land, by buoy, and from
space, demonstrates very little evidence of direct impact of Eel River discharge on
contemporaneous coastal ocean primary productivity – but to the extent that that evidence exists,
it seems to occur during years of greatest river discharge. To further analyze mechanistic
drivers, a coupled mesoscale modeling framework unifying ocean, watershed and atmospheric
representations is formulated and run in hindcast over the 2002-2010 period. Monthly average
climatologies, interannual variabilities, and event-driven analysis of each year’s largest river
discharge are all examined for evidence of a river-ocean connection expressed through primary
production. Storm event-generated turbulence appears to dominate the primary productivity
during the winter months. The impact of the river seems to be largely independent of nutrient
load, because its dissolved nitrate is less than that of the coastal ocean. There is no evidence that
riverine delivery of gradually bioavailable detritus has a significant effect. Although a
sufficiently super-nitrous river shows the ability to sustain a plume-nutrient-driven-bloom even
at periods of extremely low flow, this is not currently a realistic scenario for the Eel River. The
possibility remains that another micronutrient not studied in the modeling framework, such as
iron, could be important to this system.