2021
Hood, James M.; Collis, Lyndsie M.; Schade, John D.; Stark, Rebecca A.; Finlay, Jacques C.
Longitudinal patterns and linkages in benthic fine particulate organic matter composition, respiration, and nutrient uptake Journal Article
In: Limnology and Oceanography, 2021.
Abstract | Links | BibTeX | Tags: benthic, fine particulate organic matter, microbial biomass, Nutrient Cycling, Stream Ecology
@article{Hood2021,
title = {Longitudinal patterns and linkages in benthic fine particulate organic matter composition, respiration, and nutrient uptake},
author = {James M. Hood and Lyndsie M. Collis and John D. Schade and Rebecca A. Stark and Jacques C. Finlay},
url = {https://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lno.11781},
doi = {10.1002/lno.11781},
year = {2021},
date = {2021-05-01},
journal = {Limnology and Oceanography},
abstract = {Longitudinal changes in the structure and function of river ecosystems have long been recognized, yet our understanding of how such patterns shape elemental cycles remains limited. In particular, while benthic fine particulate organic matter (POM, 0.7–1000 μm) may control many stream nutrient cycles, less is known about longitudinal patterns or controls of benthic POM‐associated nutrient uptake. We conducted a survey of benthic POM‐associated respiration and nutrient uptake as well as microbial biomass (bacteria and algae) and benthic POM composition in four size classes (0.7–53 μm, 53–106 μm, 106–250 μm, and 250–1000 μm) in six streams in the forested South Fork Eel River watershed (California), encompassing a longitudinal gradient in light availability and primary production. Benthic POM at downstream sites was composed of smaller particles with lower organic matter content that were richer in nitrogen and autotrophic material. Areal respiration and nutrient uptake rates increased 11‐ to 67‐fold with stream size. While microbial activity rates did not increase with stream size, benthic POM‐associated microbial biomass increased 20‐fold with stream size, and closely tracked a 15‐fold increase in light availability, and primary production. Thus, microbial biomass, not activity, determined longitudinal patterns in benthic POM‐associated areal nutrient uptake and respiration rates. We attribute longitudinal patterns in microbial biomass to increases in light availability and primary production. Our findings help clarify the role of local (primary production) and upstream processes in shaping ecosystem structure and function.},
keywords = {benthic, fine particulate organic matter, microbial biomass, Nutrient Cycling, Stream Ecology},
pubstate = {published},
tppubtype = {article}
}
Longitudinal changes in the structure and function of river ecosystems have long been recognized, yet our understanding of how such patterns shape elemental cycles remains limited. In particular, while benthic fine particulate organic matter (POM, 0.7–1000 μm) may control many stream nutrient cycles, less is known about longitudinal patterns or controls of benthic POM‐associated nutrient uptake. We conducted a survey of benthic POM‐associated respiration and nutrient uptake as well as microbial biomass (bacteria and algae) and benthic POM composition in four size classes (0.7–53 μm, 53–106 μm, 106–250 μm, and 250–1000 μm) in six streams in the forested South Fork Eel River watershed (California), encompassing a longitudinal gradient in light availability and primary production. Benthic POM at downstream sites was composed of smaller particles with lower organic matter content that were richer in nitrogen and autotrophic material. Areal respiration and nutrient uptake rates increased 11‐ to 67‐fold with stream size. While microbial activity rates did not increase with stream size, benthic POM‐associated microbial biomass increased 20‐fold with stream size, and closely tracked a 15‐fold increase in light availability, and primary production. Thus, microbial biomass, not activity, determined longitudinal patterns in benthic POM‐associated areal nutrient uptake and respiration rates. We attribute longitudinal patterns in microbial biomass to increases in light availability and primary production. Our findings help clarify the role of local (primary production) and upstream processes in shaping ecosystem structure and function.
2010
Hood, James Michael
Consumer nutrient stoichiometry: patterns, homeostasis, and links with fitness PhD Thesis
University of Minnesota, 2010.
Abstract | Links | BibTeX | Tags: Daphnia, Evolution and Behavior, Excretion, Nutrient Cycling, Phosphorus Stoichiometry, Stream Ecology
@phdthesis{Hood2010,
title = {Consumer nutrient stoichiometry: patterns, homeostasis, and links with fitness},
author = {James Michael Hood},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Hood_2010.pdf},
year = {2010},
date = {2010-10-01},
school = {University of Minnesota},
abstract = {The linkages between food webs and nutrient cycles are heterogeneous and
often influenced by human activities. Ecological stoichiometry provides one framework
for understanding and predicting these linkages. Yet, as it has been extended
underlying assumptions are often not evaluated. This dissertation shows that
examination of implicit and explicit assumptions reveals unknown mechanisms,
interactions, and linkages. For instance, theory assumes that invertebrate stoichiometry
does not vary with diet stoichiometry (i.e., strict homeostasis), even though many
invertebrates are not strictly homeostatic. Chapters one and two examine the role of
stoichiometric homeostasis in shaping the fitness of Daphnia'species.},
keywords = {Daphnia, Evolution and Behavior, Excretion, Nutrient Cycling, Phosphorus Stoichiometry, Stream Ecology},
pubstate = {published},
tppubtype = {phdthesis}
}
The linkages between food webs and nutrient cycles are heterogeneous and
often influenced by human activities. Ecological stoichiometry provides one framework
for understanding and predicting these linkages. Yet, as it has been extended
underlying assumptions are often not evaluated. This dissertation shows that
examination of implicit and explicit assumptions reveals unknown mechanisms,
interactions, and linkages. For instance, theory assumes that invertebrate stoichiometry
does not vary with diet stoichiometry (i.e., strict homeostasis), even though many
invertebrates are not strictly homeostatic. Chapters one and two examine the role of
stoichiometric homeostasis in shaping the fitness of Daphnia’species.
often influenced by human activities. Ecological stoichiometry provides one framework
for understanding and predicting these linkages. Yet, as it has been extended
underlying assumptions are often not evaluated. This dissertation shows that
examination of implicit and explicit assumptions reveals unknown mechanisms,
interactions, and linkages. For instance, theory assumes that invertebrate stoichiometry
does not vary with diet stoichiometry (i.e., strict homeostasis), even though many
invertebrates are not strictly homeostatic. Chapters one and two examine the role of
stoichiometric homeostasis in shaping the fitness of Daphnia’species.