2016
Uno, Hiromi
Spatial and temporal linkage of stream-riparian food webs by seasonal migration of mayfly Ephemerella maculata PhD Thesis
University of California, Berkeley, 2016, ISBN: 978-1-369-05549-8.
Abstract | BibTeX | Tags: Aquatic insect, Aquatic-terrestrial linkage, Biological sciences, ERCZO, food web, Spatial heterogeneity, subsidy, Temporal heterogeneity
@phdthesis{Uno2016,
title = {Spatial and temporal linkage of stream-riparian food webs by seasonal migration of mayfly Ephemerella maculata},
author = {Hiromi Uno},
isbn = {978-1-369-05549-8},
year = {2016},
date = {2016-05-30},
school = {University of California, Berkeley},
abstract = {Stream environments are spatially and temporally heterogeneous. Mainstem rivers are often wide,
sunlit, warm and productive, while tributaries are shaded by riparian trees, unproductive, and
remain cool in summer. Within mainstem rivers themselves there is substantial spatial
heterogeneity in habitat structure and physical conditions, such as water temperature. River
environments also change dramatically with season. Organisms that live in the riverine
environment respond to and take advantage of such heterogeneous environments by moving
between microhabitats or shifting their phenology. I studied the life cycle of a riverine mayfly,
Ephemerella maculata (Ephemerellidae), in a northern California river system, its responses to
spatial and temporal heterogeneity, and how its movements connect stream and riparian food webs
in space and time.
I discovered that E. maculata migrates between the mainstem and tributaries of rivers during its
life cycle, thereby linking food webs in these two habitats, and enhancing predator growth in
unproductive tributaries. The resource subsidy from productive but warm rivers to cool,
unproductive tributaries associated with the mayfly migration increase the growth of stenothermic
predators like juvenile salmonids in otherwise food-limited, cool thermal refuges, and increase
their resilience to future warming. Furthermore, I examined the resilience of E. maculata to
changes in water temperature using field surveys and lab rearing experiments. I discovered that
different life stages of E. maculata have different thermal responses, and they shift their phenology
depending on the water temperature, allowing each life stage to occur in the most desirable thermal
condition. Therefore, as long as the natural seasonal pattern of the water temperature is sustained,
E. maculata can resist temperature changes by shifting their phenology. Finally, I have shown that
thermal spatial heterogeneity of rivers desynchronizes mayfly emergence timing, prolonging the
subsidy period to riparian predators, and changing the predators’ responses to this subsidy.},
keywords = {Aquatic insect, Aquatic-terrestrial linkage, Biological sciences, ERCZO, food web, Spatial heterogeneity, subsidy, Temporal heterogeneity},
pubstate = {published},
tppubtype = {phdthesis}
}
Stream environments are spatially and temporally heterogeneous. Mainstem rivers are often wide,
sunlit, warm and productive, while tributaries are shaded by riparian trees, unproductive, and
remain cool in summer. Within mainstem rivers themselves there is substantial spatial
heterogeneity in habitat structure and physical conditions, such as water temperature. River
environments also change dramatically with season. Organisms that live in the riverine
environment respond to and take advantage of such heterogeneous environments by moving
between microhabitats or shifting their phenology. I studied the life cycle of a riverine mayfly,
Ephemerella maculata (Ephemerellidae), in a northern California river system, its responses to
spatial and temporal heterogeneity, and how its movements connect stream and riparian food webs
in space and time.
I discovered that E. maculata migrates between the mainstem and tributaries of rivers during its
life cycle, thereby linking food webs in these two habitats, and enhancing predator growth in
unproductive tributaries. The resource subsidy from productive but warm rivers to cool,
unproductive tributaries associated with the mayfly migration increase the growth of stenothermic
predators like juvenile salmonids in otherwise food-limited, cool thermal refuges, and increase
their resilience to future warming. Furthermore, I examined the resilience of E. maculata to
changes in water temperature using field surveys and lab rearing experiments. I discovered that
different life stages of E. maculata have different thermal responses, and they shift their phenology
depending on the water temperature, allowing each life stage to occur in the most desirable thermal
condition. Therefore, as long as the natural seasonal pattern of the water temperature is sustained,
E. maculata can resist temperature changes by shifting their phenology. Finally, I have shown that
thermal spatial heterogeneity of rivers desynchronizes mayfly emergence timing, prolonging the
subsidy period to riparian predators, and changing the predators’ responses to this subsidy.
sunlit, warm and productive, while tributaries are shaded by riparian trees, unproductive, and
remain cool in summer. Within mainstem rivers themselves there is substantial spatial
heterogeneity in habitat structure and physical conditions, such as water temperature. River
environments also change dramatically with season. Organisms that live in the riverine
environment respond to and take advantage of such heterogeneous environments by moving
between microhabitats or shifting their phenology. I studied the life cycle of a riverine mayfly,
Ephemerella maculata (Ephemerellidae), in a northern California river system, its responses to
spatial and temporal heterogeneity, and how its movements connect stream and riparian food webs
in space and time.
I discovered that E. maculata migrates between the mainstem and tributaries of rivers during its
life cycle, thereby linking food webs in these two habitats, and enhancing predator growth in
unproductive tributaries. The resource subsidy from productive but warm rivers to cool,
unproductive tributaries associated with the mayfly migration increase the growth of stenothermic
predators like juvenile salmonids in otherwise food-limited, cool thermal refuges, and increase
their resilience to future warming. Furthermore, I examined the resilience of E. maculata to
changes in water temperature using field surveys and lab rearing experiments. I discovered that
different life stages of E. maculata have different thermal responses, and they shift their phenology
depending on the water temperature, allowing each life stage to occur in the most desirable thermal
condition. Therefore, as long as the natural seasonal pattern of the water temperature is sustained,
E. maculata can resist temperature changes by shifting their phenology. Finally, I have shown that
thermal spatial heterogeneity of rivers desynchronizes mayfly emergence timing, prolonging the
subsidy period to riparian predators, and changing the predators’ responses to this subsidy.