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• 1. [Article] Distribution and Behavior Study of Diurnal Tree Squirrels in Portland, Oregon, with Emphasis on the Western Gray Squirrel (Saiurus grieeus griseus Ord) and the Western Fox Squirrel (S. niger rufiventer E. Geoffroy St.-Hilaire)

  Populations of diurnal tree squirrels in the Portland area were located by mail surveys, personal interviews, and field inspections. Pine squirrels were found to reside in thickly wooded residential areas ...

  Citation × Citation Citation Abstract Copy Title: Distribution and Behavior Study of Diurnal Tree Squirrels in Portland, Oregon, with Emphasis on the Western Gray Squirrel (Saiurus grieeus griseus Ord) and the Western Fox Squirrel (S. niger rufiventer E. Geoffroy St.-Hilaire) Author: Rice, Ira Young Year: 1977 Populations of diurnal tree squirrels in the Portland area were located by mail surveys, personal interviews, and field inspections. Pine squirrels were found to reside in thickly wooded residential areas with dense understories and running water nearby. Western gray squirrels occupied habitats in relatively quiet residential neighborhoods, in areas well supplied with mast crops. Western fox squirrels were found to coexist with gray squirrels in their preferred habitat, and also to thrive in park settings with few mast trees and high activity and noise levels. In areas occupied by both fox and gray squirrels, dominant-subordinate relationships were noted. Each species tolerated the others. Title: Distribution and Behavior Study of Diurnal Tree Squirrels in Portland, Oregon, with Emphasis on the Western Gray Squirrel (Saiurus grieeus griseus Ord) and the Western Fox Squirrel (S. niger rufiventer E. Geoffroy St.-Hilaire) Author: Rice, Ira Young Year: 1977 Populations of diurnal tree squirrels in the Portland area were located by mail surveys, personal interviews, and field inspections. Pine squirrels were found to reside in thickly wooded residential areas with dense understories and running water nearby. Western gray squirrels occupied habitats in relatively quiet residential neighborhoods, in areas well supplied with mast crops. Western fox squirrels were found to coexist with gray squirrels in their preferred habitat, and also to thrive in park settings with few mast trees and high activity and noise levels. In areas occupied by both fox and gray squirrels, dominant-subordinate relationships were noted. Each species tolerated the others. Close

• 2. [Article] Distribution Drivers and Physiological Responses in Geothermal Bryophyte Communities

  Premise of Study: Our ability to explain community structure rests on our ability to define the importance of ecological niches, including realized ecological niches, in shaping communities, but few studies ...

  Citation × Citation Citation Abstract Copy Title: Distribution Drivers and Physiological Responses in Geothermal Bryophyte Communities Author: García, Estefanía Llaneza, Rosenstiel, Todd N., Graves, Camille Brianne, Shortlidge, Erin E., Eppley, Sarah M. Year: 2016 Premise of Study: Our ability to explain community structure rests on our ability to define the importance of ecological niches, including realized ecological niches, in shaping communities, but few studies of plant distributions have combined predictive models with physiological measures. Methods: Using field surveys and statistical modeling, we predicted distribution drivers in geothermal bryophyte (moss) communities of Lassen Volcanic National Park (California, USA). In the laboratory, we used drying and rewetting experiments to test whether the strong species-specific effects of relative humidity on distributions predicted by the models were correlated with physiological characters. Key Results: We found that the three most common bryophytes in geothermal communities were significantly affected by three distinct distribution drivers: temperature, light, and relative humidity. Aulacomnium palustre, whose distribution is significantly affected by relative humidity according to our model, and which occurs in high-humidity sites, showed extreme signs of stress after drying and never recovered optimal values of PSII efficiency after rewetting. Campylopus introflexus, whose distribution is not affected by humidity according to our model, was able to maintain optimal values of PSII efficiency for 48 hr at 50% water loss and recovered optimal values of PSII efficiency after rewetting. Conclusions: Our results suggest that species-specific environmental stressors tightly constrain the ecological niches of geothermal bryophytes. Tests of tolerance to drying in two bryophyte species corresponded with model predictions of the comparative importance of relative humidity as distribution drivers for these species. Title: Distribution Drivers and Physiological Responses in Geothermal Bryophyte Communities Author: García, Estefanía Llaneza, Rosenstiel, Todd N., Graves, Camille Brianne, Shortlidge, Erin E., Eppley, Sarah M. Year: 2016 Premise of Study: Our ability to explain community structure rests on our ability to define the importance of ecological niches, including realized ecological niches, in shaping communities, but few studies of plant distributions have combined predictive models with physiological measures. Methods: Using field surveys and statistical modeling, we predicted distribution drivers in geothermal bryophyte (moss) communities of Lassen Volcanic National Park (California, USA). In the laboratory, we used drying and rewetting experiments to test whether the strong species-specific effects of relative humidity on distributions predicted by the models were correlated with physiological characters. Key Results: We found that the three most common bryophytes in geothermal communities were significantly affected by three distinct distribution drivers: temperature, light, and relative humidity. Aulacomnium palustre, whose distribution is significantly affected by relative humidity according to our model, and which occurs in high-humidity sites, showed extreme signs of stress after drying and never recovered optimal values of PSII efficiency after rewetting. Campylopus introflexus, whose distribution is not affected by humidity according to our model, was able to maintain optimal values of PSII efficiency for 48 hr at 50% water loss and recovered optimal values of PSII efficiency after rewetting. Conclusions: Our results suggest that species-specific environmental stressors tightly constrain the ecological niches of geothermal bryophytes. Tests of tolerance to drying in two bryophyte species corresponded with model predictions of the comparative importance of relative humidity as distribution drivers for these species. Close

• 3. [Article] Phenotypic Variation in the Model Organism, Danio Rerio

  Model organisms are used to study evolutionary conserved traits. Zebrafish (Danio rerio) are used a model organism because of their highly fecundity, external fertilization, and robust nature, making them ...

  Citation × Citation Citation Abstract Copy Title: Phenotypic Variation in the Model Organism, Danio Rerio Author: Champaigne, Rachel D, Brown, Kim H. Year: 2014 Model organisms are used to study evolutionary conserved traits. Zebrafish (Danio rerio) are used a model organism because of their highly fecundity, external fertilization, and robust nature, making them highly adaptable to environmental and genetic variation. In an effort to limit data variation that lies outside of topic interest, phenotypic measures of variation must be performed, understood, and taken into consideration for future studies. A common measurement of phenotypic variation in fish is in the maximum (Ucrit) swimming speeds. Inter and intra-strain variation in zebrafish Ucrit swimming speeds will be observed in a swim tunnel. Baseline values will be recorded from ten fish from each of two families in each of three strains: WIK, Tubigan and AB. Environmental variation in zebrafish raised (beginning at one month of age) in tanks with various volumes and densities of fish will also be recorded from each strain. Mitochondrial density in white muscle will be compared in each strain in each condition. Diet, take salinity, pH, temperature, and light exposure will all remain constant for all fish. Title: Phenotypic Variation in the Model Organism, Danio Rerio Author: Champaigne, Rachel D, Brown, Kim H. Year: 2014 Model organisms are used to study evolutionary conserved traits. Zebrafish (Danio rerio) are used a model organism because of their highly fecundity, external fertilization, and robust nature, making them highly adaptable to environmental and genetic variation. In an effort to limit data variation that lies outside of topic interest, phenotypic measures of variation must be performed, understood, and taken into consideration for future studies. A common measurement of phenotypic variation in fish is in the maximum (Ucrit) swimming speeds. Inter and intra-strain variation in zebrafish Ucrit swimming speeds will be observed in a swim tunnel. Baseline values will be recorded from ten fish from each of two families in each of three strains: WIK, Tubigan and AB. Environmental variation in zebrafish raised (beginning at one month of age) in tanks with various volumes and densities of fish will also be recorded from each strain. Mitochondrial density in white muscle will be compared in each strain in each condition. Diet, take salinity, pH, temperature, and light exposure will all remain constant for all fish. Close

• 4. [Article] Influence of light on algal growth in the lower Willamette River

  During the summer of 1974 chemical conditions in the lower reaches of the Willamette River, Oregon were similar to those in other rivers currently experiencing nuisance algal growth problems. Temperature ...

  Citation × Citation Citation Abstract Copy Title: Influence of light on algal growth in the lower Willamette River Author: Wille, Stephen Arthur Year: 1976 During the summer of 1974 chemical conditions in the lower reaches of the Willamette River, Oregon were similar to those in other rivers currently experiencing nuisance algal growth problems. Temperature and chemical nutrients are not limiting. Relatively high populations of phytoplankton and productivity values for upstream periphyton beds and surface waters suggest moderately eutrophic conditions. However, with increased depth in the lower river, and a constant euphotic zone, the amount of photosynthetically available light is reduced. With sufficient depth and complete mixing the critical depth is exceeded. Primary productivity rates are subsequently limited by low light availability in the lower river. Title: Influence of light on algal growth in the lower Willamette River Author: Wille, Stephen Arthur Year: 1976 During the summer of 1974 chemical conditions in the lower reaches of the Willamette River, Oregon were similar to those in other rivers currently experiencing nuisance algal growth problems. Temperature and chemical nutrients are not limiting. Relatively high populations of phytoplankton and productivity values for upstream periphyton beds and surface waters suggest moderately eutrophic conditions. However, with increased depth in the lower river, and a constant euphotic zone, the amount of photosynthetically available light is reduced. With sufficient depth and complete mixing the critical depth is exceeded. Primary productivity rates are subsequently limited by low light availability in the lower river. Close

• 5. [Article] Rare, Threatened and Endangered Species of Oregon

  Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within ...

  Citation × Citation Citation Abstract Copy Title: Rare, Threatened and Endangered Species of Oregon Author: Kagan, James S., Vrilakas, Sue, Gaines, Eleanor P., Alton, Cliff, McArthur, Fern, Walsh, Kuuipo, Scheuering, Eric, Christy, John A., Hak, Jon, Tobalske, Claudine, Weiland, Annie, Koloszar, Theresa, Oregon Natural Heritage Information Center Year: 2004 Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within the next 100 years. The major cause of this phenomenon is large-scale destruction of native habitats, which has increased since European settlement began in the mid 1800's - in Oregon and throughout the New World. Once lost, a species can never be recovered, and there is no way of knowing how useful it may have been. We do know that human beings and many of their industries depend on plant and animal products. About 50% of all pharmaceuticals have a natural component as an active ingredient, yet less than one percent of the world's species have been chemically analyzed and tested. Many invertebrates and plants contain undescribed and highly functional compounds. Limnanthes floccosa subsp. grandiflora, or wooly meadow-foam, a rare plant that grows in southwest Oregon, has been recently found to produce a hybrid with the more common member of the genus, Limnanthes alba. This hybrid grows well in the poorly drained soils of the Willamette Valley and produces a valuable oil used for soaps, plastic and rubber production. In addition, the new hybrid meadow-foam does not require the field burning necessary for other crops. This species, and many other Oregon natives, will be lost without intervention. The purpose of this publication is to provide land managers, owners and interested parties with a list of those species in Oregon which are in greatest jeopardy. Title: Rare, Threatened and Endangered Species of Oregon Author: Kagan, James S., Vrilakas, Sue, Gaines, Eleanor P., Alton, Cliff, McArthur, Fern, Walsh, Kuuipo, Scheuering, Eric, Christy, John A., Hak, Jon, Tobalske, Claudine, Weiland, Annie, Koloszar, Theresa, Oregon Natural Heritage Information Center Year: 2004 Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within the next 100 years. The major cause of this phenomenon is large-scale destruction of native habitats, which has increased since European settlement began in the mid 1800's - in Oregon and throughout the New World. Once lost, a species can never be recovered, and there is no way of knowing how useful it may have been. We do know that human beings and many of their industries depend on plant and animal products. About 50% of all pharmaceuticals have a natural component as an active ingredient, yet less than one percent of the world's species have been chemically analyzed and tested. Many invertebrates and plants contain undescribed and highly functional compounds. Limnanthes floccosa subsp. grandiflora, or wooly meadow-foam, a rare plant that grows in southwest Oregon, has been recently found to produce a hybrid with the more common member of the genus, Limnanthes alba. This hybrid grows well in the poorly drained soils of the Willamette Valley and produces a valuable oil used for soaps, plastic and rubber production. In addition, the new hybrid meadow-foam does not require the field burning necessary for other crops. This species, and many other Oregon natives, will be lost without intervention. The purpose of this publication is to provide land managers, owners and interested parties with a list of those species in Oregon which are in greatest jeopardy. Close

• 6. [Article] Rare, Threatened and Endangered Species of Oregon

  Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within ...

  Citation × Citation Citation Abstract Copy Title: Rare, Threatened and Endangered Species of Oregon Author: Kagan, James S., Vrilakas, Sue, Gaines, Eleanor P., Alton, Cliff, Koepke, Lindsey, Christy, John A., Doyle, Erin Year: 2010 Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within the next 100 years. The major cause of this phenomenon is human caused changes to the environment, which continue to increase - in Oregon and throughout the world. Once lost, a species can never be recovered, and there is no way of knowing how useful it may have been. We do know that human beings and many of their industries depend on plant and animal products. About 50% of all pharmaceuticals have a natural component as an active ingredient, yet less than one percent of the world's species have been chemically analyzed and tested. Many invertebrates and plants contain undescribed and highly functional compounds. Limnanthes floccosa subsp. grandiflora, or wooly meadow-foam, a rare plant that grows in southwest Oregon, has been recently found to produce a hybrid with the more common member of the genus, Limnanthes alba. This hybrid grows well in the poorly drained soils of the Willamette Valley and produces a valuable oil used for soaps, plastic and rubber production. In addition, the new hybrid meadow-foam does not require the field burning necessary for other crops. This species, and many other Oregon natives, will be lost without intervention. The purpose of this publication is to provide land managers, owners and interested parties with a list of those species in Oregon which are in greatest jeopardy. Title: Rare, Threatened and Endangered Species of Oregon Author: Kagan, James S., Vrilakas, Sue, Gaines, Eleanor P., Alton, Cliff, Koepke, Lindsey, Christy, John A., Doyle, Erin Year: 2010 Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within the next 100 years. The major cause of this phenomenon is human caused changes to the environment, which continue to increase - in Oregon and throughout the world. Once lost, a species can never be recovered, and there is no way of knowing how useful it may have been. We do know that human beings and many of their industries depend on plant and animal products. About 50% of all pharmaceuticals have a natural component as an active ingredient, yet less than one percent of the world's species have been chemically analyzed and tested. Many invertebrates and plants contain undescribed and highly functional compounds. Limnanthes floccosa subsp. grandiflora, or wooly meadow-foam, a rare plant that grows in southwest Oregon, has been recently found to produce a hybrid with the more common member of the genus, Limnanthes alba. This hybrid grows well in the poorly drained soils of the Willamette Valley and produces a valuable oil used for soaps, plastic and rubber production. In addition, the new hybrid meadow-foam does not require the field burning necessary for other crops. This species, and many other Oregon natives, will be lost without intervention. The purpose of this publication is to provide land managers, owners and interested parties with a list of those species in Oregon which are in greatest jeopardy. Close

• 7. [Article] Rare, Threatened and Endangered Plants and Animals of Oregon

  Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within ...

  Citation × Citation Citation Abstract Copy Title: Rare, Threatened and Endangered Plants and Animals of Oregon Author: Kagan, James S., Vrilakas, Sue, Gaines, Eleanor P., Alton, Cliff, Popper, Ken, Stern, Mark A., Scheuering, Eric, Christy, John A., Finnerty, Mary, Hak, Jon, Tovar, Anthony A., Murray, Michael, Tobalske, Claudine, Oregon Natural Heritage Program Year: 2001 Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within the next 100 years. The major cause of this phenomenon is large-scale destruction of native habitats, which has increased since European settlement began in the mid 1800's - in Oregon and throughout the New World. Once lost, a species can never be recovered, and there is no way of knowing how useful it may have been. We do know that human beings and many of their industries depend on plant and animal products. About 50% of all pharmaceuticals have a natural component as an active ingredient, yet less than one percent of the world's species have been chemically analyzed and tested. Many invertebrates and plants contain undescribed and highly functional compounds. Limnanthes floccosa subsp. grandiflora, or wooly meadow-foam, a rare plant that grows in southwest Oregon, has been recently found to produce a hybrid with the more common member of the genus, Limnanthes alba. This hybrid grows well in the poorly drained soils of the Willamette Valley and produces a valuable oil used for soaps, plastic and rubber production. In addition, the new hybrid meadow-foam does not require the field burning necessary for other crops. This species, and many other Oregon natives, will be lost without intervention. The purpose of this book is to provide land managers, owners and interested parties with a list of those species in Oregon which are in greatest jeopardy. Title: Rare, Threatened and Endangered Plants and Animals of Oregon Author: Kagan, James S., Vrilakas, Sue, Gaines, Eleanor P., Alton, Cliff, Popper, Ken, Stern, Mark A., Scheuering, Eric, Christy, John A., Finnerty, Mary, Hak, Jon, Tovar, Anthony A., Murray, Michael, Tobalske, Claudine, Oregon Natural Heritage Program Year: 2001 Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within the next 100 years. The major cause of this phenomenon is large-scale destruction of native habitats, which has increased since European settlement began in the mid 1800's - in Oregon and throughout the New World. Once lost, a species can never be recovered, and there is no way of knowing how useful it may have been. We do know that human beings and many of their industries depend on plant and animal products. About 50% of all pharmaceuticals have a natural component as an active ingredient, yet less than one percent of the world's species have been chemically analyzed and tested. Many invertebrates and plants contain undescribed and highly functional compounds. Limnanthes floccosa subsp. grandiflora, or wooly meadow-foam, a rare plant that grows in southwest Oregon, has been recently found to produce a hybrid with the more common member of the genus, Limnanthes alba. This hybrid grows well in the poorly drained soils of the Willamette Valley and produces a valuable oil used for soaps, plastic and rubber production. In addition, the new hybrid meadow-foam does not require the field burning necessary for other crops. This species, and many other Oregon natives, will be lost without intervention. The purpose of this book is to provide land managers, owners and interested parties with a list of those species in Oregon which are in greatest jeopardy. Close

• 8. [Article] Rare, Threatened and Endangered Species of Oregon

  Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within ...

  Citation × Citation Citation Abstract Copy Title: Rare, Threatened and Endangered Species of Oregon Author: Kagan, James S., Vrilakas, Sue, Christy, John A., Gaines, Eleanor P., Wise, Lindsey, Pahl, Cameron, Howell, Kathy Year: 2016 Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within the next 100 years. The major reasons for this are human caused changes to the environment, which continue to increase - in Oregon and throughout the world. Once lost, a species can never be recovered, and there is no way of knowing how useful it may have been. We do know that human beings and many of their industries depend on plant and animal products. About 50% of all pharmaceuticals have a natural component as an active ingredient, yet less than one percent of the world's species have been chemically analyzed and tested. Many insects and plants contain undescribed and highly functional compounds. Limnanthes pumila subsp. grandiflora, or wooly meadow-foam, a rare plant that grows in southwest Oregon, has been found to produce a hybrid with the more common member of the genus, Limnanthes alba. This hybrid grows well in the poorly drained soils of the Willamette Valley and produces a valuable oil used for soaps, plastic and rubber production. In addition, the new hybrid meadow-foam does not require the field burning necessary for other crops. This species, and many other Oregon natives, will be lost without intervention. The purpose of this publication is to provide land managers, owners and interested parties with a list of those species in Oregon which are in greatest jeopardy. Title: Rare, Threatened and Endangered Species of Oregon Author: Kagan, James S., Vrilakas, Sue, Christy, John A., Gaines, Eleanor P., Wise, Lindsey, Pahl, Cameron, Howell, Kathy Year: 2016 Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within the next 100 years. The major reasons for this are human caused changes to the environment, which continue to increase - in Oregon and throughout the world. Once lost, a species can never be recovered, and there is no way of knowing how useful it may have been. We do know that human beings and many of their industries depend on plant and animal products. About 50% of all pharmaceuticals have a natural component as an active ingredient, yet less than one percent of the world's species have been chemically analyzed and tested. Many insects and plants contain undescribed and highly functional compounds. Limnanthes pumila subsp. grandiflora, or wooly meadow-foam, a rare plant that grows in southwest Oregon, has been found to produce a hybrid with the more common member of the genus, Limnanthes alba. This hybrid grows well in the poorly drained soils of the Willamette Valley and produces a valuable oil used for soaps, plastic and rubber production. In addition, the new hybrid meadow-foam does not require the field burning necessary for other crops. This species, and many other Oregon natives, will be lost without intervention. The purpose of this publication is to provide land managers, owners and interested parties with a list of those species in Oregon which are in greatest jeopardy. Close

• 9. [Article] Sex-Specific Morphological and Physiological Differences in the Moss Ceratodon purpureus (Dicranales)

  Background and Aims: Dioecy and sexual dimorphism occur in many terrestrial plant species but are especially widespread among the bryophytes. Despite the prevalence of dioecy in non-vascular plants, surprisingly ...

  Citation × Citation Citation Abstract Copy Title: Sex-Specific Morphological and Physiological Differences in the Moss Ceratodon purpureus (Dicranales) Author: Slate, Mandy L., Rosenstiel, Todd N., Eppley, Sarah M. Year: 2017 Background and Aims: Dioecy and sexual dimorphism occur in many terrestrial plant species but are especially widespread among the bryophytes. Despite the prevalence of dioecy in non-vascular plants, surprisingly little is known about how fine-scale sex-specific cell and leaf morphological traits are correlated with sex-specific physiology and population sex ratios. Such data are critical to understanding the inter-relationship between sex-specific morphological and physiological characters and how their relationship influences population structure. In this study, these data types were assessed to determine how they vary across three populations within one moss species and whether fine-scale morphological traits scale up to physiological and sex ratio characteristics. Methods: Twenty cell-, leaf- and canopy-level traits and two photochemical measurements were compared between sexes and populations of the dioecious moss Ceratodon purpureus. Field population-expressed sex ratios were obtained for the same populations. Key Results: Male and female plants differed in cell, leaf and photochemical measures. These sexual dimorphisms were female biased, with females having larger and thicker leaves and greater values for chlorophyll fluorescence-based, leaf photochemistry measurements than males. Female traits were also more variable than male traits. Interestingly, field population sex ratios were significantly male biased in two study populations and female biased in the third study population. Conclusions: The results demonstrate that the larger morphology and the greater physiological output of female C. purpureus gametophytes compared with males occurs across populations and is likely to have significant effects on resource allocation and biotic interactions. However, this high level of dimorphism does not explain population sex ratio variation in the three study populations tested. This research lays the groundwork for future studies on how differential sex-specific variation in cell and leaf traits influences bryophyte plant fitness. Title: Sex-Specific Morphological and Physiological Differences in the Moss Ceratodon purpureus (Dicranales) Author: Slate, Mandy L., Rosenstiel, Todd N., Eppley, Sarah M. Year: 2017 Background and Aims: Dioecy and sexual dimorphism occur in many terrestrial plant species but are especially widespread among the bryophytes. Despite the prevalence of dioecy in non-vascular plants, surprisingly little is known about how fine-scale sex-specific cell and leaf morphological traits are correlated with sex-specific physiology and population sex ratios. Such data are critical to understanding the inter-relationship between sex-specific morphological and physiological characters and how their relationship influences population structure. In this study, these data types were assessed to determine how they vary across three populations within one moss species and whether fine-scale morphological traits scale up to physiological and sex ratio characteristics. Methods: Twenty cell-, leaf- and canopy-level traits and two photochemical measurements were compared between sexes and populations of the dioecious moss Ceratodon purpureus. Field population-expressed sex ratios were obtained for the same populations. Key Results: Male and female plants differed in cell, leaf and photochemical measures. These sexual dimorphisms were female biased, with females having larger and thicker leaves and greater values for chlorophyll fluorescence-based, leaf photochemistry measurements than males. Female traits were also more variable than male traits. Interestingly, field population sex ratios were significantly male biased in two study populations and female biased in the third study population. Conclusions: The results demonstrate that the larger morphology and the greater physiological output of female C. purpureus gametophytes compared with males occurs across populations and is likely to have significant effects on resource allocation and biotic interactions. However, this high level of dimorphism does not explain population sex ratio variation in the three study populations tested. This research lays the groundwork for future studies on how differential sex-specific variation in cell and leaf traits influences bryophyte plant fitness. Close