Mary Freeman, Ph.D.
Mary Freeman is a research ecologist with the Eastern Ecological Science Center at Athens, GA.
She received a B.S. in biology (1979), a M.S. in entomology (1982) and a Ph.D. in forest resources (1990) from the University of Georgia. Before joining Patuxent, Mary conducted research for the U.S. Fish and Wildlife Service and the National Biological Service in Auburn, AL (1992-1996). Mary serves as affiliate faculty at the Odum School of Ecology, University of Georgia, and on the graduate faculties at the University of Georgia and Auburn University.
Science and Products
Filter Total Items: 108
Identifying life history traits that promote occurrence for four minnow (Leuciscidae) species in intermittent Gulf Coastal Plain streams
- Life history traits of stream fishes partly reflect adaptations to disturbance regimes, which in turn shape assemblage composition via environmental filters. In this study, we focused on life history traits of four morphologically similar leuciscid species in coastal plain streams of southwestern GA that are shifting from historically perennial to intermittent flow. We evaluated differences in r
Authors
Jessica L. Davis, Mary Freeman, Stephen W. Golladay
Water velocity regulates macro-consumer herbivory on the benthic macrophyte Podostemum ceratophyllum Michx.
1) Macrophytes influence aquatic ecosystems by increasing habitat complexity and providing trophic resources for aquatic fauna. While herbivory on freshwater macrophytes is widely documented in lakes, low-velocity riverine habitats, the influence of herbivory on macrophytes in higher-velocity habitats has rarely been examined.
2) We investigated the hypothesis that high water velocity can reduc
Authors
James L Wood, Jon W Skaggs, Caitlin C Conn, Mary Freeman
Long-term (37 years) impacts of low-head dams on freshwater shrimp habitat connectivity in northeastern Puerto Rico
Freshwater migratory shrimp in Puerto Rico depend on watershed connectivity, from stream headwaters to the ocean, to complete their life cycle. Moreover, shrimp populations in different watersheds are known to be connected in an island-wide metapopulation. However, low-head dams paired with water intakes on streams draining the El Yunque National Forest (EYNF) reduce streamflow. Here, we examine t
Authors
Jessica Chappell, S. Kyle McKay, Mary Freeman, Catherine M. Pringle
Adaptive management of flows from R.L. Harris Dam (Tallapoosa River, Alabama)—Stakeholder process and use of biological monitoring data for decision making
Adaptive management has been applied to problems with multiple conflicting objectives in various natural resources settings to learn how management actions affect divergent values regarding system response. Hydropower applications have only recently begun to emerge in the field, yet in the specific example reported herein, stakeholders invested in determining the best management alternatives for a
Authors
Elise R. Irwin, Mary Freeman, James Peterson, Kathryn D.M. Kennedy, M. Clint Lloyd, Kristie M. Ouellette Coffman, Ely Kosnicki, Tom Hess
Annual survival, site fidelity, and longevity in the eastern coastal population of the Painted Bunting (Passerina ciris) based on a 20-year mark-recapture/resighting study
A long-term study of annual survival, longevity, and site fidelity in the eastern coastal population of the Painted Bunting (Passerina ciris) during the breeding season was conducted from 1999 through 2018 in the outer coastal plain of the southeastern Atlantic coast of the United States. Painted Buntings were uniquely color-banded from 1999 through 2003 at 40 study sites that were paired at 20 lo
Authors
Paul W. Jr Sykes, Mary Freeman, Joan J. Sykes, John T. Seginak, M. David Oleyar, Joshua P. Egan
The missing dead: The lost role of animal remains in nutrient cycling in North American Rivers
While leaf litter, wood, and other plant remnants are known to play a central role in lotic ecosystems, animal remains (carcasses, bones, shells) have received less attention. We propose a simple classification scheme for animal remains in rivers based on origin (authochthonous vs. allochthonous) and frequency (pulsed vs continuous). We then present case studies in which we estimate the former bio
Authors
Seth J. Wenger, Amanda L. Subalusky, Mary Freeman
Stream fish colonization but not persistence varies regionally across a large North American river basin
Many species have distributions that span distinctly different physiographic regions, and effective conservation of such taxa will require a full accounting of all factors that potentially influence populations. Ecologists recognize effects of physiographic differences in topography, geology and climate on local habitat configurations, and thus the relevance of landscape heterogeneity to species d
Authors
Kit Wheeler, Seth J. Wenger, Stephen J. Walsh, Zachary P. Martin, Howard L. Jelks, Mary Freeman
Long-term monitoring data provide evidence of declining species richness in a river valued for biodiversity conservation
Free-flowing river segments provide refuges for many imperiled aquatic biota that have been extirpated elsewhere in their native ranges. These biodiversity refuges are also foci of conservation concerns because species persisting within isolated habitat fragments may be particularly vulnerable to local environmental change. We have analyzed long-term (14- and 20-y) survey data to assess evidence o
Authors
Mary Freeman, Megan M. Hagler, Phillip M. Bumpers, Kit Wheeler, Seth J. Wenger, Byron J. Freeman
States and rates: Complementary approaches to developing flow‐ecology relationships
In recognition of the influence of flow on riverine habitats and organisms, stream ecologists have devoted considerable effort to the development of quantitative predictive relationships describing ecological responses to flow variability, i.e. flow‐ecology relationships.Methods used to generate flow‐ecology relationships can be thought of as a continuum bookended by pure states approaches on one
Authors
Kit Wheeler, Seth J. Wenger, Mary Freeman
Local adaptation in Trinidadian guppies alters stream ecosystem structure at landscape scales despite high environmental variability
While previous studies have shown that evolutionary divergence alters ecological processes in small-scale experiments, a major challenge is to assess whether such evolutionary effects are important in natural ecosystems at larger spatial scales. At the landscape scale, across eight streams in the Caroni drainage, we found that the presence of locally adapted populations of guppies (Poecilia reticu
Authors
Troy N. Simon, Ronald D. Bassar, Andrew J. Binderup, Alex S. Flecker, Mary Freeman, James F. Gill, Michael C. Marshall, Steve A. Thomas, Joseph Travis, David N. Reznick, Catherine M. Pringle
Ecology of the macrophyte Podostemum ceratophyllum Michx. (Hornleaf riverweed), a widespread foundation species of eastern North American rivers
Podostemum ceratophyllum, commonly called Hornleaf Riverweed, occurs in mid-order montane and piedmont rivers of eastern North America, where the plant grows submerged and attached to rocks and stable substrates in swift, aerated water. Multiple studies, mostly conducted in the southern portions of the plant’s range, have shown that Podostemum can variously influence benthic communities in flowing
Authors
James Wood, Mary Freeman
Organic-matter retention and macroinvertebrate utilization of seasonally inundated bryophytes in a mid-order Piedmont River
There is increased understanding of the role of bryophytes in supporting invertebrate biomass and for their influence on nutrient cycling and carbon balance in aquatic systems, but the structural and functional role of bryophytes growing in seasonally inundated habitats is substantially less studied. We conducted a study on the Middle Oconee River, near Athens, GA, to assess invertebrate abundance
Authors
James Wood, Meryom Pattillo, Mary Freeman
Science and Products
Filter Total Items: 108
Identifying life history traits that promote occurrence for four minnow (Leuciscidae) species in intermittent Gulf Coastal Plain streams
- Life history traits of stream fishes partly reflect adaptations to disturbance regimes, which in turn shape assemblage composition via environmental filters. In this study, we focused on life history traits of four morphologically similar leuciscid species in coastal plain streams of southwestern GA that are shifting from historically perennial to intermittent flow. We evaluated differences in r
Authors
Jessica L. Davis, Mary Freeman, Stephen W. Golladay
Water velocity regulates macro-consumer herbivory on the benthic macrophyte Podostemum ceratophyllum Michx.
1) Macrophytes influence aquatic ecosystems by increasing habitat complexity and providing trophic resources for aquatic fauna. While herbivory on freshwater macrophytes is widely documented in lakes, low-velocity riverine habitats, the influence of herbivory on macrophytes in higher-velocity habitats has rarely been examined.
2) We investigated the hypothesis that high water velocity can reduc
Authors
James L Wood, Jon W Skaggs, Caitlin C Conn, Mary Freeman
Long-term (37 years) impacts of low-head dams on freshwater shrimp habitat connectivity in northeastern Puerto Rico
Freshwater migratory shrimp in Puerto Rico depend on watershed connectivity, from stream headwaters to the ocean, to complete their life cycle. Moreover, shrimp populations in different watersheds are known to be connected in an island-wide metapopulation. However, low-head dams paired with water intakes on streams draining the El Yunque National Forest (EYNF) reduce streamflow. Here, we examine t
Authors
Jessica Chappell, S. Kyle McKay, Mary Freeman, Catherine M. Pringle
Adaptive management of flows from R.L. Harris Dam (Tallapoosa River, Alabama)—Stakeholder process and use of biological monitoring data for decision making
Adaptive management has been applied to problems with multiple conflicting objectives in various natural resources settings to learn how management actions affect divergent values regarding system response. Hydropower applications have only recently begun to emerge in the field, yet in the specific example reported herein, stakeholders invested in determining the best management alternatives for a
Authors
Elise R. Irwin, Mary Freeman, James Peterson, Kathryn D.M. Kennedy, M. Clint Lloyd, Kristie M. Ouellette Coffman, Ely Kosnicki, Tom Hess
Annual survival, site fidelity, and longevity in the eastern coastal population of the Painted Bunting (Passerina ciris) based on a 20-year mark-recapture/resighting study
A long-term study of annual survival, longevity, and site fidelity in the eastern coastal population of the Painted Bunting (Passerina ciris) during the breeding season was conducted from 1999 through 2018 in the outer coastal plain of the southeastern Atlantic coast of the United States. Painted Buntings were uniquely color-banded from 1999 through 2003 at 40 study sites that were paired at 20 lo
Authors
Paul W. Jr Sykes, Mary Freeman, Joan J. Sykes, John T. Seginak, M. David Oleyar, Joshua P. Egan
The missing dead: The lost role of animal remains in nutrient cycling in North American Rivers
While leaf litter, wood, and other plant remnants are known to play a central role in lotic ecosystems, animal remains (carcasses, bones, shells) have received less attention. We propose a simple classification scheme for animal remains in rivers based on origin (authochthonous vs. allochthonous) and frequency (pulsed vs continuous). We then present case studies in which we estimate the former bio
Authors
Seth J. Wenger, Amanda L. Subalusky, Mary Freeman
Stream fish colonization but not persistence varies regionally across a large North American river basin
Many species have distributions that span distinctly different physiographic regions, and effective conservation of such taxa will require a full accounting of all factors that potentially influence populations. Ecologists recognize effects of physiographic differences in topography, geology and climate on local habitat configurations, and thus the relevance of landscape heterogeneity to species d
Authors
Kit Wheeler, Seth J. Wenger, Stephen J. Walsh, Zachary P. Martin, Howard L. Jelks, Mary Freeman
Long-term monitoring data provide evidence of declining species richness in a river valued for biodiversity conservation
Free-flowing river segments provide refuges for many imperiled aquatic biota that have been extirpated elsewhere in their native ranges. These biodiversity refuges are also foci of conservation concerns because species persisting within isolated habitat fragments may be particularly vulnerable to local environmental change. We have analyzed long-term (14- and 20-y) survey data to assess evidence o
Authors
Mary Freeman, Megan M. Hagler, Phillip M. Bumpers, Kit Wheeler, Seth J. Wenger, Byron J. Freeman
States and rates: Complementary approaches to developing flow‐ecology relationships
In recognition of the influence of flow on riverine habitats and organisms, stream ecologists have devoted considerable effort to the development of quantitative predictive relationships describing ecological responses to flow variability, i.e. flow‐ecology relationships.Methods used to generate flow‐ecology relationships can be thought of as a continuum bookended by pure states approaches on one
Authors
Kit Wheeler, Seth J. Wenger, Mary Freeman
Local adaptation in Trinidadian guppies alters stream ecosystem structure at landscape scales despite high environmental variability
While previous studies have shown that evolutionary divergence alters ecological processes in small-scale experiments, a major challenge is to assess whether such evolutionary effects are important in natural ecosystems at larger spatial scales. At the landscape scale, across eight streams in the Caroni drainage, we found that the presence of locally adapted populations of guppies (Poecilia reticu
Authors
Troy N. Simon, Ronald D. Bassar, Andrew J. Binderup, Alex S. Flecker, Mary Freeman, James F. Gill, Michael C. Marshall, Steve A. Thomas, Joseph Travis, David N. Reznick, Catherine M. Pringle
Ecology of the macrophyte Podostemum ceratophyllum Michx. (Hornleaf riverweed), a widespread foundation species of eastern North American rivers
Podostemum ceratophyllum, commonly called Hornleaf Riverweed, occurs in mid-order montane and piedmont rivers of eastern North America, where the plant grows submerged and attached to rocks and stable substrates in swift, aerated water. Multiple studies, mostly conducted in the southern portions of the plant’s range, have shown that Podostemum can variously influence benthic communities in flowing
Authors
James Wood, Mary Freeman
Organic-matter retention and macroinvertebrate utilization of seasonally inundated bryophytes in a mid-order Piedmont River
There is increased understanding of the role of bryophytes in supporting invertebrate biomass and for their influence on nutrient cycling and carbon balance in aquatic systems, but the structural and functional role of bryophytes growing in seasonally inundated habitats is substantially less studied. We conducted a study on the Middle Oconee River, near Athens, GA, to assess invertebrate abundance
Authors
James Wood, Meryom Pattillo, Mary Freeman