Mary Freeman, Ph.D. (Former Employee)
Science and Products
Filter Total Items: 110
The missing dead: The lost role of animal remains in nutrient cycling in North American Rivers 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...
Authors
Seth J. Wenger, Amanda L. Subalusky, Mary Freeman
Stream fish colonization but not persistence varies regionally across a large North American river basin 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...
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 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...
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 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...
Authors
Kit Wheeler, Seth J. Wenger, Mary Freeman
Local adaptation in Trinidadian guppies alters stream ecosystem structure at landscape scales despite high environmental variability 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...
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 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...
Authors
James Wood, Mary Freeman
Science and Products
Filter Total Items: 110
The missing dead: The lost role of animal remains in nutrient cycling in North American Rivers 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...
Authors
Seth J. Wenger, Amanda L. Subalusky, Mary Freeman
Stream fish colonization but not persistence varies regionally across a large North American river basin 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...
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 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...
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 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...
Authors
Kit Wheeler, Seth J. Wenger, Mary Freeman
Local adaptation in Trinidadian guppies alters stream ecosystem structure at landscape scales despite high environmental variability 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...
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 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...
Authors
James Wood, Mary Freeman