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• 1. [Article] Increased Habitat Connectivity Homogenizes Freshwater Communities: Historical and Landscape Perspectives

  Increases in habitat connectivity can have consequences for taxonomic, functional, and genetic diversity of communities. Previously isolated aquatic habitats were connected with canals and pipelines in ...

  Citation × Citation Citation Abstract Copy Title: Increased Habitat Connectivity Homogenizes Freshwater Communities: Historical and Landscape Perspectives Author: Strecker, Angela L., Brittain, Jeffrey Thomas Year: 2017 Increases in habitat connectivity can have consequences for taxonomic, functional, and genetic diversity of communities. Previously isolated aquatic habitats were connected with canals and pipelines in the largest water development project in the US history, the Columbia Basin Project (CBP; eastern Washington, USA), which also altered environmental conditions; however, the ecological consequences are largely unknown. Using a historical dataset, we examined long-term patterns in zooplankton communities, water chemistry and clarity, testing the hypothesis that increased connectivity will result in taxonomic homogenization. Further, we tested contemporary drivers of communities using a comprehensive set of environmental and landscape variables. Waterbodies were sampled for zooplankton community composition as well as physical and chemical variables inside and outside the CBP using methods consistent with historical studies. We found significant declines in salinity inside the CBP, whereas changes in water clarity were prevalent across all waterbodies. Increased connectivity via canals homogenized zooplankton communities over time, as well as increasing regional richness. Other long-term changes in zooplankton communities may be related to climate change, invasive species, and land-use changes. Synthesis and applications. Though canals may offer species spatial refugia, homogenization may decrease resilience to environmental stressors. These new hybrid aquatic landscapes, or hydroscapes, should be considered carefully in future water development, including specific plans for monitoring of species and environmental conditions, as well as mitigation of undesirable conditions and/or non-native species. Title: Increased Habitat Connectivity Homogenizes Freshwater Communities: Historical and Landscape Perspectives Author: Strecker, Angela L., Brittain, Jeffrey Thomas Year: 2017 Increases in habitat connectivity can have consequences for taxonomic, functional, and genetic diversity of communities. Previously isolated aquatic habitats were connected with canals and pipelines in the largest water development project in the US history, the Columbia Basin Project (CBP; eastern Washington, USA), which also altered environmental conditions; however, the ecological consequences are largely unknown. Using a historical dataset, we examined long-term patterns in zooplankton communities, water chemistry and clarity, testing the hypothesis that increased connectivity will result in taxonomic homogenization. Further, we tested contemporary drivers of communities using a comprehensive set of environmental and landscape variables. Waterbodies were sampled for zooplankton community composition as well as physical and chemical variables inside and outside the CBP using methods consistent with historical studies. We found significant declines in salinity inside the CBP, whereas changes in water clarity were prevalent across all waterbodies. Increased connectivity via canals homogenized zooplankton communities over time, as well as increasing regional richness. Other long-term changes in zooplankton communities may be related to climate change, invasive species, and land-use changes. Synthesis and applications. Though canals may offer species spatial refugia, homogenization may decrease resilience to environmental stressors. These new hybrid aquatic landscapes, or hydroscapes, should be considered carefully in future water development, including specific plans for monitoring of species and environmental conditions, as well as mitigation of undesirable conditions and/or non-native species. Close

• 2. [Article] Foliar Nutrient Concentrations Related to Soil Sources Across a Range of Sites in the Northeastern United States

  Understanding the supply of nutrients from various soil sources and the sensitivity of tree species to soil nutrient availability is critical for predicting the effects of declines in base cations due ...

  Citation × Citation Citation Abstract Copy Title: Foliar Nutrient Concentrations Related to Soil Sources Across a Range of Sites in the Northeastern United States Author: Lucash, Melissa S., Yanai, Ruth D., Blum, Joel D., Park, B. B. Year: 2011 Understanding the supply of nutrients from various soil sources and the sensitivity of tree species to soil nutrient availability is critical for predicting the effects of declines in base cations due to acid rain and forest harvesting on forest health and productivity. We collected soil samples from 19 sites in the northeastern United States, chemically analyzed them using a sequential extraction procedure, and compared them to the chemical composition of foliage of the dominant tree species. Concentrations of Ca and Mg in foliage were correlated with exchangeable Ca and Mg concentrations in the upper mineral soil; for most tree species they were also correlated to acid-extractable Ca and Mg in the parent material (C horizon). Foliar P was better correlated with soil P in the upper mineral soil than in the C horizon, while foliar AI was insensitive to soil AI concentrations. In five sites in New Hampshire, the Ca/Sr of foliage was consistent with that of the Oie horizon, after taking the reported discrimination of Ca over Sr into account. In sites in New York, without an Oie horizon, the Ca/Sr of foliage was too high to be explained by any of the soil pools. A comparison of Ca/Sr ratios of foliage among species at common sites showed oak (Quercus spp.) to have higher Ca/Sr ratios than sugar maple (Acer saccharum Marsh.), birch (Betula spp.), red maple (A. rubrum L.) and beech (Fagus spp.). The interpretation of soil Ca sources from Ca/Sr ratios is complicated at sites where a single horizon does not dominate the source. Title: Foliar Nutrient Concentrations Related to Soil Sources Across a Range of Sites in the Northeastern United States Author: Lucash, Melissa S., Yanai, Ruth D., Blum, Joel D., Park, B. B. Year: 2011 Understanding the supply of nutrients from various soil sources and the sensitivity of tree species to soil nutrient availability is critical for predicting the effects of declines in base cations due to acid rain and forest harvesting on forest health and productivity. We collected soil samples from 19 sites in the northeastern United States, chemically analyzed them using a sequential extraction procedure, and compared them to the chemical composition of foliage of the dominant tree species. Concentrations of Ca and Mg in foliage were correlated with exchangeable Ca and Mg concentrations in the upper mineral soil; for most tree species they were also correlated to acid-extractable Ca and Mg in the parent material (C horizon). Foliar P was better correlated with soil P in the upper mineral soil than in the C horizon, while foliar AI was insensitive to soil AI concentrations. In five sites in New Hampshire, the Ca/Sr of foliage was consistent with that of the Oie horizon, after taking the reported discrimination of Ca over Sr into account. In sites in New York, without an Oie horizon, the Ca/Sr of foliage was too high to be explained by any of the soil pools. A comparison of Ca/Sr ratios of foliage among species at common sites showed oak (Quercus spp.) to have higher Ca/Sr ratios than sugar maple (Acer saccharum Marsh.), birch (Betula spp.), red maple (A. rubrum L.) and beech (Fagus spp.). The interpretation of soil Ca sources from Ca/Sr ratios is complicated at sites where a single horizon does not dominate the source. Close

• 3. [Article] Spatial and Temporal Patterns of Amphibian Chytrid Fungus <i>Batrachochytrium Dendrobatidis</i> Occupancy in Amphibian Habitats

  Chytrid fungi are the most ancestral of the fungi and are global in distribution. There are over 1200 species of Chytridiomycota described from freshwater, marine and terrestrial systems in temperate, ...

  Citation × Citation Citation Abstract Copy Title: Spatial and Temporal Patterns of Amphibian Chytrid Fungus <i>Batrachochytrium Dendrobatidis</i> Occupancy in Amphibian Habitats Author: Chestnut, Tara Year: 2013 Chytrid fungi are the most ancestral of the fungi and are global in distribution. There are over 1200 species of Chytridiomycota described from freshwater, marine and terrestrial systems in temperate, tropical and tundra environments. Chytridiales are characterized by a range of morphologies and share the flask- or pot-like shape of the zoosporangia, within which motile zoospores develop. Chytrids function primarily as plant saprobes and parasites, but some also parasitize animals. Chytrids are observed in conjunction with the decline of freshwater and marine algal blooms, they decompose excess pollen, and comprise the fungal flora in gut of herbivores. Some chytrids also parasitize micro-invertebrates, insects and amphibians. The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd) is the only chytrid known to infect a vertebrate host. Bd exists free-living in the aquatic environment. Lab experiments have demonstrated Bd survival on sterilized moist sand for up to three months and it remained infective in lake water for up to seven weeks. Bd cultures can be maintained under lab conditions for several months (personal observation), which suggests Bd can survive in the environment without a host as long as nutrients are not limiting. In the aquatic environment, Bd is detected by filtering water samples to capture free-living zoospores and zoosporangia then performing a qPCR analysis. Bd has not been reliably isolated from sediments. The goal of our research was to study free-living Bd in amphibian habitats to better understand its ecology and host-pathogen dynamics. Title: Spatial and Temporal Patterns of Amphibian Chytrid Fungus <i>Batrachochytrium Dendrobatidis</i> Occupancy in Amphibian Habitats Author: Chestnut, Tara Year: 2013 Chytrid fungi are the most ancestral of the fungi and are global in distribution. There are over 1200 species of Chytridiomycota described from freshwater, marine and terrestrial systems in temperate, tropical and tundra environments. Chytridiales are characterized by a range of morphologies and share the flask- or pot-like shape of the zoosporangia, within which motile zoospores develop. Chytrids function primarily as plant saprobes and parasites, but some also parasitize animals. Chytrids are observed in conjunction with the decline of freshwater and marine algal blooms, they decompose excess pollen, and comprise the fungal flora in gut of herbivores. Some chytrids also parasitize micro-invertebrates, insects and amphibians. The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd) is the only chytrid known to infect a vertebrate host. Bd exists free-living in the aquatic environment. Lab experiments have demonstrated Bd survival on sterilized moist sand for up to three months and it remained infective in lake water for up to seven weeks. Bd cultures can be maintained under lab conditions for several months (personal observation), which suggests Bd can survive in the environment without a host as long as nutrients are not limiting. In the aquatic environment, Bd is detected by filtering water samples to capture free-living zoospores and zoosporangia then performing a qPCR analysis. Bd has not been reliably isolated from sediments. The goal of our research was to study free-living Bd in amphibian habitats to better understand its ecology and host-pathogen dynamics. Close

• 4. [Article] Climate Change and Land Management Impact Rangeland Condition and Sage-Grouse Habitat in Southeastern Oregon

  Contemporary pressures on sagebrush steppe from climate change, exotic species, wildfire, and land use change threaten rangeland species such as the greater sage-grouse (Centrocercus urophasianus). To ...

  Citation × Citation Citation Abstract Copy Title: Climate Change and Land Management Impact Rangeland Condition and Sage-Grouse Habitat in Southeastern Oregon Author: Creutzburg, Megan K., Henderson, Emilie B., Conklin, David R. Year: 2015 Contemporary pressures on sagebrush steppe from climate change, exotic species, wildfire, and land use change threaten rangeland species such as the greater sage-grouse (Centrocercus urophasianus). To effectively manage sagebrush steppe landscapes for long-term goals, managers need information about the potential impacts of climate change, disturbances, and management activities. We integrated information from a dynamic global vegetation model, a sage-grouse habitat climate envelope model, and a state-and-transition simulation model to project broad-scale vegetation dynamics and potential sage-grouse habitat across 23.5 million acres in southeastern Oregon. We evaluated four climate scenarios, including continuing current climate and three scenarios of global climate change, and three management scenarios, including no management, current management and a sage-grouse habitat restoration scenario. All climate change scenarios projected expansion of moist shrub steppe and contraction of dry shrub steppe, but climate scenarios varied widely in the projected extent of xeric shrub steppe, where hot, dry summer conditions are unfavorable for sage-grouse. Wildfire increased by 26% over the century under current climate due to exotic grass encroachment, and by two- to four-fold across all climate change scenarios as extreme fire years became more frequent. Exotic grasses rapidly expanded in all scenarios as large areas of the landscape initially in semi-degraded condition converted to exotic-dominated systems. Due to the combination of exotic grass invasion, juniper encroachment, and climatic unsuitability for sage-grouse, projected sage-grouse habitat declined in the first several decades, but increased in area under the three climate change scenarios later in the century, as moist shrub steppe increased and rangeland condition improved. Management activities in the model were generally unsuccessful in controlling exotic grass invasion but were effective in slowing woodland expansion. Current levels of restoration treatments were insufficient to prevent some juniper expansion, but increased treatment rates under the restoration scenario maintained juniper near initial levels in priority treatment areas. Our simulations indicate that climate change may have both positive and negative implications for maintaining sage-grouse habitat. Title: Climate Change and Land Management Impact Rangeland Condition and Sage-Grouse Habitat in Southeastern Oregon Author: Creutzburg, Megan K., Henderson, Emilie B., Conklin, David R. Year: 2015 Contemporary pressures on sagebrush steppe from climate change, exotic species, wildfire, and land use change threaten rangeland species such as the greater sage-grouse (Centrocercus urophasianus). To effectively manage sagebrush steppe landscapes for long-term goals, managers need information about the potential impacts of climate change, disturbances, and management activities. We integrated information from a dynamic global vegetation model, a sage-grouse habitat climate envelope model, and a state-and-transition simulation model to project broad-scale vegetation dynamics and potential sage-grouse habitat across 23.5 million acres in southeastern Oregon. We evaluated four climate scenarios, including continuing current climate and three scenarios of global climate change, and three management scenarios, including no management, current management and a sage-grouse habitat restoration scenario. All climate change scenarios projected expansion of moist shrub steppe and contraction of dry shrub steppe, but climate scenarios varied widely in the projected extent of xeric shrub steppe, where hot, dry summer conditions are unfavorable for sage-grouse. Wildfire increased by 26% over the century under current climate due to exotic grass encroachment, and by two- to four-fold across all climate change scenarios as extreme fire years became more frequent. Exotic grasses rapidly expanded in all scenarios as large areas of the landscape initially in semi-degraded condition converted to exotic-dominated systems. Due to the combination of exotic grass invasion, juniper encroachment, and climatic unsuitability for sage-grouse, projected sage-grouse habitat declined in the first several decades, but increased in area under the three climate change scenarios later in the century, as moist shrub steppe increased and rangeland condition improved. Management activities in the model were generally unsuccessful in controlling exotic grass invasion but were effective in slowing woodland expansion. Current levels of restoration treatments were insufficient to prevent some juniper expansion, but increased treatment rates under the restoration scenario maintained juniper near initial levels in priority treatment areas. Our simulations indicate that climate change may have both positive and negative implications for maintaining sage-grouse habitat. Close

• 5. [Article] Report on Wintering Western Snowy Plovers at Coos Bay North Spit and Impacts to Plovers from The North Jetty Repair Project, Winter 2009

  The Western Snowy Plover (Charadrius alexandrinus nivosus) breeds along the coast of the Pacific Ocean in California, Oregon, and Washington and at alkaline lakes in the interior of the western United ...

  Citation × Citation Citation Abstract Copy Title: Report on Wintering Western Snowy Plovers at Coos Bay North Spit and Impacts to Plovers from The North Jetty Repair Project, Winter 2009 Author: Lauten, David J., Castelein, Kathleen J., Gaines, Eleanor P. Year: 2009 The Western Snowy Plover (Charadrius alexandrinus nivosus) breeds along the coast of the Pacific Ocean in California, Oregon, and Washington and at alkaline lakes in the interior of the western United States (Page et al. 1991). Loss of habitat, predation pressures, and disturbance have caused the decline of the coastal population of Snowy Plovers and led to the listing of the Pacific Coast Population of Western Snowy Plovers as Threatened on March 5, 1993 (U.S. Fish and Wildlife Service 1993). Oregon Western Snowy Plovers are known to winter along the coast of Oregon as well as migrate to other wintering locations, mainly in California (Lauten et al. 2001, ORNHIC unpublished data). Previous winter surveys along the Oregon coast (Oregon Department of Fish and Wildlife, unpublished data, ORNHIC unpublished data) have documented the locations of wintering Snowy Plovers. Coos Bay North Spit (CBNS) is one location where plovers are known to winter. During the winter of 2008-2009, Army Corp of Engineers (ACOE) contracted Kerr Contractors, Inc. to complete repairs on the North Jetty of the Coos River. ACOE consulted with U.S. Fish and Wildlife Service (USFWS) regarding impacts to sensitive species including Western Snowy Plover. ACOE contracted Oregon Natural Heritage Information Center (ORNHIC) to complete two Snowy Plover surveys prior to jetty repair work, two plover surveys per week during repair work, and two plover surveys post repair work to document any potential impacts to wintering plovers. In winter, plovers tend to spend much of their time roosting along the high tide wrack line, but also spend time foraging, often on the wet sand near the surf (ORHIC, unpublished data). At CBNS, winter Snowy Plover survey data has shown that plovers will roost and feed on the beach north of the North Jetty, but also spend time roosting on the South Spoil and Habitat Restoration Areas (HRAs) east of the foredune. Large 20-ton dump trucks and other large equipment were used to haul material to the North Jetty. Vehicles used the foredune road that bisects the HRAs. Our objectives were to survey and monitor Snowy Plovers on the beach, HRAs, and South Spoil, to document the number of plovers using the area and any impacts or disturbance to the plovers during the North Jetty repair project. Title: Report on Wintering Western Snowy Plovers at Coos Bay North Spit and Impacts to Plovers from The North Jetty Repair Project, Winter 2009 Author: Lauten, David J., Castelein, Kathleen J., Gaines, Eleanor P. Year: 2009 The Western Snowy Plover (Charadrius alexandrinus nivosus) breeds along the coast of the Pacific Ocean in California, Oregon, and Washington and at alkaline lakes in the interior of the western United States (Page et al. 1991). Loss of habitat, predation pressures, and disturbance have caused the decline of the coastal population of Snowy Plovers and led to the listing of the Pacific Coast Population of Western Snowy Plovers as Threatened on March 5, 1993 (U.S. Fish and Wildlife Service 1993). Oregon Western Snowy Plovers are known to winter along the coast of Oregon as well as migrate to other wintering locations, mainly in California (Lauten et al. 2001, ORNHIC unpublished data). Previous winter surveys along the Oregon coast (Oregon Department of Fish and Wildlife, unpublished data, ORNHIC unpublished data) have documented the locations of wintering Snowy Plovers. Coos Bay North Spit (CBNS) is one location where plovers are known to winter. During the winter of 2008-2009, Army Corp of Engineers (ACOE) contracted Kerr Contractors, Inc. to complete repairs on the North Jetty of the Coos River. ACOE consulted with U.S. Fish and Wildlife Service (USFWS) regarding impacts to sensitive species including Western Snowy Plover. ACOE contracted Oregon Natural Heritage Information Center (ORNHIC) to complete two Snowy Plover surveys prior to jetty repair work, two plover surveys per week during repair work, and two plover surveys post repair work to document any potential impacts to wintering plovers. In winter, plovers tend to spend much of their time roosting along the high tide wrack line, but also spend time foraging, often on the wet sand near the surf (ORHIC, unpublished data). At CBNS, winter Snowy Plover survey data has shown that plovers will roost and feed on the beach north of the North Jetty, but also spend time roosting on the South Spoil and Habitat Restoration Areas (HRAs) east of the foredune. Large 20-ton dump trucks and other large equipment were used to haul material to the North Jetty. Vehicles used the foredune road that bisects the HRAs. Our objectives were to survey and monitor Snowy Plovers on the beach, HRAs, and South Spoil, to document the number of plovers using the area and any impacts or disturbance to the plovers during the North Jetty repair project. Close