Barbara Ralston is a Bureau Approving Official in the Office of Science Quality and Integrity.
Science and Products
Identifying the Vulnerability of Birds and Reptiles to Changes in Climate in the Southwest
Biodiversity is declining worldwide, and this trend could potentially become more severe as climate conditions change. An integral component of proactive adaptive management planning requires forecasts of how changes in climate will affect individual species. This need has been identified my multiple federal agencies, including the U.S. Fish and Wildlife Service, National Park Service, Bureau of L
Filter Total Items: 13
Associations between riparian plant morphological guilds and fluvial sediment dynamics along the regulated Colorado River in Grand Canyon
Effects of riparian vegetation on fluvial sediment dynamics depend on morphological traits of the constituent species. Determining the effects of different morphological guilds on sedimentation rates, as influenced by multiple aspects of dam operations, can help identify viable strategies for streamflow and vegetation management to achieve riparian resource goals. Plants of increasing size and bra
A comparison of riparian vegetation sampling methods along a large, regulated river
Monitoring riparian vegetation cover and species richness is an important component of assessing change and understanding ecosystem processes. Vegetation sampling methods determined to be the best option in other ecosystems (e.g., desert grasslands and arctic tundra) may not be the best option in multilayered, species rich, heterogeneous riparian vegetation. This study examines the strengths and w
Hydrological regime and climate interactively shape riparian vegetation composition along the Colorado River, Grand Canyon
QuestionHow closely do riparian plant communities track hydrological and climatic variation in space, and how do interactions among hydrological and climatic filters influence success of flow management strategies?LocationGrand Canyon, Arizona, USA.MethodsMulti‐year vegetation surveys were conducted across three hydrological zones – active channel, active floodplain and inactive floodplain – withi
Monitoring riparian-vegetation composition and cover along the Colorado River downstream of Glen Canyon Dam, Arizona
Vegetation in the riparian zone (the area immediately adjacent to streams, such as stream banks) along the Colorado River downstream of Glen Canyon Dam, Arizona, supports many ecosystem and societal functions. In both Glen Canyon and Grand Canyon, this ecosystem has changed over time in response to flow alterations, invasive species, and recreational use. Riparian-vegetation cover and composition
Remote sensing of tamarisk beetle (Diorhabda carinulata) impacts along 412 km of the Colorado River in the Grand Canyon, Arizona, USA
Tamarisk (Tamarix spp.) is an invasive plant species that is rapidly expanding along arid and semi-arid rivers in the western United States. A biocontrol agent, tamarisk beetle (Diorhabda carinulata), was released in 2001 in California, Colorado, Utah, and Texas. In 2009, the tamarisk beetle was found further south than anticipated in the Colorado River ecosystem within the Grand Canyon National P
Landscape-scale processes influence riparian plant composition along a regulated river
Hierarchical frameworks are useful constructs when exploring landscape- and local-scale factors affecting patterns of vegetation in riparian areas. In drylands, which have steep environmental gradients and high habitat heterogeneity, landscape-scale variables, such as climate, can change rapidly along a river's course, affecting the relative influence of environmental variables at different scales
Taxonomic and compositional differences of ground-dwelling arthropods in riparian habitats in Glen Canyon, Arizona, USA
The disturbance history, plant species composition, productivity, and structural complexity of a site can exert bottom-up controls on arthropod diversity, abundance, and trophic structure. Regulation alters the hydrology and disturbance regimes of rivers and affects riparian habitats by changing plant quality parameters. Fifty years of regulation along the Colorado River downstream of Glen Canyon
Case studies of riparian and watershed restoration in the southwestern United States—Principles, challenges, and successes
Globally, rivers and streams are highly altered by impoundments, diversions, and stream channelization associated with agricultural and water delivery needs. Climate change imposes additional challenges by further reducing discharge, introducing variability in seasonal precipitation patterns, and increasing temperatures. Collectively, these changes in a river or stream’s annual hydrology affects s
Variation in species-level plant functional traits over wetland indicator status categories
Wetland indicator status (WIS) describes the habitat affinity of plant species and is used in wetland delineations and resource inventories. Understanding how species-level functional traits vary across WIS categories may improve designations, elucidate mechanisms of adaptation, and explain habitat optima and niche. We investigated differences in species-level traits of riparian flora across WIS c
Changes in community-level riparian plant traits over inundation gradients, Colorado River, Grand Canyon
Comparisons of community-level functional traits across environmental gradients have potential for identifying links among plant characteristics, adaptations to stress and disturbance, and community assembly. We investigated community-level variation in specific leaf area (SLA), plant mature height, seed mass, stem specific gravity (SSG), relative cover of C4 species, and total plant cover over hy
Functional traits and ecological affinities of riparian plants along the Colorado River in Grand Canyon
Trait-based approaches to vegetation analyses are becoming more prevalent in studies of riparian vegetation dynamics, including responses to flow regulation, groundwater pumping, and climate change. These analyses require species trait data compiled from the literature and floras or original field measurements. Gathering such data makes trait-based research time intensive at best and impracticable
Riparian vegetation, Colorado River, and climate: five decades of spatiotemporal dynamics in the Grand Canyon with river regulation
Documentation of the interacting effects of river regulation and climate on riparian vegetation has typically been limited to small segments of rivers or focused on individual plant species. We examine spatiotemporal variability in riparian vegetation for the Colorado River in Grand Canyon relative to river regulation and climate, over the five decades since completion of the upstream Glen Canyon
Riparian vegetation data downstream of Glen Canyon Dam in Glen Canyon National Recreation Area and Grand Canyon National Park, AZ from 2014 to 2019
These data were collected by the Grand Canyon Monitoring and Research Center (GCMRC) to support riparian vegetation monitoring along the Colorado River between Glen Canyon Dam and the full pool level of Lake Mead. The objectives of the GCMRC riparian vegetation monitoring program are to annually measure and summarize the status (composition and cover) of native and non-native vascular plant specie
Southwestern Riparian Plant Trait Matrix, Colorado River, Grand Canyon, Arizona (ver. 2.0, 2022)
Trait-based approaches to vegetation analyses are becoming more prevalent in studies of riparian vegetation dynamics, including responses to flow regulation, groundwater pumping, and climate change. These analyses require species trait data compiled from the literature and floras or original field measurements. Gathering such data makes trait-based research time intensive at best and impracticable
Remote sensing derived maps of tamarisk (2009) and beetle impacts (2013) along 412 km of the Colorado River in the Grand Canyon, Arizona
These data were compiled for quantifying the area of tamarisks (Tamarix spp.) in May 2009 and to quantify the area of beetle-impacted tamarisk in May 2013 within the 2009 tamarisk classification from Glen Canyon Dam to Separation Canyon, a total distance of 412 km along the Colorado River using the 2009 and 2013 0.2 m high-resolution airborne imagery datasets. We classified tamarisk presence in 20
Ground-dwelling arthropods along the Colorado River in Arizona, USAData
These data were compiled from pitfall traps deployed at three sites, along a 25 kilometers (km) stretch of the Colorado River, immediately downstream of Glen Canyon Dam, in Glen Canyon National Recreation Area. Each site had both pre and post-dam riparian habitats present. Sampling for ground-dwelling arthropods using pitfall traps occurred continuously between June 17 and September 9, 2009. The s
Southwestern Riparian Plant Trait Matrix, Colorado River, Grand Canyon, 2014 - 2016Data
This dataset contains information on the physical traits and environmental tolerances of plant species occurring along the lower Colorado River through Grand Canyon. Due to the unique combination of plant species within the Grand Canyon, this flora shares species with many riparian areas in the western U.S.A. and represents obligate wetland to obligate upland plant species. Data for the matrix wer
Science and Products
- Science
Identifying the Vulnerability of Birds and Reptiles to Changes in Climate in the Southwest
Biodiversity is declining worldwide, and this trend could potentially become more severe as climate conditions change. An integral component of proactive adaptive management planning requires forecasts of how changes in climate will affect individual species. This need has been identified my multiple federal agencies, including the U.S. Fish and Wildlife Service, National Park Service, Bureau of L - Publications
Filter Total Items: 13
Associations between riparian plant morphological guilds and fluvial sediment dynamics along the regulated Colorado River in Grand Canyon
Effects of riparian vegetation on fluvial sediment dynamics depend on morphological traits of the constituent species. Determining the effects of different morphological guilds on sedimentation rates, as influenced by multiple aspects of dam operations, can help identify viable strategies for streamflow and vegetation management to achieve riparian resource goals. Plants of increasing size and braA comparison of riparian vegetation sampling methods along a large, regulated river
Monitoring riparian vegetation cover and species richness is an important component of assessing change and understanding ecosystem processes. Vegetation sampling methods determined to be the best option in other ecosystems (e.g., desert grasslands and arctic tundra) may not be the best option in multilayered, species rich, heterogeneous riparian vegetation. This study examines the strengths and wHydrological regime and climate interactively shape riparian vegetation composition along the Colorado River, Grand Canyon
QuestionHow closely do riparian plant communities track hydrological and climatic variation in space, and how do interactions among hydrological and climatic filters influence success of flow management strategies?LocationGrand Canyon, Arizona, USA.MethodsMulti‐year vegetation surveys were conducted across three hydrological zones – active channel, active floodplain and inactive floodplain – withiMonitoring riparian-vegetation composition and cover along the Colorado River downstream of Glen Canyon Dam, Arizona
Vegetation in the riparian zone (the area immediately adjacent to streams, such as stream banks) along the Colorado River downstream of Glen Canyon Dam, Arizona, supports many ecosystem and societal functions. In both Glen Canyon and Grand Canyon, this ecosystem has changed over time in response to flow alterations, invasive species, and recreational use. Riparian-vegetation cover and compositionRemote sensing of tamarisk beetle (Diorhabda carinulata) impacts along 412 km of the Colorado River in the Grand Canyon, Arizona, USA
Tamarisk (Tamarix spp.) is an invasive plant species that is rapidly expanding along arid and semi-arid rivers in the western United States. A biocontrol agent, tamarisk beetle (Diorhabda carinulata), was released in 2001 in California, Colorado, Utah, and Texas. In 2009, the tamarisk beetle was found further south than anticipated in the Colorado River ecosystem within the Grand Canyon National PLandscape-scale processes influence riparian plant composition along a regulated river
Hierarchical frameworks are useful constructs when exploring landscape- and local-scale factors affecting patterns of vegetation in riparian areas. In drylands, which have steep environmental gradients and high habitat heterogeneity, landscape-scale variables, such as climate, can change rapidly along a river's course, affecting the relative influence of environmental variables at different scalesTaxonomic and compositional differences of ground-dwelling arthropods in riparian habitats in Glen Canyon, Arizona, USA
The disturbance history, plant species composition, productivity, and structural complexity of a site can exert bottom-up controls on arthropod diversity, abundance, and trophic structure. Regulation alters the hydrology and disturbance regimes of rivers and affects riparian habitats by changing plant quality parameters. Fifty years of regulation along the Colorado River downstream of Glen CanyonCase studies of riparian and watershed restoration in the southwestern United States—Principles, challenges, and successes
Globally, rivers and streams are highly altered by impoundments, diversions, and stream channelization associated with agricultural and water delivery needs. Climate change imposes additional challenges by further reducing discharge, introducing variability in seasonal precipitation patterns, and increasing temperatures. Collectively, these changes in a river or stream’s annual hydrology affects sVariation in species-level plant functional traits over wetland indicator status categories
Wetland indicator status (WIS) describes the habitat affinity of plant species and is used in wetland delineations and resource inventories. Understanding how species-level functional traits vary across WIS categories may improve designations, elucidate mechanisms of adaptation, and explain habitat optima and niche. We investigated differences in species-level traits of riparian flora across WIS cChanges in community-level riparian plant traits over inundation gradients, Colorado River, Grand Canyon
Comparisons of community-level functional traits across environmental gradients have potential for identifying links among plant characteristics, adaptations to stress and disturbance, and community assembly. We investigated community-level variation in specific leaf area (SLA), plant mature height, seed mass, stem specific gravity (SSG), relative cover of C4 species, and total plant cover over hyFunctional traits and ecological affinities of riparian plants along the Colorado River in Grand Canyon
Trait-based approaches to vegetation analyses are becoming more prevalent in studies of riparian vegetation dynamics, including responses to flow regulation, groundwater pumping, and climate change. These analyses require species trait data compiled from the literature and floras or original field measurements. Gathering such data makes trait-based research time intensive at best and impracticableRiparian vegetation, Colorado River, and climate: five decades of spatiotemporal dynamics in the Grand Canyon with river regulation
Documentation of the interacting effects of river regulation and climate on riparian vegetation has typically been limited to small segments of rivers or focused on individual plant species. We examine spatiotemporal variability in riparian vegetation for the Colorado River in Grand Canyon relative to river regulation and climate, over the five decades since completion of the upstream Glen Canyon - Data
Riparian vegetation data downstream of Glen Canyon Dam in Glen Canyon National Recreation Area and Grand Canyon National Park, AZ from 2014 to 2019
These data were collected by the Grand Canyon Monitoring and Research Center (GCMRC) to support riparian vegetation monitoring along the Colorado River between Glen Canyon Dam and the full pool level of Lake Mead. The objectives of the GCMRC riparian vegetation monitoring program are to annually measure and summarize the status (composition and cover) of native and non-native vascular plant specieSouthwestern Riparian Plant Trait Matrix, Colorado River, Grand Canyon, Arizona (ver. 2.0, 2022)
Trait-based approaches to vegetation analyses are becoming more prevalent in studies of riparian vegetation dynamics, including responses to flow regulation, groundwater pumping, and climate change. These analyses require species trait data compiled from the literature and floras or original field measurements. Gathering such data makes trait-based research time intensive at best and impracticableRemote sensing derived maps of tamarisk (2009) and beetle impacts (2013) along 412 km of the Colorado River in the Grand Canyon, Arizona
These data were compiled for quantifying the area of tamarisks (Tamarix spp.) in May 2009 and to quantify the area of beetle-impacted tamarisk in May 2013 within the 2009 tamarisk classification from Glen Canyon Dam to Separation Canyon, a total distance of 412 km along the Colorado River using the 2009 and 2013 0.2 m high-resolution airborne imagery datasets. We classified tamarisk presence in 20Ground-dwelling arthropods along the Colorado River in Arizona, USAData
These data were compiled from pitfall traps deployed at three sites, along a 25 kilometers (km) stretch of the Colorado River, immediately downstream of Glen Canyon Dam, in Glen Canyon National Recreation Area. Each site had both pre and post-dam riparian habitats present. Sampling for ground-dwelling arthropods using pitfall traps occurred continuously between June 17 and September 9, 2009. The sSouthwestern Riparian Plant Trait Matrix, Colorado River, Grand Canyon, 2014 - 2016Data
This dataset contains information on the physical traits and environmental tolerances of plant species occurring along the lower Colorado River through Grand Canyon. Due to the unique combination of plant species within the Grand Canyon, this flora shares species with many riparian areas in the western U.S.A. and represents obligate wetland to obligate upland plant species. Data for the matrix wer