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 Data for the matrix were compiled from published scientific papers, unpublished reports, plant fact sheets, existing trait databases, regional floras, and plant guides. Categorical, ordinal, and continuous data are included in this dataset. This dataset does not contain sensitive or classified data.

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 in some cases. To support trait-based analysis of vegetation along the Colorado River through Grand Canyon, a data set of 20 biological traits and ecological affinities for 179 species occurring in that study area was compiled. This diverse flora shares species with many riparian areas in the western USA and includes species that occur across a wide moisture gradient. 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 Data were compiled from published scientific papers, unpublished reports, plant fact sheets, existing trait databases, regional floras, and plant guides. Data for ordinal environmental tolerances were more readily available than were quantitative traits. Categorical, ordinal, and continuous data are included in this dataset. Also, this dataset includes data from McCoy-Sulentic et al. 2017, who measured or compiled data on specific leaf area (SLA), stem specific gravity (SSG), seed mass, and mature height of 110 plant species that occur along the Colorado River in Grand Canyon, Arizona. Additionally, they measured leaf δ13C, δ15N, % carbon, % nitrogen, and C/N ratio of 56 species with C3 photosynthesis. This dataset does not contain sensitive or classified data.

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 in some cases. To support trait-based analysis of vegetation along the Colorado River through Grand Canyon, a data set of 20 biological traits and ecological affinities for 179 species occurring in that study area was compiled. This diverse flora shares species with many riparian areas in the western USA and includes species that occur across a wide moisture gradient. 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 were compiled from published scientific papers, unpublished reports, plant fact sheets, existing trait databases, regional floras, and plant guides. Data for ordinal environmental tolerances were more readily available than were quantitative traits. Categorical, ordinal, and continuous data are included in this dataset. Also, this dataset includes data from McCoy-Sulentic et al. 2017, who measured or compiled data on specific leaf area (SLA), stem specific gravity (SSG), seed mass, and mature height of 110 plant species that occur along the Colorado River in Grand Canyon, Arizona. Additionally, they measured leaf δ13C, δ15N, % carbon, % nitrogen, and C/N ratio of 56 species with C3 photosynthesis. This dataset does not contain sensitive or classified data.

These data were compiled or measured (depending on the trait) for 110 plant species which were documented in vegetation monitoring surveys in years 2012-2014 along the Colorado River through Grand Canyon National Park. New trait data was collected forspecific leaf area, stem specific gravity, δ13C, δ15N, percent carbon and nitrogen, and carbon/nitrogen ratio. Seed mass and plant height data were collected from the literature and the KEW Royal Botanic Garden Seed Information Database (http://data.kew.org/sid/).

These data were compiled or measured (depending on the trait) for 110 plant species which were documented in vegetation monitoring surveys in years 2012-2014 along the Colorado River through Grand Canyon National Park. New trait data was collected forspecific leaf area, stem specific gravity, δ13C, δ15N, percent carbon and nitrogen, and carbon/nitrogen ratio. Seed mass and plant height data were collected from the literature and the KEW Royal Botanic Garden Seed Information Database (http://data.kew.org/sid/).

These data were compiled based on field observations and available literature. Field observations of plant cover were made in September and October of 2013 and 2014, while trait measurements were made in September and October of 2014 and 2015. Field data was collected on sandbars along the Colorado River through Grand Canyon between river miles 0 and 226. Field measurements of specific leaf area, stem specific gravity, and total cover. Plant height was taken from the Flora of North America, the Jepson Desert Manual, or A Utah Flora. Seed mass values were available from the Kew Seed Information Database (http://data.kew.org/sid/). Photosynthetic pathway was compiled from published literature. The trait values were converted to a community-level value using two matrices: a matrix of the relative species cover (species cover/total cover) and a matrix of the average trait value for each species. These two matrices were multiplied, and then summed over all species in each plot to produce a community-level trait value for each plot. Inundation was calculated as the yearly average of the number of hours for each plot that the river stage, based on stage-discharge relationships, was greater than the surveyed plot elevation using USGS streamflow data. This exceedance probability was calculated as the probability that stage height will exceed plot height for the 2013 survey plots based on the 1984 - 2013 USGS streamflow record.

These data were compiled based on field observations and available literature. Field observations of plant cover were made in September and October of 2013 and 2014, while trait measurements were made in September and October of 2014 and 2015. Field data was collected on sandbars along the Colorado River through Grand Canyon between river miles 0 and 226. Field measurements of specific leaf area, stem specific gravity, and total cover. Plant height was taken from the Flora of North America, the Jepson Desert Manual, or A Utah Flora. Seed mass values were available from the Kew Seed Information Database (http://data.kew.org/sid/). Photosynthetic pathway was compiled from published literature. The trait values were converted to a community-level value using two matrices: a matrix of the relative species cover (species cover/total cover) and a matrix of the average trait value for each species. These two matrices were multiplied, and then summed over all species in each plot to produce a community-level trait value for each plot. Inundation was calculated as the yearly average of the number of hours for each plot that the river stage, based on stage-discharge relationships, was greater than the surveyed plot elevation using USGS streamflow data. This exceedance probability was calculated as the probability that stage height will exceed plot height for the 2013 survey plots based on the 1984 - 2013 USGS streamflow record.

These data consist of species relative cover, percent cover of dead plant material, percent cover of soil and rock, and a variety of broad - and local- scale environmental variables. These data relate to sample sites along the Colorado River through Grand Canyon between Lees Ferry and river mile 245. The plant and ground cover data included here were originally collected as a part of annual vegetation monitoring by Grand Canyon Monitoring and Research Center. Environmental variables were either recorded in the field or obtained through other data sources. Species and ground cover data were collected in August and September 2014 at 96 randomly selected sample sites that were approximately evenly distributed along the river corridor. The sample sites were distributed among three geomorphic features: channel margins (44), debris fans (28), and sandbars (24).

These data consist of species relative cover, percent cover of dead plant material, percent cover of soil and rock, and a variety of broad - and local- scale environmental variables. These data relate to sample sites along the Colorado River through Grand Canyon between Lees Ferry and river mile 245. The plant and ground cover data included here were originally collected as a part of annual vegetation monitoring by Grand Canyon Monitoring and Research Center. Environmental variables were either recorded in the field or obtained through other data sources. Species and ground cover data were collected in August and September 2014 at 96 randomly selected sample sites that were approximately evenly distributed along the river corridor. The sample sites were distributed among three geomorphic features: channel margins (44), debris fans (28), and sandbars (24).

These data were compiled to assess the status and trends of riparian plant communities along the Colorado River between Glen Canyon Dam and Lake Mead, AZ. Three metrics have been proposed to evaluate the "Riparian Vegetation" goal identified in the Glen Canyon Dam Adaptive Management Program's Long Term Experimental and Management Plan (U.S. Department of Interior, 2016). The three metrics are total living plant cover, the proportion of living cover composed of native species, and native species richness. Current policies for Glen Canyon Dam operations result in three longitudinal bands within the riparian area that are flooded at different frequencies. The band, or hydrologic zone, that is most frequently inundated is referred to here as the “active channel” or “AC.” This includes all areas inundated by releases up to 25,000 cubic feet per second (707 m3/s). The “active floodplain” or “AF” is inundated by high flow experiments and includes areas that are inundated by releases between 25,000 cubic feet per second and 45,000 cubic feet per second (1,274 m3/s). The “inactive floodplain” or “IF” is the area along the river that is inundated by releases over 45,000 cubic feet per second, which is not planned under current policies. The metrics are assessed for each of these hydrologic zones. Data from the Grand Canyon Monitoring and Research Center's riparian vegetation monitoring protocol (Palmquist and others, 2018) can be used to evaluate these metrics, which is what is provided here. In short, 80-100 sample sites are randomly selected each year. These sites include debris fans, eddy sandbars, and channel margins. At each randomly selected sample site, ocular cover estimates of each plant species occurring in 1-m2 quadrats spanning the hydrological zones are recorded, along with an estimate of total living plant cover and associated environmental variables. The first metric, total living plant cover, consists of two pieces of data; plant occurrence (a plant is present in the sample frame) and plant cover (proportion of the sample frame covered with living plants). Cover is represented by both an ordinal cover class (1, 2, 3, 4, 5, 6, etc.) and the midpoint of the cover class value (0.01%, 0.5%, 1%, 5%, 10%, 15%, etc). The proportion of native cover is the sum total of native plant cover divided by the sum total of plant cover (native plus nonnative cover) for a sample frame. Native plant richness is the total number of native species rooted inside a sample frame. The total living plant cover data are available for 2016 through 2023. The native cover and richness data are available for 2014 and 2016 through 2023.