The Southwest Exotic Plant Mapping Program (SWEMP) is a collaborative effort between the United States Geological Survey and federal, tribal, state, county and non-governmental organization (NGO) partners in the southwest. This project is an ongoing effort to compile and distribute regional data on the occurrence of non-native invasive plants in the southwestern United States. The database represents the known sites (represented by a point location, i.e. site) of non-native invasive plant infestations within Arizona and New Mexico, and adjacent portions of California, Colorado, Nevada and Utah. These data, collected from 1911 to 2006, represent the field observations of various state, federal, tribal and county agencies, along with some specimen data from Herbaria. The SWEMP database comprises a compilation of data submitted through 2006.

Exotic plant patches detected on monitoring routes at Curecanti NRA, June 21-27, 2023

Exotic plant patches detected on monitoring routes at Curecanti NRA, June 21-27, 2023

Tabular data set summarizing detection and location of invasive plants on islands in Alaska Maritime National Wildlife Refuge between July 14, 2024 and July 31, 2024. Data has been reformatted from its original format to align with the Alaska Exotic Plants Information Clearinghouse (AKEPIC; https://accs.uaa.alaska.edu/invasive-species/non-native-plants/) submission template.

Tabular data set summarizing detection and location of invasive plants on islands in Alaska Maritime National Wildlife Refuge between July 14, 2024 and July 31, 2024. Data has been reformatted from its original format to align with the Alaska Exotic Plants Information Clearinghouse (AKEPIC; https://accs.uaa.alaska.edu/invasive-species/non-native-plants/) submission template.

The SSWP Non-Native Invasive Plants Study is one of many relicensing documents for the South SWP (SSWP) Hydropower Project Number 2426. The California Department of Water Resources and the Los Angeles Department of Water and Power applied to the Federal Energy Regulatory Commission for a new license of the SSWP Project located in Los Angeles County, California along the West Branch of the State Water Project (SWP). The SWP provides southern California with many benefits, including an affordable water supply, reliable regional clean energy, opportunities to integrate green energy, accessible public recreation opportunities, and environmental benefits.

Quantifying Western U.S. shrublands as a series of fractional components with remote sensing provides a new way to understand these changing ecosystems. The USGS NLCD team in collaboration with the BLM has produced the most comprehensive remote sensing-based quantification of Western U.S. shrublands to date. Nine shrubland ecosystem components, including percent shrub, sagebrush (Artemisia spp.), big sagebrush, herbaceous, annual herbaceous, litter, and bare ground cover, along with sagebrush and shrub heights, were quantified at 30-m resolution by mapping region. Each region required extensive ground measurement for model training and validation, two scales of remote sensing data from commercial high-resolution satellites and Landsat 8, and regression tree modeling to create component predictions. In the mapped portion (1,946,100 km²) of the total study area (2,557,556 km²), bare ground averaged 46.8%, shrub 14.4%, sagebrush 4.4%, big sagebrush 3.1%, herbaceous 22.8%, annual herbaceous 4.3% and litter 15.6%. Shrub height averaged 39.8 cm and sagebrush height 10.5 cm. Component accuracies using independent validation averaged R² values of 0.46, RMSE of 10.37 and nRMSE of 0.12, and cross validation averaged R² values of 0.72, RMSE of 5.09 and nRMSE of 0.062. Component composition strongly diverges by level III ecoregions, where 13 of 22 ecoregions are bare ground dominant, 8 are herbaceous dominant, and one is shrub dominant. Sagebrush physically covers 86,219 km², or 4.4%, of our study area, but it is present in 835,507 km², or 42.9%, of the non-masked area of our study area, underscoring its widespread distribution. This version contains some confusion between pinyon-juniper tree cover and shrubs. In a subsequent version, we have applied a more aggressive masking of tree canopy cover to each rangeland component. Specifically, we lowered the tree canopy cover threshold for exclusion from 40 to 25%. For pixels with 1-25% tree canopy cover we ensured that our primary components (shrub, herbaceous, litter, and bare ground) cover summed to 100% when added with the tree canopy. And, for the secondary components (sagebrush, big sagebrush, sagebrush height and shrub height) we reconciled to the primary component (shrub), excluding any pinyon-juniper woodlands. For the updated version with these changes applied, see https://doi.org/10.5066/P9MJVQSQ. This version of data were used as training for the Back-in-Time (BIT) fractional cover time series available at https://doi.org/10.5066/P9C9O66W. Component products can also be downloaded from www.mrlc.gov.

Quantifying Western U.S. shrublands as a series of fractional components with remote sensing provides a new way to understand these changing ecosystems. The USGS NLCD team in collaboration with the BLM has produced the most comprehensive remote sensing-based quantification of Western U.S. shrublands to date. Nine shrubland ecosystem components, including percent shrub, sagebrush (Artemisia spp.), big sagebrush, herbaceous, annual herbaceous, litter, and bare ground cover, along with sagebrush and shrub heights, were quantified at 30-m resolution by mapping region. Each region required extensive ground measurement for model training and validation, two scales of remote sensing data from commercial high-resolution satellites and Landsat 8, and regression tree modeling to create component predictions. In the mapped portion (1,946,100 km²) of the total study area (2,557,556 km²), bare ground averaged 46.8%, shrub 14.4%, sagebrush 4.4%, big sagebrush 3.1%, herbaceous 22.8%, annual herbaceous 4.3% and litter 15.6%. Shrub height averaged 39.8 cm and sagebrush height 10.5 cm. Component accuracies using independent validation averaged R² values of 0.46, RMSE of 10.37 and nRMSE of 0.12, and cross validation averaged R² values of 0.72, RMSE of 5.09 and nRMSE of 0.062. Component composition strongly diverges by level III ecoregions, where 13 of 22 ecoregions are bare ground dominant, 8 are herbaceous dominant, and one is shrub dominant. Sagebrush physically covers 86,219 km², or 4.4%, of our study area, but it is present in 835,507 km², or 42.9%, of the non-masked area of our study area, underscoring its widespread distribution. This version contains some confusion between pinyon-juniper tree cover and shrubs. In a subsequent version, we have applied a more aggressive masking of tree canopy cover to each rangeland component. Specifically, we lowered the tree canopy cover threshold for exclusion from 40 to 25%. For pixels with 1-25% tree canopy cover we ensured that our primary components (shrub, herbaceous, litter, and bare ground) cover summed to 100% when added with the tree canopy. And, for the secondary components (sagebrush, big sagebrush, sagebrush height and shrub height) we reconciled to the primary component (shrub), excluding any pinyon-juniper woodlands. For the updated version with these changes applied, see https://doi.org/10.5066/P9MJVQSQ. This version of data were used as training for the Back-in-Time (BIT) fractional cover time series available at https://doi.org/10.5066/P9C9O66W. Component products can also be downloaded from www.mrlc.gov.

Exotic plant patches detected on monitoring routes at Zion National Park, 2023

Exotic plant patches detected on monitoring routes at Zion National Park, 2023