Conterminous U.S. data used for modeling non-native vascular plant first records 1780-2022

This dataset was used for modeling the spatial distribution of first records of non-native plants in the conterminous U.S. The input dataset (alldata_input_frdm.csv) contains 4,763 rows of data, representing 1,538 counties in the contiguous U.S., 25 decades, and 3,389 first records of invasive terrestrial plant species (Williams et al., 2024) found in the US-RIIS list (Simpson et al. 2022, ver. 2.0). Our dataset includes 12 predictor variables likely to be associated with first record locations, such as human presence, climate, human transportation vectors, and biological or academic institutions. These input data were used to create a first records distribution model (FRDM), an application of species distribution modeling methods to the collection of species' first documented occurrences. See the "Process Step" section for more details on how these data were obtained and subsequently used. In addition to the main data frame used to generate the FRDM, this data bundle also includes five of the 12 raw predictor data at a county extent. These five predictors were manually compiled from various data sources to yield the most accurate aggregated version of these data. These predictor inputs include:
1) BotanicalGardens_county.csv, which contains information about state, county, and founding year of institutions classified as botanic gardens.
2) Cemeteries_Per_County.csv, which contains the number of cemeteries for each county within the conterminous United States.
3) Herbaria_county.csv, which contains information on affiliated institution, city, county, and state for herbaria in the conterminous United States.
4) historical_county_populations.csv, which is a digitized record of county population for each decade for all counties in the United States, from 1790-2010.
5) Universities.csv, which contains geographic information (state, county, and city), enrollment, and founding dates when available for universities and colleges in the conterminous United States.
References:
Simpson, A., Fuller, P., Faccenda, K., Evenhuis, N., Matsunaga, J., and Bowser, M., 2022, United States Register of Introduced and Invasive Species (US-RIIS) (ver. 2.0, November 2022): U.S. Geological Survey data release, https://doi.org/10.5066/P9KFFTOD.
Williams, D.A., Jarnevich, C.S., Sofaer, H.R. and Shadwell, K.S., 2024, First and Second Record of US-RIIS Vascular Plant Species in Contiguous United States: U.S. Geological Survey data release, https://doi.org/10.5066/P13GAYQA.