Table 1 Details on the datasets for each region used in this study
From: Many plants naturalized as aliens abroad have also become more common within their native regions
Region | Data source | Early period | Later period | Total number of grid cells | Size of grid cell | Number of native species used in analysis |
|---|---|---|---|---|---|---|
Austria | Floristische Kartierung Österreichs74 | before 1990 | 1990–2022 | 2600 | 5′ × 3′ (c. 6.25 × 5.55 km2) | 2419 |
Czech Republic | Pladias Database of the Czech Flora and Vegetation (http://www.pladias.cz)75 | before 2000 | 2001–2022 | 2551 | 5′ × 3′ (c. 6.25 × 5.55 km2) | 1834 |
Denmark (southeastern regions) | 1857–1883 | 2015 | 263 | 5 × 5 km2 | 921 | |
Flanders (northern Belgium) | 1939–1971 | 1972–2004 | 985 | 4 × 4 km2 | 861 | |
Germany | 1960–1987 | 1997–2017 | 12024 | 5′ × 3′ (c. 6.25 × 5 km2) | 1715 | |
Great Britain | Plant Atlas 202077 | 1970–1986 | 2000–2019 | 2852 | 10 × 10 km2 | 1355 |
Ireland | Plant Atlas 202077 | 1987–1999 | 2000–2019 | 1007 | 10 × 10 km2 | 910 |
The Netherlands | Nationale Databank Flora en Fauna78 | before1990 | 1990–2022 | 1685 | 5 × 5 km2 | 1115 |
Switzerland | Infoflora (The National Data and Information Center on the Swiss Flora; https://www.infoflora.ch/)79 | before 2000 | 2000–2022 | 1827 | 5 × 5 km2 | 2307 |
Thiérache(northern France) | 1880–1900 | 1957–2005 | 129 | 4 × 4 km2 | 775 |
