Plants on the Polish-Belarusian border in Białowieża Forest

In late summer (August-September) 2024, plants growing along the PL-BY border in Białowieża Forest were inventoried. We sampled in dry, mesic and wet habitats in two locations each along the border for a total of 6 sample sites. Non-forest, thermophilic, pioneer, alien and invasive species were recorded. Transects were 800 meters long made up of 8 100m-long segments. In addition to sampling along the border, we also sampled plants along parallel 800m-long transects inside the forest 50m from the border to understand which species detected on the border may be colonizing the forest. On transects directly along the border, we recorded if plants occur on the forest edge, within the secondary barriers (forest net and concertina), along the border road—forest side, and/or along the border road—main barrier side. On transects both along the border and 50m inside the forest, we recorded abundance on a scale of 1-8 representing 1 individual, up to 10 individuals, 10, more than 10, up to 100, more than 100, up to 1000, more than 1000. Data analysis and publication are pending. A subset of these data have been included in a report to the The Institute of Environmental Protection – National Research Institute; the report is available at: https://ios.edu.pl/wp-content/uploads/2024/12/ekspertyza-oddzialywanie-zapory-granicznej.pdf and addresses the effects of border fortification on the Białowieża Forest World Heritage site. Note: the secondary barriers were constructed in December 2023 while the main barrier was constructed by July 2022.