Pronounced turnover of vascular plant species in Central European arable fields over 90 years

We studied changes in vascular plant species occurring in Central European (Germany, Czech Republic, Slovakia, Switzerland, Liechtenstein, Austria, Hungary, Northern Italy, Slovenia and Croatia) arable fields and their edges from 1930 to 2019. To correct for bias in the data, we used occupancy modeling to analyze changes in the occupancy, i.e., distribution ranges sizes, of the 359 most common species in the AgriWeedClim database. We used ecological indicator values, native versus alien (archaeophyte, neophyte) status, and species affinity to arable habitats to assess changes in the occupancy of species with different environmental preferences and biogeographic origins. We found only a small decline in overall species occupancy over time, with a median occupancy change of −0.1 %, possibly due to the exclusion of rare species from modeling. Species turnover was more pronounced, with 72 species decreasing to less than half of their initial occupancy and 77 species more than doubling their initial occupancy. Species with environmental preferences for nutrient-rich sites with neutral pH increased in occupancy whereas species typical for arable fields decreased. No response to climate change (i.e., increased occupancy of thermophilous or drought-tolerant species) was detected. Archaeophytes and native species decreased whereas neophytes increased in occupancy. Taken together, results suggest that the biodiversity of arable fields is changing largely in response to anthropogenic habitat changes.