Land-use history exerts long-term effects on the clear-cut flora in boreonemoral Sweden.

Questions Can signs of 19th century grassland management, which can be observed in the flora immediately (2-4 yrs) after clear-cutting in boreonemoral Sweden, still remain 4 yrs later? Do the effects from the time since clear-cutting differ between forest and grassland plant species? Location Province of Östergötland, southern Sweden. Methods Twelve contemporary clear-cut areas that were once meadows and 12 that were once forests were selected using land-use maps from the 1870s. Grasses and herbaceous plants were surveyed twice, once in 2009 and once in 2013 (2-4 and 6-8 yrs after clear-cutting, respectively). Plant presence was recorded within 100 circular sample plots (radius 1 m) placed evenly throughout each respective clear-cut area along transects spaced 25-m apart. The number of sample plots in which a species was present was taken as a measure of that species' frequency. Random effects meta-analysis, odds ratios and ANCOVA were used to analyse species responses to clear-cutting over time. Results A total of 170 plant species were found in the study, of which 33 were classified as grassland indicator species and 31 as plants primarily confined to forests. Clear-cut areas with a history as meadowland had, on average, up to 64% higher total species richness and 110% more grassland indicator species than did clear-cut areas with a history as forest. The time since clear-cutting had no effect on total species richness. However, the odds of finding a grassland indicator species decreased with the time since clear-cutting, whereas the odds of finding a forest species increased. Conclusions We concluded that land-use history plays an important role in explaining the flora found in Swedish clear-cuts, and that its effects on species richness remain for a minimum of 8 yrs after harvest (conservative estimate). This phenomenon highlights the importance of acknowledging land-use legacies in ecological research and conservation. Future studies should investigate various options for the promotion of grassland plants in clear-cuts with a history of grassland management while also acknowledging the potential conflicts between conservation and production. The results may pertain to other countries with similar land-use histories. [ABSTRACT FROM AUTHOR]