Intensive Mowing Effect of One Patch on the Metapopulations of Two Phengaris Species

Abstract In the second half of the 20th century, change of land use in the name of intensive agriculture was one of the most important factors caused significant loss of butterfly diversity in Europe. Phengaris nausithous and Phengaris teleius belong among the flagship species associated with wet meadows and are directly threatened by the intensive agriculture practises or management abandonment. Due to their very specific lifecycle, they are closely linked to their habitats and appropriate mowing management on their patches is thus crucial for their survival. Our research took place in Dolní Labe, Děčín, Czech Republic, on 16 patches and has been performed using Mark-Release-Recapture since 2009. This paper will illustrate how intensive mowing management, applied on only one of the patches, which forms only 9.4% of total locality size, can influence the entire local Phengaris metapopulation. The selected patch was intentionally mowed in the middle of flight season annually for four years. Even though, no significant effect was identified after the first year of study, after the second and third seasons, there was evidence of population decline of both studied species.