Epsilon Open Archive

Abstract

Monitoring of butterflies is most often only directed towards the grassland fauna.
Species associated with other vegetation types, as well as the impact of the surrounding
landscape, often become neglected. The aim with this study was, in contrast, to
perform a novel landscape-based monitoring method for butterflies in diverse
vegetation types and more specifically
(i) evaluate the impact of environmental variables on butterfly abundance, (ii) compare
the distribution of butterflies in different vegetation types and (iii) analyse and improve
the monitoring method. Eight randomly placed study sites (750 m x 750 m) located in
south eastern Sweden were used. The vegetation composition inside the squares had
been assessed using aerial photos. Tree cover had largest impact on butterfly
abundance with a negative linear relationship between abundance and increasing tree
cover. Clear-cuts were the vegetation type harbouring the overall highest abundance
and diversity of butterflies. In semi-natural grasslands, where the nationally-based
monitoring of butterflies in Sweden currently is being performed, only 42% of the
species were found, indicating a bias directed towards only a part of the species pool.
The novel kind of monitoring presented here, using a landscape context, can, if
performed regularly, increase our knowledge of how structural changes at landscape
level affect butterflies and thereby improve the conservation efforts.