Oecologia

, Volume 160, Issue 3, pp 577–587

Relative contributions of local and regional factors to species richness and total density of butterflies and moths in semi-natural grasslands

  • Juha Pöyry
  • Juho Paukkunen
  • Janne Heliölä
  • Mikko Kuussaari
Community Ecology - Original Paper

DOI: 10.1007/s00442-009-1328-7

Cite this article as:
Pöyry, J., Paukkunen, J., Heliölä, J. et al. Oecologia (2009) 160: 577. doi:10.1007/s00442-009-1328-7

Abstract

Metapopulation theory predicts that species richness and total population density of habitat specialists increase with increasing area and regional connectivity of the habitat. To test these predictions, we examined the relative contributions of habitat patch area, connectivity of the regional habitat network and local habitat quality to species richness and total density of butterflies and day-active moths inhabiting semi-natural grasslands. We studied butterflies and moths in 48 replicate landscapes situated in southwest Finland, including a focal patch and the surrounding network of other semi-natural grasslands within a radius of 1.5 km from the focal patch. By applying the method of hierarchical partitioning, which can distinguish between independent and joint contributions of individual explanatory variables, we observed that variables of the local habitat quality (e.g. mean vegetation height and nectar plant abundance) generally showed the highest independent effect on species richness and total density of butterflies and moths. Habitat area did not show a significant independent contribution to species richness and total density of butterflies and moths. The effect of habitat connectivity was observed only for total density of the declining butterflies and moths. These observations indicate that the local habitat quality is of foremost importance in explaining variation in species richness and total density of butterflies and moths. In addition, declining butterflies and moths have larger populations in well-connected networks of semi-natural grasslands. Our results suggest that, while it is crucial to maintain high-quality habitats by management, with limited resources it would be appropriate to concentrate grassland management and restoration to areas with well-connected grassland networks in which the declining species currently have their strongest populations.

Keywords

Habitat connectivity Local habitat quality Metapopulation Partitioning methods Patch area 

Supplementary material

442_2009_1328_MOESM1_ESM.doc (646 kb)
Supplementary materials (DOC 646 kb)

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Juha Pöyry
    • 1
  • Juho Paukkunen
    • 1
  • Janne Heliölä
    • 1
  • Mikko Kuussaari
    • 1
  1. 1.Finnish Environment InstituteResearch Programme for BiodiversityHelsinkiFinland

Personalised recommendations