Relative importance of host plant patch geometry and habitat quality on the patterns of occupancy, extinction and density of the monophagous butterfly Iolana iolas

摘要: Habitat fragmentation is a major cause of species rarity and decline because it increases local population extinctions reduces recolonisation rates remnant patches. Although two patch characteristics (area connectivity) have been used to predict distribution patterns in fragmented landscapes, other factors can affect the occurrence as well probability becoming extinct. In this paper, we study spatial structure dynamics butterfly Iolana iolas 75-patch network its host plant (Colutea hispanica) determine relative importance area, connectivity habitat quality on occupancy, extinction density over period 2003–2006. Occupancy 2003, incidence (proportion years occupied) were mostly affected by area. Smaller patches less likely be occupied they had higher extinction, partly due environmental stochasticity. The I. was negatively related area all years. Only 2004 positively influenced fruit production per plant. Our results suggest that for iolas, probably specialist butterflies with clearly delimited resource requirements, metapopulation satisfactorily predicted using only geometric variables most are subsumed However, hypothesis should subject further testing under diverse conditions evaluate extent generalisation.