Patch distribution and dispersal limitation of four plant species in Swedish semi-natural grasslands

This study examined whether the patch distribution of four plant species Agrimonia eupatoria, Carlina vulgaris, Hypochoeris maculata and Plantago media were affected by dispersal limitation. Analysis of the patch size/isolation relationship was combined with a seed sowing experiment examining the recruitment of the species. Patch size was negatively correlated to isolation in Carlina, Hypochoeris and indicating that dispersal processes might affect the distribution pattern. Patch size of Agrimonia was not correlated, or in one case positively correlated, to isolation. Agrimonia was also the only species among the four where the recruitment not was affected by disturbance treatment or locality. The recruitment of Carlina, Hypochoeris and Plantago was higher in disturbed plots compared to undisturbed, and the latter two species were also affected by locality. This suggests that Agrimonia is less sensitive to isolation (and the ongoing fragmentation of the landscape) compared to the other three species, probably due to better dispersal and recruitment ability. We conclude in a discussion how different management strategies could serve to maintain viable populations of these species.