Relation Between Butterfly Composition and Spread of Non-Native Plant Species at a Ramsar

Relation between butterfly composition and spread of non-native plant species at a Ramsar site Lonjsko polje, Croatia

Vlatka Mičetić1, Iva Mihoci2 and Igor Stanković3

1Group for Systematic Zoology and Entomology, Department of Biology, Faculty of Science, Rooseveltov trg 6, 10 000, Zagreb, Croatia;

2Croatian NaturalHistoryMuseum, Department of Zoology, Demetrova 1, 10000 Zagreb, Croatia

3Hrvatske vode, Department of Water Protection, Central Water Management Laboratory, Ulica grada Vukovara 220, 10 000 Zagreb

Abstract

LonjskoPoljeNatureParkis one of Europe’s largest remained intact wetland habitatswith its mosaic distribution of vegetation, seasonal flooding and traditional way of living.Dialog between water and land makes Lonjsko polje specific with different habitat types for different potential species.On a significant part of the Park there are landmine lefts and therefore cessation of cattle breeding and agricultural activity occurs. It results with spreading of non-native plant species. Butterflies are highly sensitive to habitat quality, management and fragmentation, local climate and vegetation structure. The primary objectives were to determine relation between butterfly composition and spread of non-native plantspecies (Amorpha fruticosa L., Asclepias syriaca L. and Ambrosia artemisifolia L.) on ten researched localities. Additional objectives included determining anthropogenic pressures, and war damage on both butterfly richness and composition.Researched localities were: Repušnica, Čigoč Mužilovčica I, Mužilovčica II, Lonja, Trebež, Bukovica, Livada Orlinci, Jasenovac and Poganovo polje. Sampling and laboratory analysis were carried out in two seasons during the warm and dry period in 2006 and 2007.Any of the sites were distinct with respect to the type of characteristic vegetation, duration of periodical flooding, land treatment and pollution with landmine lefts. Land treatment at localities is classified as mowing, grazing or combined (grazing/mowing) and by the vicinity of agricultural fields.Owing to the highest floristic and vegetation characteristics, and habitat diversity, the highest butterfly richness and highest diversity index was found at the locality Trebež. Trebež is locality with mosaic structure of habitats, with different durations of flooding. On some parts of Trebež mowing and pasturingoccurred. The present study confirmed that diversity of butterfly composition is higher at localities with native plant species than at localities with non-native plants A. fruticosa, A. artemisifolia and A. syriaca. Among localities with non-native plants, butterfly diversity is smaller at those with dominance of A. artemisifolia (Livada Orlinci) and both A. artemisifolia and A.fruticosa (Repušnica and Jasenovac). Butterfly diversity was higherat localities with only A. syriaca (Trebež and Lonja). Butterflies had plasticity with respect to host-plants, but adult butterflies could incorporate non-native flowering plants as a nectar source in their diet.Of all investigated sites, locality Poganovo polje was the most polluted one with landmine lefts. Therefore, on Poganovo polje was a significant overgrowth by non-native plant A. fruticosawhat resulted with lowest butterfly diversity. Also, on locality Poganovo polje, which is flooded during the whole season, didn’t occur any kind of human land treatment so succession of grassland was significant. It was confirmed that butterfly composition and richness were strongly influenced by habitat diversity.