Ugotavljanje velikosti populacije sviščevega mravljiščarja Maculinea alcon (Lepidoptera:Lycaenidae) v povezavi z lastnostmi rastišč hranilne rastline v osrednji Sloveniji

Močilar, Mitja (author), Verovnik, Rudi (mentor)

Raziskava razširjenosti sviščevega mravljiščarja (Maculinea alcon) v osrednji Sloveniji in določitve stanja njegovih habitatov je bila opravljena zaradi določitve naravovarstvenih smernic, ki bodo omogočale ohranitev vrste v osrednji Sloveniji in na vseh podobnih območjih v Evropi. Podrobneje smo preiskovali območje v okolici Vrhnike. Ugotovili smo, da sta na območju Vrhnike prisotni dve populaciji, med katerimi nismo zasledili nobenih migracij, kar pa ni trden dokaz, da do migracij med habitatnimi krpami nikoli ne pride. Razlog za to je metodološki, saj z metodo markiranja težko odkrijemo redke migrante. Tudi naravne prepreke iz dreves in grmičevja, ki na nekaterih predelih segajo tudi do višine deset metrov, širine do pet metrov in so neprehodne, so pri tem ključne. Ugotovili smo tudi, da je gostota jajčec na manjši habitatni krpi večja. Prav tako je bila na slednji večja tudi gostota odraslih osebkov, vendar pa je bilo število odraslih osebkov kljub manjši gostoti večje na večji habitatni krpi. Na obravnavanem območju je glavni problem prezgodnja košnja, saj so bili mokrotni travniki pokošeni že konec junija, s tem pa je bil uničen velik delež hranilnih rastlin. Tudi večja gostota jajčec na manjši krpi je verjetno posledica košnje, saj so metulji primorani odlagati jajčeca na še preostale rastline. Da bi lahko sviščevega mravljiščarja na obravnavanem območju zaščitili, moramo habitate ohraniti v prvotnem stanju in zmanjšati količino uporabljenih gnojil in pesticidov na območjih okoli habitatov. Najenostavnejši ukrep za zaščito vrste bi bil enostaven premik košnje v konec avgusta, s čimer bi omogočili prehod gosenic iz hranilnih rastlin v mravljišča, s tem pa bi povečali že obstoječe populacije in nastajanje novih.

• Language: Slovenian
• Keywords: Lepidoptera
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: PEF - Faculty of Education
• Year: 2017
• PID: 20.500.12556/RUL-92866
• COBISS.SI-ID: 11608905
• Publication date in RUL: 24.08.2017

Secondary language

• Language: English
• Title: Population size of the Alcon Blue - Maculinea alcon (Lepidoptera: Lycaenidae) in realation to the characteristics of its host plant patches in central Slovenia

Abstract

The study of the Alcon Blue in central Slovenia and its habitats was conducted with the purpose to determine its current status and to provide guidelines for conservation in central Slovenia and in all similar habitats across Europe. We have closely examined the area around town Vrhnika. We discovered two populations in the area north of Vrhnika and detected no migration between them. This is however not conclusive evidence for the absence of the migrations between those two populations, as rare migrants are difficult to detect with the method we used. Lack of migrations despite proximity of both habitat patches can be attributed to thich hedges which are in some places 10 metres high. Estimated number of adults per patch was 94 for the larger and 64 for the smaller. Iinterstingly the density of eggs per plant was however twice higher in the smaller patch, whcih coincides with smaller number of host plants available. The females clearly prefered plants closer to the centre of the patch. We have discovered that density of eggs per plant is bigger on smaller habitat patches but the number of adult butterflies was lower on smaller habitat patch. The main conservation concerne in the study area is early mowing of majority of grasslands. Most of them were mowed at the end of june, which removed most of the flowering host plants in the area. Mowing is probably the main reason for higher density of eggs on smaller habitat patch, because butterflies are forced to lay eggs only on plants that were not cut down. To protect Alcon Blue on the area around Vrhnika, we must preserve the occupied habitats in its current state and lower the usage of fertilizers and pesticides in the neighbouring areas. In order to inprove the habitats and allow Alcon Blue to spread the simplest measure would be to perofrm mowing at the end of august, which would enable caterpillars to finalize their cycle at the host plants and move into the ant nests. With this simple measure we would increase the population size of the remaining populations and enable the formation of new populations nearby.

• Keywords: Lepidoptera