Assessment of habitat restoration for the conservation of Phengaris teleius butterfly

B.Sc. Cristina González Sevilleja

Master's thesis

Abstract:

This master thesis is part of the LIFE+ Project “Blues in the Marshes” that is carried out in a N2000 nature reserve in the South of the Netherlands. The project aims to restore the habitat of a threatened butterfly species: Phengaris teleius. This butterfly is threatened in Europe and its recovery is difficult due to its complex ecological relations with other species. The butterfly has only one host plant, Sanguisorba officinalis, and a myrmecophilous parasitic relation with Myrmica scabrinodis ants. Females lay eggs on the host plant and after hatching and developing into the 4th larval instar within only four to five weeks, the caterpillar is adopted by Myrmica ants, where it will develop inside the ant nest until the adult phase. The populations of both, ant and host plant, should be in stable conditions to carry the burden of the parasitic P. teleius population in the area. In the Netherlands, the target vegetation is a threatened N2000 habitat type belonging to the Cirsio-Molinietum community, occurring in fens and damp meadows. This ecosystem has declined in Europe; therefore conservation efforts are addressed to enlarge the area, also in the Netherlands. Within the LIFE+ Project, an experiment has been conducted to improve the ecosystem and consequently the ecological relations of P. teleius. In restoration areas, the soil was excavated to achieve nutrient-poor conditions and hay cut from wet meadows with climax vegetation communities was spread to re-establish the seed bank. In addition, to enhance the probabilities of success, sod translocations were done from climax vegetation to extend and restore wetland plants in the area and to attract Myrmica ants. Data of vegetation and ant occurrence from three consecutive years are analysed in this study to determine the short-term effects of restoration. Some signals of recuperation are observed within two years of research; vegetation composition is changing and several characteristic species of wetlands appeared in the restored areas. Vegetation coverage is increasing and soil conditions are going towards wetland situation. With respect to the ant population, M. scabrinodis is slowly spreading from the translocated sods and appearing in further areas. The target ant coexists with the competitor Lasius niger in some plots, where habitat conditions allow M. scabrinodis to colonize. The restoration process presents some positive signals of recuperation just after three years from soil excavation, but it still needs time for the colonization of ants and the total establishment of wetland plants.

Keywords

fen meadows, Phengaris butterfly, Myrmica ant, restoration methods

Language used: English

Date on which the thesis was submitted / produced: 10. 12. 2017

Thesis defence

• Supervisor: doc. Mgr. Jan Růžička, Ph.D.
• Reader: Tomáš Kadlec, Mgr.

Czech University of Life Sciences Prague

Faculty of Environmental Sciences

Master programme / field:
Engineering Ecology / Nature Conservation