Download Monitoring of dragonflies listed in the EU´s habitat

Monitoring of dragonflies listed in the EU´s habitat directive in
Sweden
Tommy Karlsson
Länsstyrelsen Östergötland, 581 86 Linköping
The member countries in the European Union are obliged to report the conservation
status for species listed in habitat directive every 6th year. To gather information about
population sizes and trends for the species in Sweden, the Swedish Environmental
Protection Agency funds an action named “Biogeographical monitoring”. The County
Administrative Board of Östergötland has been assigned to coordinate the
biogeographical monitoring of dragonflies (Odonata) and diving beetles (Dytiscidae)
listed in the Habitat directive in Sweden. Monitoring programs for the species are under
development, and current proposals are here presented.
The dragonfly species listed in the habitat directive occurring in Sweden are Aeshna
viridis, Leucorrhinia albifrons, L. caudalis, L. pectoralis and Ophiogomphus cecilia. In
addition, Sympecma paedisca has been found at some localities the last decade, but
due to its´ recent establishment in Sweden, it is not yet subject for monitoring. Only O.
cecilia is nationally redlisted (Near Threatened).
Both Aeshna viridis and Ophiogomphus cecilia have quite well-defined habitats in
Sweden. A. viridis mainly occurs in eutrophic-mesotrophic lakes with the plant
Stratiotes aloides, while O. cecilia are restricted to some large rivers in the northeastern part of Sweden. The strategy for monitoring these species is to recurrent detect
occurrence of the species at about 20 localities (both with and without the species) by
searching for exuviae and/or larvae (A. viridis).
The Leucorrhinia species have large distribution areas in Sweden and there are
probably a large amount of unrecorded localities. Thus, they are believed to be more
or less common and probably demonstrating stable population trends. In addition,
they seem to have quite broad ecological amplitudes and occur in several different
habitats. Monitoring such species with limited means is a challenge! The Leucorrhinia
species will together with the diving beetles be monitored in a number of randomized
1*1 km squares. To optimize the chance of detecting the species, both imagos as well
as larvae and exuviae will be sought after.
Furthermore, to increase observations of the species from the public, they are noted in
an information campaign by the Swedish Species Information Centre, the County
Administrative Board of Östergötland, and the Swedish Dragonfly Society.
Determination, ecology, distribution and lack of knowledge are described in folders for
every species.