| Abstract [eng] |
SUMMARY DISTRIBUTION OF DRAGONFLIES IN HABITATS OF SOUTHEASTERN PART OF LABANORAS REGIONAL PARK During the last 10- 15 years population numbers and frequency of records of southern and southeastern species have significantly increased in central Europe, and a northward range expantion of some of these species has also been noticed. Stenotopic species Aeschna crenata, Coenagrion johannsoni was observed in Lithuania. In the edition of Lithuanian Red Book in 2007 there are 13 species of dragonflies. Dragonflies are good indicators for the environmental quality in water habitats. Species dissapear because conditions in the habitats make worse or the habitats dissapear. Protection of dragonflies species is posibble just with protection of habitats. The investigation of dragonflies were carried out in Labanoras Regional Park in 2005- 2006. Some different habitats were selected: rivers (Žeimena, Lakaja, Peršokšna), eutrofic lakes (M. Siaurys, D.Siaurys, Ilgis, Peršokšnai), dystrophic lakes (Petrežeris, Akutė, Verpstinis, Bežuvis). The 43 species of dragonflies were registered in investigated areas. Lakaja river larvae and exuvia species complex is similar to Peršokšna river. These two rivers were similar in substrate type. Žeimena river adults species complex is similar to Lakaja river. All lakes were compared with larvae and exuvia complexes. There are found 36 species in lakes habitat. To compare all habitats I calculated Shannon biodiversity index. In Lakaja river there is the highest biodiversity of larvae and exuvia (H= 2,9) and adults (H= 2,88). Big biodiversity in Lakaja river substrate types has influence on the abundance of larvae and exuviae. The highest biodiversity of adults was found in Bežuvis dystrophic lake (H= 3,49), of larvae and exuvia in M. Siaurio lake (H=3,05). Rivers and eutrofic lakes habitats are more similar then another habitats (Sorensen similarity index 0,44). The bigger differences was between rivers and dystrophic lakes (Sorensen similarity index 0,32). The best ecological state is in Peršokšna river, Akutė and Petrežeris dystrophic lakes. |
