The non-marine Ostracoda of Lapland: changes over the past century

• Published in: Journal of Limnology
• Main Authors: Anna Iglikowska, Tadeusz Namiotko
• Format: Article in Journal/Newspaper
• Language: English
• Published: PAGEPress Publications 2012
• Subjects: subarctic Ostracoda; peat bogs; Norway; Sweden; Finland; Arctic warming; Geography. Anthropology. Recreation; G; Physical geography; GB3-5030; Environmental sciences; GE1-350; Arctic; Bray; Subarctic; Lapland
• Online Access: https://doi.org/10.4081/jlimnol.2012.e26; https://doaj.org/article/85bb5bcef11043c2b1d8c8fca415c1ec

Novel faunistic data are presented from the poorly explored area of northern Lapland and comparisons are made between the present day ostracod diversity and historical records from a century ago. Twenty sites were sampled across Norwegian, Swedish and Finnish Lapland: eight to the west of the Scandinavian Mountain range, where the climate is milder under the influence of the Gulfstream, and 12 sites in the slope area east of these mountains, where the impact of the continental climate is stronger. The sample sites were mainly peat bogs fed by springs (the dominant habitat type in the study area), but also included helocrene springs, ditches, ponds and the littoral zone of lakes. In total 4376 individuals belonging to 16 species were collected. The most widespread and abundant species were Cyclocypris ovum , Candona candida and Pseudocandona rostrata , whereas Cyclocypris serena , Cryptocandona vavrai and Eucypris pigra were least abundant. The diversity of the ostracod assemblages to the west and to the east of the Scandinavian Mountains was significantly different, as measured by the Shannon diversity index. Mean values were 0.36 (western slopes) and 0.84 (eastern slopes). Three assemblage types were distinguished using UPGMA cluster analysis, with C. ovum , C. candida and P. rostrata as the three characteristic species. However, no statistically significant differences were revealed between the ostracod site assemblages when grouped geographically into west and east of the Scandinavian Mountains. Our results did not show any significant correlation between the Bray-Curtis similarity of the ostracod assemblages and the geographical separation between sites. The most marked difference in ostracod diversity between the present data and the records from the beginning of the 20th century seems to be a retreat of some Arctic species from the Lapland area and a shift of a few eurytopic species further to the north of Lapland. Possible factors influencing this shift are discussed.