Response of Pediastrum in German floodplain lakes to Late Glacial climate changes

authored by

Falko Turner, Richard Pott, Anja Schwarz, Antje Schwalb

Abstract

Subfossil remains of the Pediastrum-algae group (Fam. Hydrodictyaceae) are frequently found in lake sediments, but very few studies have used them as palaeoclimate and palaeolimnological indicators. This study explored the species composition of Pediastrum assemblages in shallow floodplain lakes in northern Germany during two transitional periods from cold to temperate climate conditions (GS-2/GI-1 and GI-1/Holocene). We identified Pediastrum taxa to subspecies level and used multivariate statistics (constrained clustering, principal component analysis and redundancy analysis) to show that shifts in taxonomic composition reflected the strong Late Glacial climate oscillations. The Pediastrum assemblages indicate that climate amelioration already begun shortly before the main GS-2/GI-1 summer-temperature transition. In contrast to previous studies that identified trophic state as the main driver of change in Pediastrum species composition, we identified climate shifts and related factors as the major drivers of community change. Water depth and trophic state probably acted as secondary factors that were responsible for differences in Pediastrum response between the first and second investigated climate transitions. During cold periods, Pediastrum algae composition was controlled mainly by environmental variables, whereas during warm periods, Pediastrum assemblages may have been influenced to a greater extent by intra- and intergeneric competition. This study contributes to knowledge about ecological niches of Pediastrum species. Size-measurements on Pediastrum coenobia reveal that one response of Pediastrum algae to climate shifts probably was size change. Coenobia of Pseudopediastrum boryanum var. boryanum were significantly smaller during cold climate periods than during temperate periods. The shifts in Pediastrum species composition and coenobium size suggest this algae group has great potential for enabling palaeoecological and palaeoclimate inferences.

Organisation(s)

Institute of Geobotany

External Organisation(s)

Chinese Academy of Sciences (CAS)
Technische Universität Braunschweig

Type

Article

Journal

Journal of paleolimnology

Volume

52

Pages

293-310

No. of pages

18

ISSN

0921-2728

Publication date

12.2014

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Aquatic Science, Earth-Surface Processes

Sustainable Development Goals

SDG 13 - Climate Action

Electronic version(s)

https://doi.org/10.1007/s10933-014-9794-2 (Access: Closed)