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T9
Impact of vegetation shifts on invertebrate communities in arctic lakes
M. van Hardenbroek 1 *, E. Hopla 1 , P.G. Langdon 1 , M.E. Edwards 1 , and LAC team
members
1 School of Geography, University of Southampton, Highfield, Southampton S017 1BJ, United Kingdom
Over the last three decades, a northward increase in shrubs and boreal forest has been
observed in the arctic. This ‘greening’ is likely to be linked to warmer climate and is
expected to continue to change arctic landscapes. Lakes are strongly influenced by
landscape changes that occur in their catchment, but the effect of greening on arctic lakes
is largely unknown. To understand the effect of vegetation change on arctic lakes, we will
investigate past periods of known vegetation change and their influence on lake systems,
based on sedimentary archives from lakes across the Arctic.
In order to address these issues, we will first assess changes in vegetation by analysing
pollen, plant macrofossils, and charcoal. We will also look for changes in the input
nutrients into the lakes by XRF scanning and analyses of stable isotopes and C:N ratios of
sedimentary organic matter. Secondly, we will investigate how changes in the input from
the catchment are linked to productivity and diversity of lake ecosystems themselves by
analyses of loss-on-ignition, diatoms, cladocerans, chironomids, pigments, and remains of
aquatic vegetation. This poster will present some of the initial results from these analyses.
We will study lakes in three regions (Alaska, Greenland, Russia), and by replicating the
design in three lakes per region, we aim to provide insights in both spatial and temporal
patterns in the response of lakes to vegetation change across the Arctic.
Keywords: arctic; greening; vegetation; palaeolimnology; chironomids; cladocerans