Responses of Regional Vegetation and Peatland Ecosystems to Climate Change Over the Last Millennium in the Western Lowlands of Kamchatka, Russia
Abstract
Climate in high-latitude regions has warmed rapidly over the recent decades, causing widespread changes in sea-ice cover and terrestrial ecosystem dynamics such as greening of the Arctic. However, regional patterns of ecosystem response to warming are still poorly understood in several regions of the Arctic due to data gaps. In particular, we still lack detailed records in the Far East of Russia in terms of regional vegetation and peatland responses to recent warming. Kamchatka, located between the Sea of Okhotsk and the Pacific Ocean, is an ideal region for studying climate and ecosystem change due to minimum human impacts. Here we present multi-proxy data from a peat core (core KAM12-B1; 53.9146° N, 155.9361° E; approximately 1 km from the Sea of Okhotsk at an elevation of 15 m) in the western lowlands of Kamchatka to investigate regional vegetation and peatland responses to climate change during the last millennium. Chronology of the 1-m-long peat core was controlled by 7 AMS 14C dates, covering the last 900 years. Pollen analysis shows a ca. 10% decrease in tree pollen (mostly tree birches) at 1600-1900 AD, while macrofossil results show an increase in brown mosses (Drepanocladus sp.) during the same period. These ecological changes suggest a cool and possibly wet climate in a period corresponding to the widely documented Little Ice Age (LIA). The peatland also shows a slight decrease in carbon accumulation during the LIA. The most pronounced changes in the record have occurred since 50 years ago (post-LIA) and include (1) an increase in the abundance of pollen from warm-adapted tree species, including Betula ermanii (stone birch) and Betula platyphylla (white birch); (2) the dominance of peat mosses (Sphagnum) in macrofossil assemblages suggesting a drying trend due to climate or successional change; and (3) higher carbon accumulation rates. Taken together, these results from the pollen-based regional vegetation reconstruction and the macrofossil-based local peatland suggest that upland and lowland ecosystems in Kamchatka have been sensitive to climate change over the last millennium, including the warming climate in the recent decades. Such studies can help to better understand ecosystem responses in the high-latitude regions to continued climate warming in the future.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFMPP13C1903C
- Keywords:
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- 0473 BIOGEOSCIENCES Paleoclimatology and paleoceanography;
- 0497 BIOGEOSCIENCES Wetlands;
- 4950 PALEOCEANOGRAPHY Paleoecology