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Ecological Regime Shifts in Lake Kälksjön, Sweden, in Response to Abrupt Climate Change Around the 8.2 ka Cooling Event

Randsalu Wendrup, Linda LU ; Conley, Daniel LU ; Carstensen, Jacob; Snowball, Ian LU ; Jessen, Catherine and Fritz, Sherily (2012) In Ecosystems 15(8). p.1336-1350
Abstract
A detailed diatom record from Lake Kälksjön, west-central Sweden, reveals two periods of abrupt ecological change correlative with the 8.2 ka cooling event. Using a combination of abrupt step changes and piece-wise linear regressions, the diatom data were analysed for change points over time, and two sudden and large events that are described as regime shifts were detected. During the first event at c. 8040 cal. yr BP, a doubling in diatom biomass took place over 5-10 years time. This increase in primary productivity can be connected to an erosion event in the catchment that resulted in an abrupt increase in nutrient supply to the lake. The second event was characterised by a substantial shift within the planktonic diatom community from... (More)
A detailed diatom record from Lake Kälksjön, west-central Sweden, reveals two periods of abrupt ecological change correlative with the 8.2 ka cooling event. Using a combination of abrupt step changes and piece-wise linear regressions, the diatom data were analysed for change points over time, and two sudden and large events that are described as regime shifts were detected. During the first event at c. 8040 cal. yr BP, a doubling in diatom biomass took place over 5-10 years time. This increase in primary productivity can be connected to an erosion event in the catchment that resulted in an abrupt increase in nutrient supply to the lake. The second event was characterised by a substantial shift within the planktonic diatom community from taxa indicative of colder conditions to those indicating warm over 5-10 years at c. 7850 cal. yr BP. This event was superimposed on a successive change from periphytic to planktonic diatom dominance over a 250-year period and a gradual diversification of the periphytic community that spanned c. 150 years. Rapid climate warming following the 8.2 ka event likely caused these changes and both regime shifts are examples of externally driven abrupt ecological change.

This study demonstrates that it is possible to detect, quantify and test for regime shifts in paleoecological data, and it highlights the need for high sampling resolution and precise chronological control. High-resolution paleoecological reconstructions of ecological regime shifts in response to climate change can provide useful analogues of future changes in ecosystem structure and functioning. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
thresholds, regime shifts, lake sediment, varves, diatoms, Sweden, climate, Paleolimnology, 8.2 ka event
in
Ecosystems
volume
15
issue
8
pages
1336 - 1350
publisher
Springer
external identifiers
  • wos:000312143300010
  • scopus:84870616626
ISSN
1432-9840
DOI
10.1007/s10021-012-9588-1
project
BECC
language
English
LU publication?
yes
id
b24a6043-1fef-4c90-be98-a53c77fc3eb3 (old id 3233076)
alternative location
http://link.springer.com/article/10.1007/s10021-012-9588-1
date added to LUP
2013-01-17 16:05:00
date last changed
2017-11-12 03:42:20
@article{b24a6043-1fef-4c90-be98-a53c77fc3eb3,
  abstract     = {A detailed diatom record from Lake Kälksjön, west-central Sweden, reveals two periods of abrupt ecological change correlative with the 8.2 ka cooling event. Using a combination of abrupt step changes and piece-wise linear regressions, the diatom data were analysed for change points over time, and two sudden and large events that are described as regime shifts were detected. During the first event at c. 8040 cal. yr BP, a doubling in diatom biomass took place over 5-10 years time. This increase in primary productivity can be connected to an erosion event in the catchment that resulted in an abrupt increase in nutrient supply to the lake. The second event was characterised by a substantial shift within the planktonic diatom community from taxa indicative of colder conditions to those indicating warm over 5-10 years at c. 7850 cal. yr BP. This event was superimposed on a successive change from periphytic to planktonic diatom dominance over a 250-year period and a gradual diversification of the periphytic community that spanned c. 150 years. Rapid climate warming following the 8.2 ka event likely caused these changes and both regime shifts are examples of externally driven abrupt ecological change. <br/><br>
This study demonstrates that it is possible to detect, quantify and test for regime shifts in paleoecological data, and it highlights the need for high sampling resolution and precise chronological control. High-resolution paleoecological reconstructions of ecological regime shifts in response to climate change can provide useful analogues of future changes in ecosystem structure and functioning.},
  author       = {Randsalu Wendrup, Linda and Conley, Daniel and Carstensen, Jacob and Snowball, Ian and Jessen, Catherine and Fritz, Sherily},
  issn         = {1432-9840},
  keyword      = {thresholds,regime shifts,lake sediment,varves,diatoms,Sweden,climate,Paleolimnology,8.2 ka event},
  language     = {eng},
  number       = {8},
  pages        = {1336--1350},
  publisher    = {Springer},
  series       = {Ecosystems},
  title        = {Ecological Regime Shifts in Lake Kälksjön, Sweden, in Response to Abrupt Climate Change Around the 8.2 ka Cooling Event},
  url          = {http://dx.doi.org/10.1007/s10021-012-9588-1},
  volume       = {15},
  year         = {2012},
}