Climatically driven pH changes in two Norwegian alpine lakes

Two alpine lakes in the south-central part of Norway have been studied for recent changes in diatom assemblages preserved in their sediments. Both lakes experience a post 1980 AD increase in diatom valve accumulation rates possibly reflecting an increase in lake productivity. In addition there is an...

Full description

Saved in:
Bibliographic Details
Published in:Journal of paleolimnology 2006-08, Vol.36 (2), p.175-187
Main Authors: Larsen, Jorunn, Jones, Vivienne J, Eide, Wenche
Format: Article
Language:English
Subjects:
Achnanthes minutissima
Achnanthes nodosa
Acid deposition
Acidification
Bacillariophyceae
Cations
Climate change
Cyclotella
Freshwater
Global warming
Holocene
Lakes
Mineralization
Mountain lakes
Navicula
Plankton
Pollutant deposition
Staurosirella
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Two alpine lakes in the south-central part of Norway have been studied for recent changes in diatom assemblages preserved in their sediments. Both lakes experience a post 1980 AD increase in diatom valve accumulation rates possibly reflecting an increase in lake productivity. In addition there is an overall increase in diatom-inferred pH at both sites. Recovery from lake acidification can be disregarded as a possible cause of increased pH as the lakes are situated in catchments with high buffering capacities in areas that have received low amounts of acid deposition. We suggest that recent climate warming has influenced both sites with the important effect of increasing mineralization in the catchments, resulting in greater fluxes of nutrients and base cations to the lakes, leading to an increase in diatom-inferred pH. Taxa that have increased in abundance include Achnanthes minutissima, Achnanthes nodosa, Cyclotella spp., Navicula schmassmannii, Staurosirella lapponica, and S. pinnata. In one of the lakes, the maximum diatom-inferred pH values reached at the top of the core are as high as pH values reconstructed from the diatom assemblages deposited at the end of the Mid-Holocene thermal maximum c. 4000 cal. BP.[PUBLICATION ABSTRACT]
ISSN:0921-2728
1573-0417
DOI:10.1007/s10933-006-0013-7