Silica algae reveal how ecosystems react to climate changes

Mar 09, 2009
Cyclotella, a fossil silica algae.

A newly published dissertation by Linda Ampel from the Department of Physical Geography and Quaternary Geology at Stockholm University in Sweden examined how rapid climate changes during the most recent ice age affected ecosystems in an area in continental Europe.

Rapid and extensive changes have taken place on several occasions in the past. For example, the latest (lasting from about 115,000 to 11,500 years ago) is characterized by several rapid and dramatic climate swings. These swings recurred in cycles of roughly 1,500 years and were originally discovered through studies of ice cores from Greenland in the early 1990s. These cycles started with an extremely rapid rise in temperatures, over just a few years or decades, of as much as 8-16C over Greenland.

Linda Ampel studied how these rapid cycles in the climate affected in an area in continental Europe. The study was based on analyses of sediment cores from an overgrown lake named Les Echets in eastern France and focuses on a time interval between 40,000 and 16,000 ago.

The findings are based on analyses of fossil silica algae, diatoms. Various species of diatoms prefer different relating to physical and chemical parameters such as temperature, salinity, access to nutrients, light, water depth, or available types of places to grow. These parameters, in turn, are affected by climate. Different species of diatoms can therefore indicate how the water environment changed as a consequence of the climate in the past.

analyses of the environmental archive from Les Echets, together with further analyses of chemical and biological parameters such as content of organic material and pollen grains from trees and other plants preserved in the lake, show that the ecosystems in the lake and its surroundings underwent marked changes during the latest ice age as a consequence of these 1,500-year cycles. The adaptation of the ecosystems prompted by the recurring warm periods took place as quickly as within 50 to 200 years.

“These findings show that ecosystems have changed rapidly in reaction to climate changes in the past, which indicates that quick adaptations could also take place in the future as a consequence of global warming, for instance,” says Linda Ampel.

Provided by The Swedish Research Council

Explore further: Sheep flock to Eiffel Tower as French farmers cry wolf

add to favorites email to friend print save as pdf

Related Stories

Small Organisms, Great Proxies

Oct 23, 2006

The present and past compositions of communities of single-celled algae in several Canadian lakes and their relationship to the known climate record suggest that these organisms and the lakes they reside in ...

Ice cores map dynamics of sudden climate changes

Jun 19, 2008

New, extremely detailed data from investigations of ice cores from Greenland show that the climate shifted very suddenly and changed fundamentally during quite few years when the ice age ended. Researchers ...

Ice core studies confirm accuracy of climate models

Sep 11, 2008

An analysis has been completed of the global carbon cycle and climate for a 70,000 year period in the most recent Ice Age, showing a remarkable correlation between carbon dioxide levels and surprisingly abrupt changes in ...

Climate Change Alters Base of Tahoe Food Web

Sep 29, 2008

(PhysOrg.com) -- UC Davis researchers at Lake Tahoe this week published the first evidence that climate change alters the makeup of tiny plant communities called algae, which are the very foundation of the ...

Recommended for you

How can we avoid kelp beds turning into barren grounds?

10 hours ago

Urchins are marine invertebrates that mould the biological richness of marine grounds. However, an excessive proliferation of urchins may also have severe ecological consequences on marine grounds as they ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.