Stable isotope response to lake eutrophication: Calibration of a high-resolution lacustrine sequence from Baldeggersee, Switzerland

Teranes, Jane L.; McKenzie, Judith A.; Lotter, André F.; Sturm, Michael (1999). Stable isotope response to lake eutrophication: Calibration of a high-resolution lacustrine sequence from Baldeggersee, Switzerland. Limnology and Oceanography, 44(2), pp. 320-333. American Society of Limnology and Oceanography. 10.4319/lo.1999.44.2.0320

[img] Text
LimnolOceanogr_44_320.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (602kB) | Request a copy

Stable isotope analyses of discrete seasonal layers from a 108-yr annually laminated freeze-core from Baldeg-gersee, a small, eutrophic lake in central Switzerland, provide information on the climatological and environmental factors, including lake eutrophication, that control oxygen and carbon isotopic composition of epilimnic biologically induced calcite precipitate.

During the last 100 yr, Baldeggersee has undergone major increases in productivity and eutrophication in response to nutrient loading from agriculture and industrialization in the lake's watershed. Calibration of the isotopic signal in Baldeggersee to historical limnological data quantitatively links evidence of isotopic depletion in the sedimented calcite to trophic state of the lake. δ18O values from the spring/summer “light” sediment layers steadily diverged to more depleted values in response to historical eutrophication: measured δ18O values were up to 21.5‰ more negative than calculated equilibrium δ18O values. Evidence for 13C depletion in the calcite, relative to equilibrium values, is more difficult to ascertain because of an overall dominance of isotopic enrichment in the dissolved inorganic pool as productivity in Baldeggersee increases. A positive association exists between the degree of oxygen-18 depletion and the calcite crystal size. Thus, large amorphous calcite grains can be used as a proxy for recognizing apparent isotopic nonequilibrium in sediment sequences from highly productive lacustrine environments from all geologic time scales.

In contrast to the light layers, the oxygen isotopic composition of the calcite in the late summer/fall “dark” sediment layers is unaffected by the apparent isotope nonequilibrium. Oxygen and carbon isotope values from the dark laminae in the Baldeggersee sediment therefore provide environmental and climatological proxies that can be calibrated with known environmental and regional climate data for the last century.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS) > Palaeoecology
08 Faculty of Science > Department of Biology > Institute of Plant Sciences (IPS)

UniBE Contributor:

Lotter, André Franz

Subjects:

500 Science > 580 Plants (Botany)

ISSN:

0024-3590

Publisher:

American Society of Limnology and Oceanography.

Language:

English

Submitter:

Peter Alfred von Ballmoos-Haas

Date Deposited:

02 Jun 2016 09:48

Last Modified:

02 Mar 2023 23:27

Publisher DOI:

10.4319/lo.1999.44.2.0320

BORIS DOI:

10.7892/boris.82857

URI:

https://boris.unibe.ch/id/eprint/82857

Actions (login required)

Edit item Edit item
Provide Feedback