The Varying Radiocarbon Activity of Some Recent Submerged Estonian Plants Grown in the Early 1990s
Year: 2001
Type: article
Abstract: Eleven samples of aquatic plants from three Estonian lakes were analyzed for their radiocarbon content in a collaboration between the laboratories in Tallinn and Uppsala. δ 13 C values for the actual species were compiled to allow normalization of activities measured in Tallinn without δ 13 C values. The range for well determined species is usually a few per mil and the statistical uncertainty ≥1‰. δ 13 C values vary considerably for different Potamogéton species and Myriophýllum spp. Lake Äntu Sinijärv and Lake Päidre are hard-water lakes containing 300 and 200 mg HCO 3 – /L, respectively. One sample consisted of a carbonate crust deposited on a Ceratophýllum demersum plant in L. Äntu Sinijärv. Its Δ 14 C value was −147.3 ± 6.7‰ in 1990, whereas the plant had a value of −74.1 ± 8.0‰ (δ 13 C = −35.0‰). The same species in L. Päidre had a Δ 14 C value of +8.0 ± 8.8‰ (δ 13 C = −25.2‰) in 1992. Other species in L. Päidre contained more 14 C, from a Δ 14 C value of about +30‰ to about +155‰, the latter value measured in Tallinn on floating leaves of Nuphar lútea, close to that of the contemporaneous atmospheric CO 2 . In the third lake, Lake Punso, containing ≤30 mg HCO 3 – /L, the stems of Nuphar lútea exhibited in 1990 a memory effect: the activity, Δ 14 C = 209.6 ± 10.3‰, significantly exceeded that of the contemporaneous atmospheric CO 2 . However, the floating leaves of the same plant had the Δ 14 C value 143.1 ± 10.0‰, close to the atmospheric 14 C level in 1990. The memory is explained by nutrients stored in the root stock, used when the growth starts.
Source: Radiocarbon
Authors: Ingrid U Olsson, Enn Kaup
Institution: Uppsala University
Language: English
Subfield: Paleontology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W331372991