title: Quantification of UV-B flux through time using UV-B-absorbing compounds contained in fossil Pinus sporopollenin.
abstract: UV-B radiation currently represents c. 1.5% of incoming solar radiation. However, significant changes are known to have occurred in the amount of incoming radiation both on recent and on geological timescales. Until now it has not been possible to reconstruct a detailed measure of UV-B radiation beyond c. 150 yr ago. Here, we studied the suitability of fossil Pinus spp. pollen to record variations in UV-B flux through time. In view of the large size of the grain and its long fossil history, we hypothesized that this grain could provide a good proxy for recording past variations in UV-B flux. Two key objectives were addressed: to determine whether there was, similar to other studied species, a clear relationship between UV-B-absorbing compounds in the sporopollenin of extant pollen and the magnitude of UV-B radiation to which it had been exposed; and to determine whether these compounds could be extracted from a small enough sample size of fossil pollen to make reconstruction of a continuous record through time a realistic prospect. Preliminary results indicate the excellent potential of this species for providing a quantitative record of UV-B through time. Using this technique, we present the first record of UV-B flux during the last 9500 yr from a site near Bergen, Norway.
authors.affiliation: Department of Zoology, University of Oxford, Oxford OX1 3PS, UK. kathy.willis@zoo.ox.ac.uk
authors.forename: K J
authors.initials: KJ
authors.lastname: Willis
authors.forename: A
authors.initials: A
authors.lastname: Feurdean
authors.forename: H J B
authors.initials: HJ
authors.lastname: Birks
authors.forename: A E
authors.initials: AE
authors.lastname: Bjune
authors.forename: E
authors.initials: E
authors.lastname: Breman
authors.forename: R
authors.initials: R
authors.lastname: Broekman
authors.forename: J-A
authors.initials: JA
authors.lastname: Grytnes
authors.forename: M
authors.initials: M
authors.lastname: New
authors.forename: J S
authors.initials: JS
authors.lastname: Singarayer
authors.forename: J
authors.initials: J
authors.lastname: Rozema
mesh_terms: D000042:Absorption; D001704:Biopolymers / Q000737:chemistry; D002338:Carotenoids / Q000737:chemistry; D003373:Coumaric Acids / Q000378:metabolism; D005060:Europe; D005580:Fossils; D008027:Light; D028223:Pinus / Q000737:chemistry*; D011058:Pollen / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D001704:Biopolymers; D003373:Coumaric Acids; C009800:sporopollenin; D002338:Carotenoids