Pollen Chemistry as the Next Generation Tool in Palaeoecological Research - Theory, Methods and Application

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2016

End date

12/31/2021

Budget

861,000 EUR

Fundings

Abstract

Pollen produced by plants can be preserved in the sediments of lakes and bogs for thousands, or even millions of years. When this happens, the youngest is preserved in the top layers of the sediments, and older pollen is buried deeper and deeper. If the plant communities in the surrounding environment have changed, then so too will the pollen in the sediments. This pollen provides a window into past ecosystem changes in the past. Because we generally lack information on past ecosystem changes beyond the last 100-200 years, pollen datasets vital sources of data for learning about how plants responded to environmental changes in the past, how this affects present-day patterns of biodiversity, and how plants might respond to environmental changes (e.g. climate changes) in the future. In PollChem we were investigating a new technique for the analysis of fossil pollen grains. The overall aim of the project was to investigate whether the chemical changes in fossil-pollen grains could be used to unlock secrets about past ecosystems. At the onset of the project, a number of studies had indicated that the chemical composition of pollen responds to changes in environmental conditions (e.g. exposure to solar UV-B radiation). This is exciting, because although solar UV-B radiation may be a key variable for understanding drivers of biodiversity change in the past, it is presently impossible to reconstruct UV-B radiation beyond the past few decades. Pollen chemistry could be an extremely valuable tool for Earth scientists for understanding how and why species evolve and even go extinct over time. But before we applied pollen chemistry to reconstruct the past it was crucial to understand how pollen chemistry responds to changes in UV-B radiation in the modern environment. In PollChem we developed a new set of experimental approaches and studies to estimate how plants respond to UV-B radiation, and made some major leaps forward towards applying pollen chemistry methods to ancient-sediment sequences. In addition, studies had also demonstrated that different species of plants had different pollen-chemistry characteristics. This means it might be possible to use chemical variations in pollen to identify grains to species/ genus level. This would give palaeoecologists a new tool for reconstructing past environments. In PollChem we showed that pollen-chemistry techniques can resolve differences at the sub-genus level within the group, oaks, using modern pollen, and investigated the best methods and protocols to apply this understanding to fossil sequences.