Elinor Andrén, Associate Professor in Physical Geography
My research focus is paleoecology using fossil diatoms preserved in lake or sea sediments in combination with geochemical analyses and various dating methods to identify natural or human induced changes in the environment such as salinity, climate, pH, nutrients and shore displacement. I have been involved in developing transfer functions (the projects MOLTEN and DEFINE) to quantify and reconstruct background nutrient conditions in the Baltic Sea coastal zone to enable the implementation of EUs Water Framework Directive.
Since 2004, I am lecturer in Physical Geography at the School of Natural Sciences, Technology and Environmental Studies at Södertörn University. I mainly teach Environmental Science at the courses Processes in Nature, Applied Physical Geography, and The Baltic Seas Ecosystem and Natural Resources.
Deliberate removal of forests, achieved by cutting or fire, has been one of the most significant ways in which humans have modified the environment. Less well known are the environmental effects of historical changes in land-use, especially when it comes to the ecosystem response in coastal and open parts of the Baltic Sea. The aim of this project is to disentangle the long-term (from Neolithic, some 6000 years ago) role of human impact (through the periods of expansion, deforestation, erosion versus the periods of recession, reforestation) and natural driven processes (e.g. earlier climate change and isostatic uplift) to determine the mutual significance of the multiple stressors resulting in events of eutrophication and hypoxia in the Baltic Sea. The geographical focus is put on the Baltic Sea coastal zone in order to investigate how the ecosystem has responded to changes in land-use, as well as the other way around; how humans adapted to changes in the configuration of the landscape (e.g. shifting shorelines). Selected area for the case study is Gamlebyviken, a rural coastal area exceptionally rich regarding prehistoric remains. Our study is multidisciplinary and has a unique combination of expertise in both paleoecology and maritime archaeology as well as close collaboration with Västerviks museum.
Baltic coastal environment the last 2000 years
One of the most serious problems of the Baltic Sea today is the spread of hypoxic bottoms that reduces the already low biodiversity. There are gaps in knowledge about the historical extent of oxygen-free bottoms in the Baltic Sea coastal zone and how marine ecosystems recover after long periods of hypoxia. In the research project UPPBASER (Understanding Past and Present Baltic Sea Ecosystem Response - background for a sustainable future) long sediment cores from the Baltic coast are analysed for diatoms and geochemistry within the time interval the past 2000 years. The purpose is to study how land use changes are reflected in the sediments from the coastal zone and if there is synchronicity in recorded changes between coastal areas and the open Baltic Sea. A major advantage of using coastal sediment cores is the possible availability of terrestrial macro fossils to date and establish reliable age models that enable regional comparisons with other environmental archives.
The paleoenvironment of the Baltic Sea
Baltic Sea contains sediment archives that enables studies of past climate and environmental change. During autumn 2013 the International Ocean Discovery
Program (IODP) Expedition 347 Baltic Sea Paleoenvironment drilled several sites in the Baltic Sea in order to collect long sediment cores. I participate as diatom specialist in the Science Party together with 30 researchers from 12 different countries. My research focuses on the role of climate-driven processes affecting the Baltic ecosystem (changes in temperature, precipitation, salinity, primary production and oxygenation) and how these are recorded in the sediment archives. Detailed diatom analyses will be performed on unique sediment records from the deepest part of the Baltic Basin, the Landsort trench, and the Bornholm Basin, within the research project Late Pleistocene and Holocene forcing on the Baltic Sea.
Holocene development of Kamchatka
I participated in the Swedish polar expedition Beringia 2005 to the peninsula of Kamchatka in eastern Russia organized by the Swedish Polar Research Secretariat. The peninsula was prohibited military territory until the collapse of the Soviet Union in early 1990s and has a sparse population of about 400,000 contributing to the preservation of a relatively unexplored and pristine terrain. The project aims to use lake sediments and peat sequences to interpret climate and environmental development of Kamchatka in the last 10,000 years. The sampled material is analyzed for diatoms, pollen, chironomids, stable isotopes, volcanic tephras and testate amoebaes, in close collaboration with researchers from Lund University, Queens University of Belfast, University College London, Natural History Museum in London and Alfred Wegener Institute in Germany.