Scientific interests

I am a palaeoecologist specialising in plant macrofossil analysis. My interests focus on vegetation history and palaeoecology in the late-glacial and Holocene (14,000 - 0 years ago) especially the vegetation responses to climate changes. I took up macrofossil analysis in 1970 and now have a wide experience in Europe and North America, with special emphasis on northern and arctic ecosystems.

I have worked on late-glacial sediments in Scotland, Norway, and Minnesota, on the Holocene in Svalbard, Greenland, and Tibet, and the full-glacial in Alaskan Beringia (between Alaska and Siberia) and Siberia. I have studied lake eutrophication and pollution in Minnesota, UK, and North Africa. I have investigated plant macrofossil dispersal in lakes and across the Norwegian tree-line. I have used the stomatal density of fossil leaves to reconstruct atmospheric CO2 concentrations during the late-glacial and the Holocene. I have researched on the use of terrestrial plant macrofossils for AMS radiocarbon dating to provide chronologies and I have used 14C in the late glacial to precisely date volcanic ash layers and to quantify the marine 14C reservoir age.

My palaeoecological approach has always been through the combined study of several ecological and climatic proxies. My first multi-proxy study was on eutrophication in Minnesotan lakes in 1970. More recently, the CASSARINA project combined analyses of diverse animal and plant remains with radiometric dating to assess recent pollution and ecosystem resilience and sustainability in North African lakes. The largest multi-proxy study was the Kråkenes Project involving 24 scientists from 5 countries, aiming to reconstruct the late-glacial and early Holocene ecosystem responses to the climate changes. This approach has been continued in the NORPAST and NORPEC projects which take a transect of late-glacial sites from southern to northern Norway to determine regional climatic development and gradients since deglaciation. Much information is now available from terrestrial and marine sites from Europe and the North Atlantic, and I am currently involved in a synthesis of the biotic responses to climate changes during the late glacial and early Holocene throughout this area within the COST Action INTIMATE (Integration of ice-core, marine, and terrestrial records 60-8 ka).

Major research achievements

1. A multi-disciplinary reconstruction of the late-glacial and early Holocene ecosystems, environments, and climate changes at Kråkenes Lake, western Norway. Besides aquatic and vegetational development, quantitative climate reconstructions were made and compared from 5 biological proxies and rates of environmental and climatic change were estimated. The project also included the establishment of a high-resolution late-glacial/early Holocene radiocarbon chronology, the determination of the calendar ages of the late-glacial/early Holocene transition, of the start of the Younger Dryas, and of the Vedde and Saksunarvatn tephras, and the changes in pCO2 during the late-glacial and early Holocene determined from the stomatal density of fossil Salix herbacea leaves that emphasised the differences from the ice-core CO2 record. At least 26 publications have been produced from the project, including a special issue of Journal of Paleolimnology (2000, 23).
2. Two pioneering studies of the modern deposition of plant remains in small lakes and across the Norwegian tree line.
3. A pioneering multi-disciplinary study of lake eutrophication in 1970.
4. Palaeoecological reconstructions of rapid changes in lakes in North Africa over the last 100 years (CASSARINA project).
5. Evaluation of the importance of plant macrofossil data in the interpretation of late-glacial floras, environments, and climate, particularly concerning historical biogeography of Arctic-Alpine plants and the absence of trees at the Norwegian coast during the late glacial.

Teaching

I teach undergraduates about Quaternary palaeoecology and I give graduates an introduction to plant macrofossil analysis.

Scientific Collaboration

I collaborate with numerous colleagues within the University of Bergen with botanical, geological, and zoological interests. I also collaborate with Norwegian colleagues at the Radiocarbon Dating Laboratory at Trondheim and with botanists at Oslo Natural History Museum.

I am affiliated to University College London as a Visiting Professor at the Environmental Change Research Centre. I have collaborated on several research projects such as the EU-CASSRINA project, the palaeoenvironment of northern Egypt, and recent lake ecosystem changes in the UK with scientists at the Centre. In addition, Viv Jones (ECRC, UCL) and Steve Brooks (Natural History Museum, London) collaborate in my current late-glacial research projects. At Royal Holloway College, University of London, I collaborate with John Lowe and Sean Pyne-O’Donnell in typifying and dating late-glacial tephra horizons in Scottish sediments. I worked with N. John Anderson (Loughborough) on the reconstruction of a lake ecosystem including its catchment through the Holocene in west Greenland. I was involved with Yan Zhao (Lanzhou) and Carl Sayer (London) in a project on representation of plant remains in recent lake sediments.

Other interests

I have a strong interest in photography of plants in the wild, and I particularly enjoy visiting alpine areas around the world to study their flora. My other major hobby is gardening, with a special interest in growing alpine plants.

Publications

My publications since 2005 are listed below. Details of my other publications can be found on the EECRG's publications web pages.

Birks, H.H. & Bjune, A.E. (2010) Can we detect a west-Norwegian tree-line from modern samples of plant remains and pollen? Results from the DOORMAT project. Vegetation History and Archaeobotany, 19, 325-340.

Birks, H.H. & van Dinter, M. (2010) Late-glacial vegetation and climate gradients in the Nordfjord-Ålesund area, western Norway. Boreas, 34, 783-798 (doi: 10.1111./j.1502-3885-2010.00161.x.).

Cotton, S. & Birks, H. (2010) Eastern Cape Odyssey. The Alpine Gardener, 78, 422-444.

Heggen, M.P., Birks, H.H. & Anderson, N.J. (2010) Long-term ecosystem dynamics of a small lake and its catchment in west Greenland. The Holocene, 20, 1207-1222. (doi: 10.1177/0959683610371995).

de la Riva Caballero, A., Birks, H.J.B., Bjune, A.E., Birks, H.H., & Solhøy, T. (2010) Oribatid mite assemblages across tree-line in western Norway and their representation in lake sediments. Journal of Paleolimnology, 44, 361-374.

Bakke J., Lie, Ø., Heegaard, E., Dokken, T., Haug, G.H., Birks H.H., Dulski, P. & Nilsen, T. (2009) Rapid oceanic and atmospheric changes during the Younger Dryas cold period. Nature Geoscience, 2, 202-205.

Larrasoaña, J.C., Ortuño, M., Parés, J.M., Birks, H.H., Valero-Garcés, B., Bordonau, J., & Copon, R. (2009) Mineral magnetic identification of Late Holocene environmental variations and seismic events in proglacial sediment of Lake Barrancs (Maladeta massif, Central Pyrenees, Spain. Palaeogeography, Palaeoclimatology, Palaeoecology, 294, 83–93. (doi:10.1016/j.palaeo.2009.04.003).

Väliranta, M., Birks, H.H., Helmens, K., Engels, S. & Piirainen, M. (2009) Early glacial interstadial summer temperatures were higher than today in north Scandinavia. Quaternary Science Reviews, 28, 777-782. (doi:10.1016/jquascirev.2009.01.004).

Birks, H.H. (2008) The Late-Quaternary history of arctic and alpine plants. Plant Ecology and Diversity, 1, 135-146.

Birks, H.H. (2008) Alpines on the Equator. The Alpine Gardener, 76, 426-435.

Birks, H.J.B. & Birks, H.H. (2008) Biological responses to rapid climate change at the Younger Dryas–Holocene transition – succession, diversity, turnover, and rates of change. The Holocene, 18, 19-30. (doi:10.1177/0959683607085572)

van Geel, B., Aptroot, A., Baittinger, C., Birks, H.H., Bull, I.D., Cross, H.B., Evershed, R.P., Gravendeel, B., Kompanje, E.J.O., Kuperus, P., Mol, D., Nierop, K.G.J., Pals, J.P., Tikhonov, A.N., van Reenen, G. & van Tienderen, P.H. (2008) The ecological implications of a Yakutian mammoth’s last meal. Quaternary Research, 69, 361-376.

Ammann, B., Birks, H.H., Walanus, A. & Wasylikowa, K. (2007) Late glacial multidisciplinary studies including plant macrofossils. Encyclopedia of Quaternary Science, (Editor-in-Chief S.A. Elias). Elsevier B.V. 2477-2485.

Birks, H.H. (2007) Plant macrofossils in palaeoecology – an overview. Encyclopedia of Quaternary Science, (Editor in Chief S.A. Elias). Elsevier B.V. 2266-2288.

Birks, J., Birks, H., Jans, H., Everson, J., Thorne, D. and Thorne, M. (2007) The Alpine Garden Society in Tibet (2005). The Alpine Gardener, 75, 289-349.

Bjune, A.E., Birks, H.J.B. & Birks, H.H. (2007) Planter og fortidens klima. Ottar, Nr. 265, 2007, 32-38.

Gaillard, M.-J. & Birks, H.H. (2007) The contribution of plant macrofossil analysis to paleolimnology. Encyclopedia of Quaternary Science, (Editor-in-Chief S.A. Elias). Elsevier B.V. 2337-2355.

Birks, H.H. & Birks, H.J.B. (2006) Multiproxy studies in palaeolimnology. (In: Festschrift Brigitta Ammann. (Eds. W.O. van der Knaap, W. Tinner, A.F. Lotter, and S. Hicks). Vegetation History and Archaeobotany, 15, 235-251.

Birks, H.H., Larsen, E. & Birks, H.J.B. (2006) On the presence of late-glacial trees in western Norway and the Scandes: a further comment. Journal of Biogeography, 33, 376-377.

Bondevik, S, Mangerud, J., Birks, H.H., Gulliksen, S. & Reimer, P. (2006) Changes in North Atlantic radiocarbon reservoir ages during the Allerød and Younger Dryas. Science, 312, 1514-1517.

Eide, W. & Birks, H.H. (2006) Stomatal frequency of Betula pubescens and Pinus sylvestris shows no proportional relationship with atmospheric CO2 concentration. Nordic Journal of Botany, 24, 327-339.

Eide, W., Birks, H.H., Bigelow, N.H., Peglar, S.M. & Birks, H.J.B. (2006) Holocene tree migrations in the Setesdal valley, southern Norway, reconstructed from macrofossil and pollen evidence. Vegetation History and Archaeobotany, 15, 65-85.

Zhao, Y., Sayer, C.D., Birks, H.H., Hughes, M. & Peglar, S.M. (2006) Spatial representations of aquatic vegetation by macrofossils and pollen in a small and shallow lake. Journal of Paleolimnology, 35, 335-350.

Birks, H.H., Klitgaard Kristensen, D., Dokken, T.M. & Andersson, C. (2005) Exploratory comparisons of quantitative temperature estimates over the last deglaciation in Norway and the Norwegian Sea. In: Climate Variability in the Nordic Seas. (Eds. Drange, H., Dokken, T.M., Furevik, T., Gerdes, R. & Berger, W.). AGU Geophysical Monograph 159, pp 341-355.

Birks, H.H., Larsen, E. & Birks, H.J.B. (2005) Did tree-Betula, Pinus and Picea survive the last glaciation along the west coast of Norway? A review of the evidence, in light of Kullman (2002). Journal of Biogeography, 32, 1461-1471.