Owen Lewis
Dr Owen T. Lewis
RCUK Academic Fellow in Quantitative Biology
Tutorial Fellow in Biology, Brasenose College
Contacts
Dr Owen T. Lewis
Department of Zoology
University of Oxford
South Parks Road
Oxford OX1 3PS
UK
owen.lewis@zoo.ox.ac.uk
Tel:+44 (0)1865 271162
Fax: + 44 (0)1865 310447
Research Interests
I am a community ecologist and conservation biologist with a particular interest in tropical forest ecosystems. I have wide research interests, but my current research is focused on two main, interlinked themes. I welcome enquiries from well-qualified prospective graduate students interested in working in these areas.
(1) Ecology of tropical forests
I am interested in the processes that maintain and structure the astonishing diversity of tropical forests, and the impact of human activities (including fragmentation and commercial timber extraction) on the diversity and functioning of these ecosystems. I co-supervised NERC-funded DPhil students, Eleanor Slade (DPhil awarded November 2007) and Joe Nunez, working in Sabah (Malaysian Borneo) and in Honduras on the effects of forest management practices on the diversity of selected taxonomic groups, and the implications of variations in biodiversity for ecosystem function. My newest research programme is focused on the role of density dependent seed and seedling mortality in maintaining the diversity of tropical trees (NERC funded, in collaboration with Prof Rob Freckleton (Sheffield) and Prof Sarah Gurr (Plant Sciences, Oxford). Fieldwork for this project is based at the Las Cuevas research station in Belize, Central America, and is run by postdocs Robi Bagchi and Rachel Gallery.
(2) Insect community ecology and food web biology
Food webs involving plants, insect herbivores and their parasitoids account for the vast majority of the earth's biodiversity. Fully quantitative food webs can now be constructed which provide a robust description of community structure, and allow us to make predictions about the implications of adding or removing species from ecological communities. Increasingly, we can use these webs as a tool to better understand human impacts on ecological communities. My current work in the UK is looking at the effects of habitat fragmentation on trophic interactions using a large-scale field experiment on insect food webs in habitat fragments (NERC funded), and focusing on spatial and temporal dynamics of a specialised insect herbivore and its parasitoids on a fragmented resource (Nuffield Foundation funded). I also have an interest in the impact of climate change on trophic interactions (collaboration with Dr Rob Wilson, University of Exeter in Cornwall; plus former DPhil students Dr Chris Grobler and Dr Maartje Klapwijk). This work is addressing the question of how trophic interactions are affected as species shift their geographic distributions northwards in space (or upwards in elevation) and their phenologies forwards in time, as the climate warms. A further focus is on the community ecology and ecosystem functioning od dung beetle communities, with work in the UK led by Sarah Beynon .
Selected Recent Publications
- Bagchi, R., Swinfield, S., Gallery, R.E., Lewis, O.T., Gripenberg, S., Narayan, L., Freckleton, R.P. (2010). Testing the Janzen-Connell mechanism: pathogens cause overcompensating density dependence in a tropical tree. Ecology Letters, doi: 10.1111/j.1461-0248.2010.01520.x
- Novotny, V., Miller, S.E., Baje, L., Balagawi, S., Basset, Y., Cizek, L., Craft, K.J., Dem, F., Drew, R.A.I., Hulcr, J., Leps, J., Lewis, O.T., Pokon, R., Stewart, A.J.A., Samuelson, G.A., Weiblen, G.D. (2010). Guild-specific patterns of species richness and host specialization in plant herbivore food webs from a tropical forest. Journal of Animal Ecology, doi: 10.1111/j.1365-2656.2010.01728.x
- Staniczenko, P.P., Lewis, O.T., Jones, N.S. & Reed-Tsochas, F. (2010). Structural dynamics and robustness of food webs. Ecology Letters, 13: 891–899.
- Klapwijk, M.J., Gröbler, B.C., Ward, K., Wheeler, D. & Lewis, O.T. (2009). Influence of experimental warming and shading on host-parasitoid synchrony. Global Change Biology, 16:102-112.
- Paniagua, M.R., Medianero, E. & Lewis, O.T. (2009). Structure and vertical stratification of plant galler - parasitoid food webs in two tropical forests. Ecological Entomology, 34: 310-332.
- Lewis, O.T. (2009). Biodiversity change and ecosystem function in tropical forests. Basic and Applied Ecology, 10, 97-102.
- Tylianakis, J.M., Tscharntke, T. & Lewis, O.T. (2007) Habitat modification alters the structure of tropical host-parasitoid food webs. Nature, 445, 202-205.[Text] [Reprint]
Full List of Publications (please email me for reprints)