I am a community ecologist and conservation biologist. My interest is in the processes that maintain, structure and threaten biodiversity, particularly in highly diverse tropical forest ecosystems. My current research areas include the impact of human activities (including fragmentation and commercial timber extraction) on the diversity and functioning of tropical forest ecosystems; the structure and dynamics of food webs involving plants, insect herbivores and their parasitoids; the role of plant pathogens and insect herbivores in structuring and maintaining the high diversity of tropical plants; and the impact of climate change, habitat fragmentation and degradation on interspecific interactions and associated ecosystem functions and services.

Bagchi, R., Gallery, R.E., Gripenberg, S., Gurr, S.J., Narayan, L., Addis, C.E., Freckleton, R.P. & Lewis, O.T. (2014) Pathogens and insect herbivores drive rainforest plant diversity and composition. Nature, 506, 85-88. Morris, R.J., Gripenberg, S., Lewis, O.T. & Roslin, T. (2014). Antagonistic interaction networks are structured independently of latitude and host guild. Ecology Letters 17, 340-349. Beynon, S.A., Slade, E.M., Mann D.J. & Lewis, O.T. (2012). Species-rich dung beetle communities buffer ecosystem services in perturbed agro-ecosystems. Journal of Applied Ecology 49, 1365–1372. Bagchi, R., T. Swinfield, R. E. Gallery, O. T. Lewis, S. Gripenberg, L. Narayan,and R. P. Freckleton (2010). Testing the mechanism of the Janzen-Connell effect: pathogens cause over-compensating density dependence in seedlings of a tropical tree. Ecology Letters 13, 1262-1269. 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. Tylianakis, J.M., Tscharntke, T. & Lewis, O.T. (2007) Habitat modification alters the structure of tropical host-parasitoid food webs. Nature, 445, 202-205