Mark Hassall

Both my degrees are in Zoology and both from the University of Leeds where, for my PhD, I studied the role of soil animals in a sand dune ecosystem. This involved a range of approaches from histochemical studies of alimentary systems to population dynamics and bomb calorimetry. I moved to a Research Fellowship in the University of Wales in Cardiff where I became interested in effects of heavy metals on the soil fauna. In 1976 I moved to the School of Environmental Sciences at UEA where I set up a long term population dynamics study of both above and below ground invertebrates on Breckland grass heaths. After 30 years of sampling this forms one of the longest time series for soil animals in the world. I established that for the decomposer fauna all that is brown is not necessarily equally good to eat, rather that, as for many herbivores, competition for high quality food is very important in regulating their populations. I am interested in both plant-animal interactions, most recently tritrophic level ones involving aphids and parasitoids but also microbial-animal interactions in the soil. Not all my work is on invertebrates. I extended my analysis of the effects of three species interactions first to bean geese and then to brent geese where for the first time we illustrated the limitations of applying depletion theory to herbivores feeding in habitats where patches differ in quality as well as quantity. Currently my research group is investigating the effects of climate change, including changing rainfall patterns, on the life histories and behaviour of both soil and above ground invertebrates and on rates of carbon dioxide emissions from the soil.

Website: http://www.uea.ac.uk/env/people/perspages/hassall

The nutritive ecology of herbivores and saprophages - how do their digestive and foraging strategies affect their life histories and population dynamics, and b) predicting how global climate change may alter the behaviour and population ecology of invertebrates.

Significant Publications

• Walters R.J. and Hassall M. (2006) The temperature-size rule in ectotherms: May a general explanation exist after all? Am. Nat. 2006. Vol. 167, pp. 510–523. doi:10.1086/501029
• Walters, R.J., Hassall, M., Telfer, M.G., Hewitt, G.M. & Palutikof, J.P. (2006). Modelling dispersal of a temperate insect in a changing climate. Proc. R. Soc. B. 273: 2017-2023. doi:10.1098/rspb.2006.3542
• Hassall, M., Walters, R., Telfer, M. & Hassall, M.R.J. (2005) Why does a grasshopper have fewer, larger offspring at its range? Journal of Evolutionary Biology 19: 267-276. doi:10.1111/j.1420-9101.2005.00967.x 
• Hassall, M., Riddington, R. & Heldon, A. (2001) Foraging behaviour of brent geese, Branta b. bernicla, on grasslands: effects of sward length and nitrogen content. Oecologia 127: 97-104.doi:10.1007/s004420000563
• Lambdon, P.W. & Hassall, M. (2005) How should toxic secondary metabolites be distributed between the leaves of a fast-growing plant to minimize the impact of herbivory? Functional Ecology 19: 299-305.doi:10.1111/j.0269-8463.2005.00966.x
• Hassall, M., Heldon, A., Goldston, A. & Grant, A. (2005) Ecotypic differentiation and phenotypic plasticity in reproductive traits of Armadillidium vulgare (Isopoda: Oniscidea). Oecologia 143: 51-60.doi:10.1007/s00442-004-1772-3

Publications: EPrints Digital Repository