Potential Dissertation Projects

Available With John Warren

Does asymmetry in leaves act as an indicator of plant 'stress' and therefore have potential as a tool for predicting conservation needs?

Populations of rare plants can be stable or in decline, perhaps asymmetry can be used as a measure of stress and predictor of population decline without the need for extensive population monitoring.

Black-Samuelsson,S. and Andersson,B. (2003) The effect of nutrient stress on developmental instability of Acer platanoides and Betula pendula. American Journal of Botany. 80: 1107-1113.

Has movement been overlooked as a mechanism to attract pollinators / deter herbivores? Do wavy flowers attract more pollinators than non-wavy flowers. (fun one this lots of simple experiments can be done which involve sitting in the sun watching bees!)

Also does floral waving deter floral herbivory? ie do daffodils with longer stalks get less damaged by slugs than those with shorter stalks

Warren, J. and James, P. (2008) Do flowers wave to attract pollinators? A case study with Silene maritima. Journal of Evolutionary Biology, 21: 1024-1029.

New Hedges vs. Old.

Do new hedges and old hedges differ in their conservation value in terms of numbers of flowers and in flowering times, OR numbers/biomass of berries, and in times of berry availability? And thus what can be done to enhance the conservation value of new hedges?

Pollard, E., Hooper, M.D. & Moore, N.W. (1974) Hedges. The New Naturalist. Collins, London.

Pierce,J. and Warren,J. (2004) A comparison of the nectar resource of new and old hedges and its implications for farmland biodiversity. Submitted to Biological Agriculture and Horticulture.

Competing Berries .

Do berries compete to attract birds? Berries ripen at different times, so birds have food available throughout the winter. But is competition driving this phenology?

See papers by Burns K.C.

Hedge Diversity.

Do botanically diverse hedges support more invertebrate species or more birds?

Do hedges, which contain more woody species, also have more diverse ground flora than do species of poor hedges?   

Maudsley MJ (2000) A review of the ecology and conservation of invertebrates in Britain Journal of Environmental Management. 60: 65-76.

There are lots of potential projects which involve opportunities for sitting in the sun watching pollinators visiting plastic flowers. The research questions being community ecology related - is community structure limited by the availability of pollination niches (why are there no blue flowered species in MG7 grasslands, or evolutionary questions about the origins of diversity.

Warren, J., and Mackenzie S. (2001) Why are all colour combinations not equally represented as flower-colour polymorphism? New Phytologist, 151: 237-241.

Warren, J. and Billington, T. (2005) Flower colour phenology in British mesotrophic grassland communities. Grass and Forage Science, 60: 332-336.

Petal number is more variable in the creeping buttercup than the meadow buttercup. This appears to be related to its long-lived vegetative lifestyle. But what are the consequences of this? Is petal number trade-off against seed number, does living longer mean - better sex, ie do more petals attract more pollinators and result in more outbreeding?

Warren, J. (2009) Extra petals in the buttercup (Ranunculus repens L.) provide a quick method to estimate the age of meadows. Annals of Botany, 104: 785-788.

Warren,J., and Diaz,A. (2001) A two pollinator model for the evolution of floral complexity. Evolutionary Ecology, 15: 157-166.

What maintains the very common colour polymorphism in red valerian?

Why do most populations around Aberystwyth seem to be entirely pink (heterozygous) individuals - what happens to the white and red homozygotes?

There are lots of research projects that can be carried out using computer vegetation models. These can address questions about ecology theory or more practical ones about the impact of management on diversity.

Local Provenance.

Does seed provenance affect the establishment of wild flowers? Conservationists worry about the use of non-local seeds in habitat restoration for several reasons, one being that they may be less well adapted to local conditions. This can be tested in a dissertation project by looking at the establishment rates of seed from several origins.

Jones AT and Hayes MJ (1999) Increasing floristic diversity in grassland: the effects of management regime and provenance on species introduction. Biological Conservation. 87: 381-390

Alien genes.

Ecological effects resulting from the spread of alien genes. Established plots of native, cultivated hybrid and North American gooseberries are available to study the impact of alien genotypes on invertebrate herbivores.

Introduced tree species are considered to support fewer invertebrate species than do natives trees. But is this a statistical artefact of their restricted range and unfair comparisons which should be restricted to within genus? This can be investigated by observations of biodiversity associated with native and non-native trees within genus.

Manchester SJ, Bullock JM  (2000) The impact of non-native species on UK biodiversity and the effectiveness of control. Journal of Applied Ecology. 37: 845-864.

Do slugs selectively graze garden plants more than their wild relatives? This question has implications for wildlife & organic gardening. It may be that breeders by selecting for horticultural varieties have reduced the levels of defence chemicals found in wild plants.

Buschmann H, Edwards PJ, Dietz H. (2005) Variation in growth patterns and response to slug damage among native and invasive provenances of four perennial Brassicaceae species.  Journal of Ecology. 93: 322-334.

If seeds wash down stream rather than up - then mapping morphological traits in Himalayan Balsam should show more variation in down stream populations than those upstream. This would have implications for the management of alien invasive species.

What about using ecological techniques such as capture re-capture to assess the population of MacDonald derived rubbish along the local roads. GIS could also used to map its location and movement and relate this to road class

Hybrid plants typically have low fertility, producing very few seeds. But how viable are these seeds? Are they fitter because there are few of them, and less prone to predation, or less fit because dispersal mechanisms fail to work? The answers to the questions are very important in understanding the evolution of new and invasive species.