Contamination of the environment by metal pollutants due to industrial practices is extremely damaging to ecosystems and hazardous to human health. Metal mining has the most significant detrimental environmental impact due to acidic, toxic metal-rich drainage from mine sites. This is particularly an issue for many of the tens of thousands of abandoned mines worldwide as many cause significant freshwater contamination. This project will determine the metal bioremediation potential of natural reed beds. Recent work in our group has shown that the improvement in water quality in a metal-contaminated river in North Wales is due to the influence of a wetland situated near the source of the river, with plant species acting as a metal sink. This project will examine the hypothesis that these plants have adapted to this metal-rich environment. It will also examine the importance of genetic diversity in developing resilience in the reed bed, and will compare a potentially genetically diverse natural reed bed with an engineered reed bed made up of single species. This research will therefore assess whether such a natural and genetically diverse wetland provides a sustainable means of remediation for metal-polluted environments. The student will gain training in a range of genetic, physiological, ecological, and geochemical techniques.

Productive forage grasslands are an important resource within UK agriculture, providing fodder for numerous livestock. Productivity in these systems is currently maintained through careful choice of seed mixture, re-seeding intervals, and potentially unsustainable practices such as fertilizer application. The economic cost of producing artificial fertilizers is rising and the carbon footprint of fertilizer production is large. The UK climate is set to become more variable and unpredictable in the coming years, with an increased occurrence of extreme events. Alternative methods of maintaining productivity of agricultural grasslands under unpredictable weather patterns, and in particular unreliable water resources, are increasingly essential for the security of our food supply in the UK, and are in crucial need of development.

Previous work has shown that increasing plant species diversity is linked to increasing productivity and stability in nutrient poor semi-natural and natural grasslands [1]. There is growing evidence that the same is true for increasing genetic diversity within plant species [2, 3]. The aim of this project is to determine if stability and productivity of forage grassland can be maintained or improved under low nutrient input and restricted water regimes by the use of species rich and genetically rich seed mixtures. We will explore the value of existing but underutilized variation within and among economic plant species to maximize output for livestock production. Traits of plants (root/shoot biomass, nutrient content, yield, productivity) grown as monocultures and mixtures under different nutrient and water regimes will be assessed using glasshouse and plot trials and the links between functional plant phenotype and individual genotype in these settings will be explored.

1. Tilman, D., D. Wedin, and J. Knops, Productivity and sustainability influenced by biodiversity in grassland ecosystems. Nature, 1996. 379(6567): p. 718-720.
2. Booth, R.E. and J.P. Grime, Effects of genetic impoverishment on plant community diversity. Journal of Ecology, 2003. 91(5): p. 721-730.
3. Reusch, T.B.H., et al., Ecosystem recovery after climatic extremes enhanced by genotypic diversity. Proceedings of the National Academy of Sciences of the United States of America, 2005. 102(8): p. 2826-2831.

The Environmental Stewardship schemes encourage the planting of pollen and nectar seed mixes within the agricultural landscape to promote healthy populations of beneficial insect species, in particular pollinators (Natural England, 2010). While this approach has been generally successful at increasing numbers of beneficial insects on farms (e.g. Blake et al. 2011), the performance of seed mixtures can be extremely variable across locations and years. Recent studies in natural systems have shown that increasing within species genetic diversity in plants can increase resilience and performance of multi-species communities (Booth & Grime 2003; Hughes et al. 2008), and determine the outcome of plant-insect interactions (Whitham 2006; Tétard-Jones 2007). This project aims to improve reliability and performance of pollinator seed mixtures by incorporating multiple varieties of a key pollinator species (red clover) and assessing plant-plant and plant-pollinator interactions. The project will involve establishing glasshouse and small plot experiments and the assessment of plant traits and pollinator visits. We will also use molecular techniques to establish population genetic structure of red clovers in commercially available and utilized mixtures. The aim is to collect data that can be used in the development of individual based network models to inform us about the emergent properties of plant-pollinator communities.

References:

• Blake, R. J., D. B. Westbury, et al. (2011). "Enhancing habitat to help the plight of the bumblebee." Pest Management Science 67(4): 377-379.
• Booth, R. E. and J. P. Grime (2003). "Effects of genetic impoverishment on plant community diversity." Journal of Ecology 91(5): 721-730.
• Hughes, A. R., B. D. Inouye, et al. (2008). "Ecological consequences of genetic diversity." Ecology Letters 11(6): 609-623.
• Natural England (2010) Entry Level Stewardship - Environmental Stewardship Handbook (Third Edition – February 2010)
• Tétard-Jones, C., M. A. Kertesz, et al. (2007). "Genotype-by-genotype interactions modified by a third species in a plant-insect system." American Naturalist 170(3): 492-499.
• Whitham, T. G., J. K. Bailey, et al. (2006). "A framework for community and ecosystem genetics: from genes to ecosystems." Nature Reviews Genetics 7(7): 510-523.

Forest ecosystems are particularly important for the provision of numerous ecosystem services such as carbon sequestration, pollinators, water catchment, medicinal plants and food. Forest ecosystems with high genetic diversity are expected to be more productive in providing ecosystem services. This project will study forest ecosystems in northeast India, a region of the world, which although it still has substantial forests, is experiencing severe deforestation. In this pilot project the student will develop a method to quantify the provision of some ecosystem services from NE Indian forests. The project also involves the estimation of genetic diversity using microsatellites from taxa at different tropic levels (e.g. insects and felids) from NE India forest fragments to determine if genetic diversity is correlated among species and how genetic diversity relates to forest fragment size, connectivity and long term stability. In the long term, this will enable us to determine if forest ecosystems with high genetic diversity have greater ecosystem productivity.

The aim of the MPhil project is to:

1. Develop a system to measure ecosystem services e.g. how much meat can be harvested from a given area? How many medicinal plants?
2. Test the underlying hypothesis that the genetic diversity of different taxa are correlated and depend both on long term stability and recent disturbance. This will use two taxa from lower and higher tropic levels: 1. highly forest dependent mosquito species that form part of a lower trophic level and the highest trophic level e.g. clouded leopard or other cats. For the former taxon, collections are already available throughout NE India and for the latter, samples will be collected in this project with team established in India. Microsatellites are already available for both taxa. Detailed information is available on the effects of forests on long term environmental stability from both previous work and our ongoing project on mosquitoes in Northeast India.

The idea that genetic variation within a tree species may influence associated communities of epiphytes and invertebrates is well established. Citrus groves provide a productive forest system where varieties are often clearly defined and can be an important source of associated biodiversity in an agricultural landscape. The aim of this project is to determine the association between tree genetic diversity, associated epiphyte and arthropod diversity (pest, biocontrol and commensal species), and tree productivity. The work will be carried out in tropical (orange/grapefruit) groves in Belize. The project will be supervised jointly by Dr Jennifer Rowntree and Dr Richard Preziosi.

Ecological adaptation can be defined as the entirety of molecular and cellular changes that allow an organism to survive and reproduce better in his environment. For example the ability of some yeast species to grow rapidly when the nutrients are scarce or when the temperature is low represent part of their ecological adaptation to those environments.

Using large scale experimental techniques, we identified genes in S. cerevisiae laboratory strain that may be fundamental to cold adaptation. In particular we run competition experiments at low temperature (16°C) and in different nutritional media using the hemizygote yeast deletion collection, encompassing 6,000 different mutant strains. With such approach we were able and study the relationship between mutations and environmental changes and to predict candidate genes essential for the growth at low temperature.

In the attempt to extrapolate the laboratory setting towards natural systems, the aim of this MPhil project is to validate the lab-based predictions in two ecological sympatric species adapted to grow optimally at different temperatures, namely S. kudriazvevii, a natural cryotolerant yeast, and the wild isolates S. cerevisiae 96.2, adapted to grow at warmer temperatures (30°C). The student will create gene knock-outs of candidate genes in both natural species and study the phenotypes and fitness of the engineered strains under different nutritional limitations and temperatures.

Related Publications

1. Delneri D., Hoyle D.C., Gkargkas K., Cross E.J.M., Rash B., Zeef L., Leong H.-S., Davey H., Hayes A., Kell D.B., Griffith G.W., and Oliver S.G. (2008). Identification and characterisation of high flux control (HFC) genes of Saccharomyces cerevisiae through competition analyses in continuous cultures. Nature Genetics, 40: 113-117.
2. Holland S., Lodwig L., Sideri T., Reader T., Gkargkas K., Clarke I., Hoyle D. C., Delneri D., Oliver S.G., and Avery S. (2007) Application of the heterozygous yeast strain collection to elucidate the basis of chromium toxicity, Genome Biology, 8 (12): R268.
3. Harrison R., Papp B., Pal C., Oliver S.G. and Delneri D. (2007) Plasticity of genetic interactions in metabolic networks of yeast, Proc Natl Acad Sci U S A. 104: 2307-2312.

Dominant species such as sponges in tropical marine lagoons have a signifiant influence on associated biodiversity and potentially contribute to storm damage and shoreline protection. This project will collaborate with ongoing sponge restoration projects off the coast of Florida to determine 1) the effect of species and genetic variation in sponge communities on associated invertebrate biodiversity and 2) the effect of genetic variation in dominant sponges on resilience to storm damage. Applicants should have some ability in snorkeling or diving and must be willing to work in marine environments. This project will be run in association with the University of Florida and Old Dominion University.

Street trees provide several ecosystem services in cities. They cool the city down, reducing the urban heart island effect by evapotranspiring and reflecting more sunlight; they cool people down by shading them; and they reduce flash flooding by intercepting rain and diverting runoff to their roots (Ennos, 2010). However, our recent research has found that their effectiveness depends both on the growing conditions (Rahman et al, 2011) and the species chosen. Species with a denser crown and growing in less compacted soil grow faster and provide more cooling. Another possible source of variability comes from within species genetic diversity. Since most street trees are grown in monocultures in large tree nurseries, and from limited seed provenance, it is possible that street trees will lack genetic diversity and this can lead them to be vulnerable to pests and diseases.

This project will investigate the environmental performance of street trees in Greater Manchester and at a major tree nursery and relate it to their genetic diversity. Research will focus in particular on the common street tree Pyrus calleryana, using trees planted in recent years by the Red Rose Forest and tree health and performance will be investigated when trees are both grown on their own and in larger blocks. The relative effect of growing conditions and genetic diversity will then be compared. The results should provide recommendations to growers and landscape architects about how to grow and choose street trees.

References

• Ennos, A.R. (2010). Urban cool. Physics World 23 (8), 22-25.
• Rahman, M.A., Smith, J.G., Stringer, P. and Ennos, A.R. (2011). Effect of rooting conditions on the growth and cooling ability of Pyrus calleryana. Urban Forestry and Urban Greening. 10, 185-192.

Amphibians are an important component of forest ecosystems and are often keystone species that underpin ecosystem functioning. For example, plethodontid salamanders and Craugastor and Eleutherodactylus frogs have been shown to be important in reducing carbon release into the atmosphere from leaf litter and preferentially return carbon into the forest ecosystem. Where they are numerous, amphibians are likely to play an important role in providing this important, but undervalued, ecosystem service. This MPhil project will ask the question: Are amphibians more numerous when their populations have greater genetic diversity? The student will conduct field surveys and use sequence data to assess the abundance and genetic diversity of several populations of amphibians in Central America.