Anthropogenic environmental change is creating new selection pressures on species' and resulting in extinction, migration and evolution within populations. The potential for evolution on ecological time scales provides opportunity for population persistence, and for stabilising ecological networks affected by biodiversity loss. On the other hand, variation in species' responses may contribute towards mismatch in ecological networks. Understanding the genetic and ecological parameters which promote or limit adaptation will improve our ability to predict species' responses to environmental change. Conservation management must focus on preserving ecological and evolutionary processes in an increasingly modified and changing UK landscape, rather than on protecting static patterns. The Wildlife Trust's 'Living Landscapes' project aims to prevent isolation and inbreeding in populations and maintain ecological interactions, improving species' ability to tolerate environmental change. In this project I explore the evolutionary potential of a key grassland plant species: the cowslip Primula veris. P. veris is an early-flowering obligate outbreeder, fully dependent on foraging insects for sexual reproduction. Through a combination of molecular genetic analysis, field observations, common garden and field experiments; phenotypic and genetic variation in P. veris populations across Wildlife Trust nature reserves is quantified and the relationship between genetic and environmental factors explored. Neutral molecular markers show that the distribution of genetic diversity is spatially variable, and the extent of isolation and differentiation varies across the landscape. Further to this, plastic responses to fine-scale differences in environmental factors are found to play an important role in determining the distribution of phenotypic variance in P. veris quantitative traits. More predictable ecological gradients across a larger spatial scale are likely to drive selection and local adaptation between sites. A complex interplay between genes and the environment is nonetheless revealed with variation in response from site to site, and trait to trait. Ecological trade-offs are predicted to be a determinant of these patterns. Finally, the impact of the observed heritable variation on plant fitness is tested in the field. This highlights the potentially buffering role that the extensive phenotypic variation observed may play, but also the potential cost of mismatch in biotic interactions. Overall, the thesis highlights that the conservation of P. veris' insect pollinators is key to maintaining healthy populations of the species and their evolutionary potential.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:682359 |
| Date | January 2016 |
| Creators | Bickler, Charlotte April |
| Publisher | University of Bristol |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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