The fungus Hypocreopsis rhododendri forms orange-brown, distinctively lobed stromata on the stems of trees and shrubs. It is found both in Corylus avellana (hazel) scrub on the western fringe of Europe, and on understory shrubs in the Appalachian woodlands of eastern North America. On the basis of its narrow distribution and perceived threats to its Atlantic hazel habitat, H. rhododendri has been prioritised for conservation action in Scotland. A lack of knowledge regarding the species' ecology, however, presents a significant obstacle to effective conservation action. This thesis reports on investigations into the ecology of H. rhododendri, with the aim of providing a scientific basis upon which decisions regarding the species' conservation may be taken. The research yielded the following key findings: Investigations into the population genetics of the fungus provided evidence of a genetic bottleneck in H. rhododendri's European population, and hinted at fairly recent gene flow between the species' European and North American populations. On this basis it is hypothesised that H. rhododendri established in Europe recently, following dispersal from North America. Research into the genetic constitution of H. rhododendri's stromata, the distribution of its mycelia in stems and its ability to degrade wood in vitro provided strong support for the hypothesis that H. rhododendri is a superficial parasite of the wood decay fungus Pseudochaete corrugata. Field surveying revealed that H. rhododendri has a fairly high rate of population turnover, with stromata typically surviving for less than two years. It also revealed that the species' distribution is not strongly influenced by the structure and exposure of its scrub habitat. In view of the above findings and the fact that conservation action is already being undertaken to conserve the species' Atlantic hazel habitat, it is not recommended that conservation action specifically targeted at H. rhododendri is carried out in Scotland.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:629389 |
| Date | January 2014 |
| Creators | Grundy, Katherine C. |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=214826 |
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