AbstractSpecies-rich grasslands have seen a drastic decline due to agricultural intensification and abandonment and this has resulted in a fragmented distribution of grassland sites. Such grasslands are highly diverse and are being managed for conservation. Long-term studies provide valuable evidence for the effective management of grasslands and this research investigated how the vegetation of species-rich grasslands in the Forest of Bowland, NW England has changed over 25 years, a period which has seen the introduction of statutory protection measures and agrienvironment schemes. The study examined change in 35 grassland sites under contrasting management using data from two different survey methods. Results showed that overall community composition had remained stable but that change had occurred in the different management types.
More detailed investigations were carried out on 14 sites which had been managed consistently as hay meadows. The meadow community had been maintained over 25 years but there were losses and gains of important species.
To investigate whether the changes in meadow plant populations were linked to the fragmented distribution of the sites an analysis of the genetic diversity within sites and gene flow between sites was carried out. Microsatellite markers were used to study the population genetics of Rhinanthus minor (Yellow Rattle), a key meadow species. It was found that there were moderate levels of genetic diversity and evidence of gene flow between the meadows, and between the meadows and
intermediate grasslands including road verges. However, there were also local patterns of 5 differentiation. A comparison was made with samples collected from meadows in Worcestershire where there were similar levels of genetic diversity but less gene flow. These findings suggest that meadow management should be continued but should also include the wider landscape by creating or restoring other grasslands which can function as part of a network of sites.
|Date of Award||11 Jan 2018|
|Supervisor||PAUL ASHTON (Director of Studies) & MICHAEL POWELL (Supervisor)|
- long-term change
- population genetics
- Rhinanthus minor
- gene flow
Long-term change and genetic connectivity in the vegetation of mesotrophic semi-natural grasslands in the UK
SULLIVAN, E. (Author). 11 Jan 2018
Student thesis: Doctoral Thesis