The high floristic biodiversity value of ancient woodland is widely acknowledged, as is its status as a fragmented habitat of limited spatial extent. The distinctive vegetation of ancient woodland is an important factor in its conservation. Specifically, Ancient Woodland Indicator (AWI) species have been shown to be poor dispersers and incompatible with a fragmented habitat that is subject to environmental change. In recognition of their ecological importance, both Ancient Semi-Natural Woodland (ASNW) and Ancient Replanted Woodland (ARW) are protected by legislation. This thesis took the novel approach of examining the distinctiveness and community ecology of vegetation communities in all three woodland types of ASNW, ARW, and recent woodland. Importantly, analyses were based on new high-granularity primary vegetation and soil data. To address questions raised in the literature regarding the accuracy of ancient woodland and AWI identification, this research examined the metrics used to distinguish these habitats and species. Increasingly, the literature calls for further understanding of the ecological drivers of ancient woodland vegetation distinctiveness. In response, this research tested for differences in species composition of canopy, shrub, herb layer, AWI, and moss communities across all three woodland types. For AWI species, biotic, abiotic, and biogeographical variables were analysed for their contribution to community distinctiveness. Results highlighted the importance of consistency in metric selection when assessing the distinctiveness of ancient woodland and determining indicator species. In addition to the usual alpha scale measure of distinctiveness, assessing richness and community composition at the beta and gamma scales is recommended to inform conservation. Life traits and dispersal mechanisms were important differentiators for herb layer community composition among the woodland types. AWI richness was equally strongly explained by biogeographical variables as by ASNW, ARW, and recent status. Overall, this thesis supported ecological and biogeographical explanations for the distinctiveness of ancient woodland vegetation.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:754436 |
| Date | January 2018 |
| Creators | Swallow, Kelly A. |
| Contributors | Goodenough, Anne ; Wood, Matt |
| Publisher | University of Gloucestershire |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://eprints.glos.ac.uk/5800/ |
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