The ecology of upland ponds in mid-Wales

Bransden, Anna Lucy 2011. The ecology of upland ponds in mid-Wales. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

Ponds are diverse habitats that make major contributions to regional biodiversity, yet have received relatively little attention compared to other freshwater environments. This study investigated the physico-chemical characteristics and ecology of a nationally important concentration of temporary upland ponds in Radnorshire, Wales in both spatial and temporal dimensions (up to 80 ponds over 18 months). Plant and macroinvertebrate communities were typical of oligotrophic, acidic ponds and appeared to vary along gradients of pH and hydroperiod, whilst including several nationally rare/threatened taxa. A national classification based on the biological community of temporary ponds grouped Radnorshire ponds with a few others in western Britain. Ponds were generally small, shallow and acidic with low concentrations of nutrients and dissolved minerals. Water chemistry was associated with concentration by evaporation and dilution by rainwater, whilst the overall hydrology of ponds was successfully modelled using local meteorological data. Over the course of the study, large increases in macroinvertebrate abundance were observed, but assemblage composition and richness were broadly constant. Seasonality in the abundance of individual macroinvertebrate taxa was evident and suggested that autumn was the optimum time for invertebrate sampling in terms of abundance and diversity. Nearly 40% of the variation among ponds in macroinvertebrate and plant communities was explained by a combination of a species-area effect and differences in pH: no effect of pond isolation was detected within the context of the study region. A cumulative species-area analysis found that a group of small ponds support higher biodiversity than a single large pond of the same area, highlighting the importance of considering beta diversity. Taken together, the findings of this PhD project justify the designation of Radnorshire as an Important Area for Ponds: the ponds form a distinct ‘pondscape’ of >80 waterbodies, with a highly dynamic environment and biota, and which provide a major habitat resource for rare species in the UK.

Item Type:	Thesis (PhD)
Status:	Unpublished
Schools:	Biosciences
Subjects:	Q Science > QH Natural history > QH301 Biology Q Science > QK Botany
Uncontrolled Keywords:	Pond, Upland, Wales, Macroinvertebrate, Macrophyte
Date of First Compliant Deposit:	30 March 2016
Last Modified:	09 Jan 2018 21:47
URI:	https://orca.cardiff.ac.uk/id/eprint/26702

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