Holocene Environmental History and Palaeoecology of the Lizard Peninsula, Cornwall

Garbett, Geoffrey George (2013). Holocene Environmental History and Palaeoecology of the Lizard Peninsula, Cornwall. PhD thesis The Open University.

DOI: https://doi.org/10.21954/ou.ro.0000f111

Abstract

The vegetational history and palaeoenvironments of the Lizard Peninsula are poorly understood with previous palynological research providing only fragmentary data from coastal sediments and inland palaeosols. In this study sediments from the plateau in the centre of the peninsula are analysed. This addresses questions regarding a possible preanthropogenic forest, the origins of the heathlands and the history of the endemic Erica vagans L.

Three sites were identified as having suitable pollen archives. The longest sequence has a basal ¹⁴C date of 7489±64 cal. years BP and provides firm evidence of a closed canopy birch/pine forest with hazel understory and a ground flora of ferns. There is evidence of a Mesolithic clearance phase before the rise of alder and oak at ca. 5175±125 cal. years BP. This site is 50 m below and 4 km south of the high point of the plateau on Goonhilly Downs. The sequence here has a basal ¹⁴C date of 4152±254 cal. years BP and provides evidence of Bronze Age arable farming. This ceases at ca. 3000 years BP coinciding with evidence of cooler, wetter weather. Discontinuities in the sedimentary record at both sites interrupt the landscape reconstruction.

Iron Age arable farming and heathland is indicated at the lower site at ca. 2230±82 cal. years BP with the heathland largely disappearing during the medieval period. The third site, on the edge of the Downs, indicates a predominantly heathland environment at ca. 1100 AD with some pastoral agriculture. Less than 100 years later there is unequivocal evidence of arable farming alongside heathland, and a shift from Calluna to E. vagans dominated heathland. The landscape remains stable until the 19th century when pine and later fir plantations are evidenced. Changes in the pollen assemblage in this agriculturally marginal area appear to reflect socio-political rather than climatic changes.