Late Holocene regime shifts in moorland ecosystems: high resolution data from the Pennines, UK

Abstract

Abstract:Identifying critical shifts in ecosystems caused by human impacts has become a priority for understanding resilience to change and setting realistic management goals. Previous work suggests that many British blanket peats have suffered a loss of functional integrity over recent centuries, but it is unclear whether all moorland habitats are equally vulnerable. This study examines the relative sensitivity of four contrasting moorland communities to historic land-use changes and assesses whether these management pressures are pushing some moorlands beyond their Holocene range of variability. Late Holocene dynamics in the Peak District, northern England, were investigated using high-resolution pollen, fungal spore and charcoal data, and multivariate analyses. All sites show high Calluna values during the nineteenth century and converge on local Poaceae-dominance during the twentieth century. This involved a shift from gradual or cyclical variability and moderate changes in pollen abundance during preceding centuries, to rapid transitions between mono-dominant pollen assemblages and a functional shift to taxa with competitive traits; these are interpreted as a regime shift. Evidence for the recent recovery of dwarf-shrubs and Sphagnum is strong at one site, with slight evidence from two others, but disturbance could push the system back to grass-dominance. The deep blanket peat site may have crossed a threshold, leading to a persistent grass-dominated state. Studying regime shifts on decadal to centennial scales can help bridge the gap between ecology and palaeoecology by providing a robust basis for assessing vulnerability, setting restoration priorities and managing novel peatland states.Response to Reviewers: Revisions made to this submission:Updated Bennett reference -with current School name (the pollen catalogue gives the older Archaeology and Palaeoecology departmental name)Attached all figures in EPS format.Checked image resolution in Online resource 1: sufficient for viewing at >100% size. I have uploaded an amended file without 'track changes' which were inadvertently left in revision r2. Powered by Editorial Manager® and ProduXion Manager® from Aries Systems CorporationAccepted minor text amendments Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation ABSTRACTIdentifying critical shifts in ecosystems caused by human impacts has become a priority for understanding resilience to change and setting realistic management goals. Previous work suggests that many British blanket peats have suffered a loss of functional integrity over recent centuries, but it is unclear whether all moorland habitats are equally vulnerable. This study examines the relative sensitivity of four contrasting moorland communities to historic land-use changes and assesses whether these management pressures are pushing some moorlands beyond their Holocene range of variability. Late Holocene dynamics in the Peak District, northern England, were investigated using high-resolution pollen, fungal spore ...

Quantified moorland vegetation and assessment of the role of burning over the past five millennia

“…Archaeological evidence for grazing (field systems, enclosures) extends back to at least 4,000 years BP on Exmoor (Riley & Wilson‐North, ), and grazing intensity is likely to have varied both spatially and temporally. Coprophilous fungi can be used as indicators of grazing (Cugny, Mazier, & Galop, ), and Davies () has utilized this approach in the Pennines (UK) to assess the role of grazing animals in recent moorland vegetation dynamics, finding associations between coprophilous fungi, contraction of heather and increases in Poaceae (pollen percentage‐based) over recent centuries. The application of dung fungal spores on Exmoor is an avenue of research with high potential for further elucidating moorland vegetation–grazer interactions, and high‐resolution coprophilous dung fungal records are in progress (Ombashi unpubl.).…”

“…Within this study the limitations of the original age–depth models (age uncertainty of each sample) and the temporal sampling resolution (years between adjacent samples) necessitated a 500‐year time window. Moorland vegetation changes can occur on considerably shorter time scales, for example Davies () details regime shifts from Calluna dominance to Poaceae dominance in the Pennines (UK) over periods of time as short as 25–85 years. Where higher‐resolution sampling and age–depth models supported by more radiocarbon dates or other time markers are available it may be possible to apply the LRA to shorter time windows (Fredh et al., ).…”

“…The LRA‐based approach does not replace the highly detailed, high temporal resolution work from individual sites such as that of Chambers et al. () and Davies (). This is essential in exploring burning/vegetation relationships, and future and on‐going research on Exmoor and other uplands, which couples high‐resolution pollen analyses with proxies for grazing such as coprophilous fungi will provide powerful, conservation management‐oriented insights.…”

“…(Cugny, Mazier, & Galop, 2010), and Davies (2016) Where higher-resolution sampling and age-depth models supported by more radiocarbon dates or other time markers are available it may be possible to apply the LRA to shorter time windows (Fredh et al, 2012). The LRA-based approach does not replace the highly detailed, high temporal resolution work from individual sites such as that of Chambers et al (2007) and Davies (2016). This is essential in exploring burning/vegetation relationships, and future and on-going research on Exmoor and other uplands, which couples FYFE Et al.…”

Using palaeoecology to advise peatland conservation: An example from West Arkengarthdale, Yorkshire, UK

“…(Chambers, Mauquoy, Cloutman, Daniell, & Jones, 2007;Chambers, Mauquoy, Gent et al, 2007), Scotland (Davies & Watson, 2007), Northern England (Chambers & Daniell, 2011) and the Pennines (Davies, 2015), with encouraging results. More recently, three further studies have been conducted in Yorkshire at Keighley Moor, by Blundell and Holden (2015); at Mossdale Moor, by McCarroll, Chambers, Webb, and Thom (2015); and at Oxenhope Moor by McCarroll (2015).…”