Peatland vegetation change and establishment of re-introduced Sphagnum moss after prescribed burning

Alice Noble,Sheila M Palmer,Alistair Crowle,David J Glaves,Joseph Holden

doi:10.1007/s10531-019-01703-0

Alice Noble, Sheila M Palmer + Show 3 more

Open Access

https://doi.org/10.1007/s10531-019-01703-0

Copy DOI

Journal: Biodiversity & Conservation	Publication Date: Feb 8, 2019
Citations: 12	License type: open-access

Affiliation: University of Leeds, Natural England

Abstract

Fire, including prescribed burning, is common on peatlands globally and can affect vegetation, including peat-forming Sphagnum mosses, and affect ecosystem services. We monitored vegetation in different burn-age categories at three UK peatland sites over a 19-month period. Half of the plots had Sphagnum fragments added and their survival was assessed. Changes in vegetation composition over time, and associations between vegetation composition, site and burn-age category were investigated. Plots in the most recently burned category were likely to have more bare peat, a thinner moss layer and lower vascular plant strata. Graminoid cover initially increased after burning but was low after 10 + years. Dwarf shrub cover increased after burning and remained high after 10 + years. At the most Sphagnum-rich site, a high proportion of existing Sphagnum cover was bleached one year after burning, but recovery occurred during the study period. Sphagnum re-introduction success decreased over the study period in the most recent and intermediate burn-age categories at the most Sphagnum-poor site. These results show that burning rotation length is an important factor in determining site-level vegetation composition on burned sites. More frequent burning will result in a greater proportion of land in the early post-burning stages, potentially resulting in a thinner moss layer, more bare peat and less healthy Sphagnum, with potential consequences for carbon balance. No evidence was found to support the use of burning as a tool to increase existing Sphagnum or promote Sphagnum re-establishment success.

Highlights

Peatlands are important carbon stores (Yu et al 2010), covering around 423 million ha globally (Xu et al 2018)
All three sites were managed for grouse shooting and had been burned on a rotational basis regularly for at least several decades. Their vegetation principally consisted of dwarf shrubs, graminoids and mosses, which occur in varying quantities at each site (Table 1)
The Non-metric Multidimensional Scaling (NMDS) ordination results (Stress = 0.184, K = 2) suggest that vegetation communities differed according to both site and burn-age category

Summary

Introduction

Peatlands are important carbon stores (Yu et al 2010), covering around 423 million ha globally (Xu et al 2018). Vascular plants including graminoids and dwarf shrubs contribute to the structural diversity of peatland habitats (Malmer et al 1994) and can provide food and shelter for livestock and wildlife (Garnett et al 2000; Robertson et al 2017; Thompson et al 1995). Some graminoid species, such as the sedge Eriophorum vaginatum, can contribute to peat formation (Kalnina et al 2015; McClymont et al 2011). Dominance of some vascular plants, such as Calluna vulgaris, may increase the amount of carbon lost as dissolved organic carbon (DOC) and CO2, potentially owing to their impact on water table and soil temperature (Armstrong et al 2012; Dixon et al 2015)

Objectives

Methods

Results

Discussion

Conclusion