A 9600‐year record of water table depth, vegetation and fire inferred from a raised peat bog, Prince Edward Island, Canadian Maritimes

Abstract

A 582‐cm‐long peat core was collected from Baltic Bog, an ombrotrophic peatland in north‐eastern Prince Edward Island, Canada. The core was studied for testate amoebae, plant macrofossils, macrocharcoal, peat humification and organic matter content. The results show that Baltic Bog first developed ∼9600 cal a BP as a minerotrophic peatland (fen) dominated by Cyperaceae. At 8200 cal a BP, the fen transitioned into a peat bog dominated by Sphagnum. Between 8200 and 4000 cal a BP, water table depth (WTD) was generally low and the bog surface supported trees such as Picea mariana. From 4000 to 1700 cal a BP, WTD rose and the bog became more open. The macrocharcoal results show that the period ∼2000–1000 cal a BP was characterized by several fire events that may have occurred on the bog surface at the core site. The results presented in this paper correspond closely with previous fossil pollen research done at Baltic Bog and suggest that regional climate change was a key factor in controlling long‐term WTD variability and vegetation change at the site.

Holocene vegetation dynamics and hydrological variability in forested peatlands of the Clay Belt, eastern Canada, reconstructed using a palaeoecological approach

“…Over the last decade, many studies in boreal peatlands of eastern Canada have combined macrofossils and testate amoeba data to reconstruct ecohydrological dynamics in relation to climate and fire over millennial time scales (e.g. Loisel & Garneau 2010;van Bellen et al 2011van Bellen et al , 2013Peros et al 2016;Garneau et al 2017). All these studies focussed on open non-forested peatlands and to our knowledge, such multi-proxy palaeoecological reconstructions have never been conducted in forested peatlands.…”

The signal of climate changes over the last two millennia in the Gulf of St. Lawrence, eastern Canada

“…200 cal yr BP, which suggests wetter and/or cooler conditions. In northeastern Prince Edward Island, higher water-table depths are reconstructed from 550 to 150 cal yr BP using testate amoeba records from Baltic Bog, which also suggest wetter conditions (Peros et al, 2016). According to our data, the LIA was a cold period not necessarily marked by enhanced precipitation, as reconstructed SSS suggests lower freshwater discharge to the GSL.…”

“…However, none of the abovementioned records provide a temporal resolution suitable to resolve centennial to decadal variability of hydrographical conditions. In terrestrial areas surrounding the GSL, pollen, spores, and testate amoebae preserved in peat bogs and lake sediments show changes in the vegetation coupled with large variations in water table depth (e.g., McCarthy et al, 1995; Hughes et al, 2006; Magnan and Garneau, 2014; Peros et al, 2016; Sauvé, 2016; Fig. 1), suggesting climate variations accompanied with changes in precipitation regimes.…”

An 8000-year multi-proxy peat-based palaeoclimate record from Newfoundland: Evidence of coherent changes in bog surface wetness and ocean circulation

“…However, few investigations on the North Western Atlantic seaboard exist (Hughes et al, 2006;Mackay, 2016;Daley et al, 2016;Peros et al, 2016) despite the widespread occurrence of near-pristine peatlands. Peatlands are abundant in Newfoundland covering 18% (20,000 km 2 ) of the land area (Wells and Pollet 1983), the oldest forming after the Newfoundland Ice Sheet retreated c. 9-10 ka (Dyke and Prest, 1987).…”

“…Although most early peatland palaeoclimate research was carried out in Northwest Europe, studies are now global (Nichols and Huang, 2012; Novenko et al, 2015). However, few investigations on the North Western Atlantic seaboard exist (Daley et al, 2016; Hughes et al, 2006; Mackay et al, 2016; Peros et al, 2016) despite the widespread occurrence of near-pristine peatlands. Peatlands are abundant in Newfoundland covering 18% (20,000 km 2 ) of the land area (Wells and Pollett, 1983), the oldest forming after the Newfoundland Ice Sheet retreated at c. 9–10 ka (Dyke and Prest, 1987).…”