Performance of four mosses in a reciprocal transplant experiment: implications for peatland succession in NE China

Abstract

Sphagnum dominates the moss layer in northern peatlands, but its dominance has decreased while there has been an expansion of other moss genera in some peatlands of NE China since the 1960s. To discover the mechanisms underlying this succession, we performed a four-month reciprocal transplant experiment in Hani Peatland with three Sphagnum species, Sphagnum palustre, S. magellanicum, and S. fuscum and one other moss Polytrichum strictum. Performance of the four mosses and the environmental factors: height above water table (HWT), vascular plant cover and pH, electrical conductivity, base cations, and N and P concentrations in water in the four moss habitats were measured. Biomass production in S. palustre was negatively affected by HWT. Phosphorus had a positive effect on biomass production in S. magellanicum and Polytrichum. None of the environmental factors had any effect on S. fuscum. Overall, the three Sphagnum species deteriorated in P. strictum hummocks, while P. strictum exhibited a wider ecological amplitude and maintained or increased its vigour levels in Sphagnum hummocks. Biomass production in S. palustre and S. magellanicum was negatively affected by P. strictum indicating the competitive ability of P. strictum. Our results suggest that its wide ecological amplitude and competitive ability may explain why P. strictum can expand and replace Sphagnum in some northern peatlands.

14 kyr of atmospheric mineral dust deposition in north-eastern China: A record of palaeoclimatic and palaeoenvironmental changes in the Chinese dust source regions

“…The regional vegetation is composed of a temperate broad leaf-conifer mixed forest. The open areas of the peatland are dominated by Carex lasiocarpa and C. limosa , while the hummocks are mainly composed of Sphagnum fuscum and S. magellanicum along with Betula fructicosa and Potentilla fructicosa (Bu et al, 2013; Schröder et al, 2007).…”

A review of the effects of vehicular access roads on peatland ecohydrological processes

“…Mosses from the genus Sphagna are currently thought to form half of the world's peat (Turetsky, 2003) although it is worth noting that peat can still be produced in the absence of Sphagna (Bacon et al, 2017). Sphagnum creates acidic, nutrient poor and decay-resistant conditions which the flora develop unique adaptations to survive in (Bu et al, 2013) such as the insectivorous Drosera species. Sphagna store around 90% of their water content externally between their leaves and branches, which means variations in soil water content can have a significant impact on Sphagnum species as they have no roots and therefore are entirely reliant on passive water transport (Thompson and Waddington 2008), further demonstrating how disturbance to the hydrology might lead to significant ecosystem change.…”

“…A number of studies have recorded the recolonization of disturbed areas by species from the genus Polytrichum; this is of importance as Polytrichum species may outcompete Sphagnum mosses in some ecological conditions (Groeneveld and Rochefort, 2002;Toet et al, 2006;Benscoter, 2006;Bu et al, 2013;Bu et al, 2017). Some species are more susceptible to this competition than others (Bu et al, 2011) and this may be attributable to the stronger allelopathic effect that Polytrichum species possess when compared to Sphagnum species which can inhibit Sphagnum germination (Bu et al 2017).…”

Impacts of peat bulk density, ash deposition and rainwater chemistry on establishment of peatland mosses

“…Each driver may influence vegetation via multiple pathways; alteration of the hydrological, thermal, chemical and biological properties of peat all have the potential to impact mosses (e.g. Bu et al 2013;Lukenbach et al 2015;Price and Whitehead 2001), potentially in conflicting ways. Knowledge of which processes exert the greatest control on important peatland moss species has the potential to inform the adaptation of management tools to support ecosystem function.…”