Decomposition along a bog to rich fen gradient in central Alberta, Canada

Abstract

The carbon (C) and nitrogen (N) contents and decomposition rates of the aboveground litter were measured in five peatlands (bog, poor fen, open moderately rich fen, wooded moderately rich fen, and lacustrine sedge fen) in central Alberta, Canada, over a period of 2 years. Decay rates and C and N content of the dominant species were measured at each site. Weight losses after 1 and 2 years were negatively correlated with initial and final C/N ratios. Weight losses were positively correlated with initial and final %N, with the fastest weight losses in the species with the highest N content. Rates of decay within sites differed according to litter types, with Carex > Betula > mosses. Decay rates and C and N content were also determined for a standard litter type (Carex lasiocarpa), to make cross-site comparisons. Standard litter weight losses differed between sites after 1 and 2 years of decay. The sites ranked poor fen > wooded–rich fen > bog > open–rich fen > sedge fen in order of greatest to smallest percent weight loss after 2 years. After 1 year, weight loss of the standard litter was negatively correlated with water level and pH-related parameters and positively correlated with total dissolved P. Decomposition was correlated with both substrate quality and environmental parameters, but the former may be more important than the latter in controlling decomposition in these peatlands. Keywords: decomposition, peatlands, carbon, nitrogen, hydrology, water chemistry.

Impact of Simulated Changes in Water Table Depth on Ex Situ Decomposition of Leaf Litter from a Neotropical Peatland

“…2) was comparable in magnitude to the impact of reduced water tables on in situ litter decomposition in south east Asia (Brady 1984) and boreal and temperate wetlands (Szumigalski and Bayley 1996;Haraguchi et al 2003;Williams and Yavitt 2003). The clear effect of the flooding treatment on ex situ mass loss rates suggests that litter decomposition at these sites may be highly sensitive to even small decreases in the height of the water table, which has important implications for the contribution of litter to long term C accumulation in tropical peatlands.…”

Plant Litter Decomposition and Nutrient Release in Peatlands

“…Decomposition of Sphagnum litter has been demonstrated to be enhanced, at least after 1 year of field burial, by low initial values of phenolics/nutrient and C/nutrient quotients [Szumigalski and Bayley, 1996;Limpens and Berendse, 2003;Dorrepaal et al, 2005;. On the basis of selected data, we observed that k values of Sphagnum litter were negatively correlated with initial AUR/N quotients (Pearson's r = -0.66; p < 0.05; n = 11; Figure 4).…”

Scots pine litter decomposition along drainage succession and soil nutrient gradients in peatland forests, and the effects of inter-annual weather variation

“…Most of the variation in decomposition rates can be explained by litter quality, temperature and soil moisture (Berg et al, 1993;Walse et al, 1998). In pristine (undrained) peatlands, decomposition of similar litter materials is related not only to water level (e.g., Santelmann, 1992) but also to soil and/or soil water pH and base cation content (Verhoeven and Toth, 1995;Verhoeven et al, 1996;Szumigalski and Bayley, 1996) being generally faster in fens than bogs (Farrish and Grigal, 1988;Verhoeven et al, 1990). After permanent water level drawdown, these characteristics gradually change (Laine et al, 1995ab;Laiho et al, 1999).…”