Access

You are not currently logged in.

Access JSTOR through your library or other institution:

login

Log in through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Separating the Effects of Litter Quality and Microenvironment on Decomposition Rates in a Patterned Peatland

Lisa R. Belyea
Oikos
Vol. 77, No. 3 (Dec., 1996), pp. 529-539
Published by: Wiley on behalf of Nordic Society Oikos
DOI: 10.2307/3545942
Stable URL: http://www.jstor.org/stable/3545942
Page Count: 11
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Separating the Effects of Litter Quality and Microenvironment on Decomposition Rates in a Patterned Peatland
Preview not available

Abstract

Decomposition rates, measured as proportion of original ash-free dry mass lost from litter bags, were studied on four microhabitats of an ombrogenous peatland in southwestern Scotland: a Racomitrium lanuginosum hummock (HR), a Sphagnum capillifolium hummock (HS), a Sphagnum papillosum lawn (L), and a Sphagnum cuspidatum hollow (H). Reciprocal transplant experiments, in which litter bags were swapped among depths both within and among microhabitat types, separated the effects of litter quality (litter type and degree of humification of the peat) and microenvironment (water table position and microhabitat type). All were important determinants of mass loss. Decomposability of the litter from different microhabitats increased in the order HR < HS < L < H. Chemical 'ageing' of the peat reduced rates of decay in highly humified peat, although a history of decay was associated with maximum decomposability of peat from HR hummocks. The suitability of hollows for decay was significantly less than for HR and HS hummocks and lawns. Peat lost mass most slowly when placed below the lowest water table, but the highest mass losses were for peat placed in, or slightly above, the zone of water table fluctuation. Mass loss decreased with depth for peat decaying in its natural position in hollows and lawns and the oxic layer of HS hummocks. A peak in mass loss occurred within the zone of water table fluctuation in HS hummocks, and just above the highest water table in HR hummocks. The results support earlier suggestions that differences due to chemical ageing of peat contribute to differences in decomposition rates between hummocks and hollows, and that hummock species are intrinsically more resistant to decay than hollow species. The pattern was complicated further, however, by the effects of water table position and microhabitat type. The combined effects of litter quality (species composition and degree of humification of the litter) and environment (microhabitat of incubation and position of incubation relative to water table) are complex, and these complexities must be incorporated into models of decomposition.

Page Thumbnails

  • Thumbnail: Page 
529
    529
  • Thumbnail: Page 
530
    530
  • Thumbnail: Page 
531
    531
  • Thumbnail: Page 
532
    532
  • Thumbnail: Page 
533
    533
  • Thumbnail: Page 
534
    534
  • Thumbnail: Page 
535
    535
  • Thumbnail: Page 
536
    536
  • Thumbnail: Page 
537
    537
  • Thumbnail: Page 
538
    538
  • Thumbnail: Page 
539
    539