Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or 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.

Fate of a Wet Montane Forest During Soil Ageing in Hawaii

Kanehiro Kitayama, Edward A. G. Schuur, Donald R. Drake and Dieter Mueller-Dombois
Journal of Ecology
Vol. 85, No. 5 (Oct., 1997), pp. 669-679
DOI: 10.2307/2960537
Stable URL: http://www.jstor.org/stable/2960537
Page Count: 11
  • Read Online (Free)
  • Download ($18.00)
  • 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.
Fate of a Wet Montane Forest During Soil Ageing in Hawaii
Preview not available

Abstract

1 We chose seven sites across the Hawaiian archipelago differing only in substrate age (400 years to 4.1 × 106 years). All sites were at 1200 m elevation, and mean annual rainfall was ⩾ 4000 mm. This chronosequence reflects long-term ecosystem development from basaltic lava parent material under a humid climatic regime. 2 Live above-ground biomass of woody species ⩾ 1 m tall changed unimodally along the chronosequence from 217 tons ha-1 at the youngest site to a peak of 406 tons ha-1 at the 5000-year site, before declining to 75 tons ha-1 at the oldest site. 3 The size of the soil organic C pool above sub-surface lava or hardpan initially followed the pattern of above-ground biomass, increasing from the youngest site to the 5000-year site, and declining at the 9000-year site. However, it then steadily increased to the oldest site. The proportion of above-ground biomass C to the total C (above-ground biomass + soil) decreased linearly against logarithmic age from 74% at the youngest site to 8% at the oldest site. 4 Net soil N mineralization rate increased from the youngest site to the 5000-year site, and then declined with age to a nearly constant value except for an outstandingly high value at the oldest site. Exchangeable Ca and available P in topsoil increased from the youngest to the 5000-year site, before declining at older sites. 5 Soil redox potential (Eh7) was invariably high (⩾ c. 500 mv) at the sites ⩽ 9000 years, but declined at two old sites (410 000 years and 4100 000 years). 6 Live fine-root biomass in the topsoil increased steadily with substrate age. The distribution of fine roots in the soil profile was positively correlated with redox values. 7 High precipitation rates appear to lead to the development of iron hardpan during pedogenesis. This in turn initiates a positive feedback that promotes waterlogging and anaerobiosis, resulting in reduced organic matter mineralization and increased soil C accumulation. Reduction of biomass with age can be explained by increasingly restricted root penetration, as well as by the reduction in available soil P, N and Ca as a result of geochemical immobilization, leaching and/or reduced mineralization.

Page Thumbnails

  • Thumbnail: Page 
[669]
    [669]
  • Thumbnail: Page 
670
    670
  • Thumbnail: Page 
671
    671
  • Thumbnail: Page 
672
    672
  • Thumbnail: Page 
673
    673
  • Thumbnail: Page 
674
    674
  • Thumbnail: Page 
675
    675
  • Thumbnail: Page 
676
    676
  • Thumbnail: Page 
677
    677
  • Thumbnail: Page 
678
    678
  • Thumbnail: Page 
679
    679