University of Tasmania
Browse

File(s) under permanent embargo

Diurnal to decadal changes in the balance between vegetation and bare ground in Tasmanian fjaeldmark

journal contribution
posted on 2023-05-19, 09:48 authored by Annandale, B, James KirkpatrickJames Kirkpatrick
Periglacial processes are active under current climatic conditions on the more exposed peaks and ridges of Tasmania’s high country. Non-sorted steps, stripes, and solifluction lobes with vegetated risers and bare treads have formed on many of the mountains capped in fissile sedimentary rocks. Any disturbance to the balance between vegetation and bare ground can result in biogeomorphic feedbacks leading to an increase or decrease in periglacial activity and thereby threaten the survival of fjaeldmark. We tested the hypotheses that vegetation helps create risers by capturing material moved by needle ice, water, and wind, and that the balance between vegetation and bare ground in fjaeldmark is dynamic in Tasmania at the decadal time scale. Repeat photo plots and temperature data loggers were employed to monitor the dynamism of two non-sorted lobes on Mount Rufus over a seven-month period. Diurnal freeze/thaw cycles resulted in needle ice formation on the bare treads and promoted downslope movement of the surface layer through frost creep. Vegetation was observed to reduce geomorphic activity and to capture soil and clasts transported downslope, thereby steepening the risers. Aerial photographic analysis showed a 0.065% per annum increase in vegetation cover in fjaeldmark since the mid-20th century. Mountains that had a high number of days with snow cover were especially prone to increases in vegetation cover. Decline in vegetation cover occurred on some mountains burned during the past century. The smallest changes occurred on the most exposed peaks and ridges.

History

Publication title

Arctic, Antarctic and Alpine Research

Volume

49

Pagination

473-486

ISSN

1523-0430

Department/School

School of Geography, Planning and Spatial Sciences

Publisher

Inst Arctic Alpine Res

Place of publication

Univ Colorado, Boulder, USA, Co, 80309

Rights statement

© 2017 Regents of the University of Colorado

Repository Status

  • Restricted

Socio-economic Objectives

Other environmental management not elsewhere classified

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC