University of Tasmania
Browse

File(s) under permanent embargo

Alternative stable states and the role of fire-vegetation-soil feedbacks in the temperate wilderness of southwest Tasmania

journal contribution
posted on 2023-05-17, 10:25 authored by Wood, SW, David BowmanDavid Bowman
Two ecological models have been put forward to explain the dynamics of fire-promoting and fire-sensitive vegetation in southwest Tasmania: the alternative stable states model of Jackson (in Proc Ecol Soc Aust 3:9–16, 1968) and the sharpening switch model of Mount (in Search 10:180–186, 1979). Assessing the efficacy of these models requires high resolution spatio-temporal data on whether vegetation patterns are stable or dynamic across landscapes. We analysed ortho-rectified sequences of aerial photography and satellite imagery from 1948, 1988 and 2010 to detect decadal scale changes in forest and nonforest vegetation cover in southwest Tasmania. There was negligible change from forest to non-forest (\0.05%) and only a modest change from non-forest to forest over the study period. Forest cover increased by 4.1% between 1948 and 1988, apparently due to the recovery of forest vegetation following standreplacing fire prior to 1948. Forest cover increased by 0.8% between 1988 and 2010, reflecting the limited ability of forest to invade treeless areas. The two models include interactions between vegetation, fire and soil, which we investigated by analysing the chemical (phosphorus, nitrogen) and physical properties (clay, silt) of 128 soil samples collected across 34 forest–non-forest boundaries. Phosphorus in the upper horizon was typically lower in non-forest vegetation compared to forest vegetation, which is consistent with proposed fire–vegetation–soil feedbacks. Mineral horizons were dominated by sand, with low levels of clay under all vegetation types. Available field evidence lends support to the Jackson (1968) alternative stable states model as the most suitable model of vegetation dynamics on nutrient poor substrates in southwest Tasmania although modifications of the timeframes for transitions toward rainforest are required.

History

Publication title

Landscape Ecology

Volume

27

Pagination

13-28

ISSN

0921-2973

Department/School

School of Natural Sciences

Publisher

Springer Netherlands

Place of publication

Van Godewijckstraat 30, Dordrecht, 3311 GX, NE

Rights statement

Copyright 2011 Springer Science+Business Media B.V.

Repository Status

  • Restricted

Socio-economic Objectives

Terrestrial biodiversity

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC