Vegetation change and ecological processes in alpine and subalpine Sphagnum bogs of the Bogong High Plains, Victoria, Australia

Citation
Cha. Wahren et al., Vegetation change and ecological processes in alpine and subalpine Sphagnum bogs of the Bogong High Plains, Victoria, Australia, ARCT ANTARC, 33(3), 2001, pp. 357-368
Citations number
66
Categorie Soggetti
Multidisciplinary
Journal title
ARCTIC ANTARCTIC AND ALPINE RESEARCH
ISSN journal
15230430 → ACNP
Volume
33
Issue
3
Year of publication
2001
Pages
357 - 368
Database
ISI
SICI code
1523-0430(200108)33:3<357:VCAEPI>2.0.ZU;2-H
Abstract
Sphagnum bogs that were monitored over a 15-yr period showed significant ch anges in the abundance of diagnostic species. At plots ungrazed by cattle, the major bog species Sphagnum cristatum, Caltha introloba, and Carex gaudi chaudiana increased significantly in cover. No such increases occurred in g razed plots. There were few changes in cover of the main structural vegetat ion types-closed heathland, low open heathland, and open herbfield on stony pavements. Sphagnum and the main herbfield species, Oreobolus pumilio and Caltha introloba, were dislodged and shifted over unvegetated stony pavemen ts by snowmelt runoff, snowpack movement, and cattle trampling. Experiments using Sphagnum transplants showed this species capable of colonizing pavem ents by establishing on other plants. Survival and growth of transplants we re significantly greater on low compared with high water flow (high energy) sites. Grazing and trampling by cattle significantly reduced survival of t ransplants. thus disrupting the colonization of pavements; firstly, by dire ctly reducing the survival and growth of Sphagnum and other colonists; and secondly, by preventing the formation of barriers to water flow that would facilitate colonization. We propose a successional dynamic based on some of the processes operating in the open herbfield and stony pavements of Sphag num bogs.