Is 'vegetation thickening' occurring in Queensland's mulga lands - a 50-year aerial photographic analysis

Witt, G. B., Harrington, R. A. and Page, M. J. (2009) Is 'vegetation thickening' occurring in Queensland's mulga lands - a 50-year aerial photographic analysis. Australian Journal of Botany, 57 7: 572-582. doi:10.1071/BT08217

Author Witt, G. B.
Harrington, R. A.
Page, M. J.
Title Is 'vegetation thickening' occurring in Queensland's mulga lands - a 50-year aerial photographic analysis
Journal name Australian Journal of Botany   Check publisher's open access policy
ISSN 0067-1924
Publication date 2009-12-21
Year available 2009
Sub-type Article (original research)
DOI 10.1071/BT08217
Volume 57
Issue 7
Start page 572
End page 582
Total pages 11
Editor Bob Hill
Simone Farrer (Managing Editor)
Place of publication Ausralia
Publisher CSIRO Publishing
Collection year 2010
Language eng
Subject C1
050299 Environmental Science and Management not elsewhere classified
960910 Sparseland, Permanent Grassland and Arid Zone Land and Water Management
Abstract Changes in the density of woody vegetation in arid and semiarid rangelands have the potential to dramatically reduce productivity as well as adversely affect ‘natural’ ecosystem processes. Many parts of Australia are believed to have experienced thickening of woody vegetation since European occupation and the associated changes to fire and grazing regimes that followed. Unfortunately there is little empirical evidence to support a widely held perception of thickening. This study analyses the available historical aerial photographic coverage for the mulga lands bioregion of south-western Queensland, Australia; a record spanning the second half of the twentieth century. Changes in woody vegetation canopy cover were assessed for 190 sites. More than half of the sites had no evidence of mechanical disturbance and thus reflected general, or background trends in woody vegetation cover. The region-wide average extent of change on these undisturbed sites was estimated to be approximately a 3.6% increase in canopy cover over the study period. Thus, a trend toward vegetation thickening was detected. However, large variation was observed depending on the land systems and rainfall zone where sites were located. The results are discussed in the context of century scale climate variability and perceptions of vegetation change and a tentative explanatory model is presented to account for the observed data.
Keyword Tree-Grass Dynamics
New South Wales
Australian Savanna
Cover Change
Q-Index Code C1
Q-Index Status Confirmed Code

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2010 Higher Education Research Data Collection
School of Agriculture and Food Sciences
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 12 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 10 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Sun, 03 Jan 2010, 00:05:07 EST