ACRIS Climate Variability Update 2005-2011: Updated information to that provided in Rangelands 2008 – Taking the pulse

ACRIS Climate Variability Update 2005-2011: Updated information to that provided in Rangelands 2008 – Taking the pulse Report

  • Author(s): Bastin, GN
  • Published: 2012
  • Publisher: Australian Government Department of Sustainability, Environment, Water, Population and Communities

Abstract: In 2008, ACRIS documented changes in the rangelands at national and regional scales in the report Rangelands 2008-Taking the Pulse. That report was based on data for the period 1992 to 2005. Recent years have well illustrated the extreme climate variability that Australia experiences, with much of the continent changing from severe drought during parts of the last decade to some locations experiencing their wettest period on record. This document provides updated information on seasonal quality of bioregions across the rangelands, using data on annual (autumn to autumn) rainfall and modelled pasture growth. ‘Seasonal quality’ is the term ACRIS uses to rank the degree of climate variability from one year to the next. Seasonal quality broadly describes the relative value of recent rainfall on biological functioning. Relative value (quality) is judged with reference to the longer term record. ‘Biological functioning’ broadly means vegetation growth as a basic resource for both livestock (forage) and fauna (food, shelter). In summary: - Rainfall was below average to average across much of the eastern and central rangelands between 2005-06 and 2007-08 (i.e. poorer seasonal quality). - Seasonal quality then improved across the eastern rangelands, based on rainfall, but remained poor in pastoral Western Australia, particularly in 2009-10. - The rangelands have experienced very good seasonal conditions over the last two years (2010-11 and 2011-12) with annual rainfalls being amongst the highest recorded for many bioregions. - Modelled pasture growth provides an alternative indicator of seasonal quality. It indicates the potential for pasture growth based on rainfall, soil quality and regional grazing pressure by livestock, feral herbivores and kangaroos. In some areas, this potential may not be realised because of past land degradation. Modelled pasture growth generally supported the spatial and temporal patterns of seasonal quality indicated by rainfall but there were some regional differences. In particular, pasture recovery tended to lag rainfall coming out of the recent drought in the southern and eastern rangelands. Further, in several tropical northern bioregions much of the increased rainfall was less effective, indicated by smaller responses in the pasture growth index in most years.

Cite this document

Suggested Citation
Bastin, GN, 2012, ACRIS Climate Variability Update 2005-2011: Updated information to that provided in Rangelands 2008 – Taking the pulse, Report, viewed 13 June 2024, https://www.nintione.com.au/?p=4999.

Endnote Mendeley Zotero Export Google Scholar

Share this page

Search again