Historical and current land use shape landscape restoration options in the Australian wheat and sheep farming zone

Abstract:

A significant challenge for policy and land management is to alter agricultural systems to reduce their detrimental impacts on native vegetation and biodiversity habitat. We analysed historical, ecological and land use data to understand the threats to native vegetation, and prospects for future recovery in the wheat-sheep zone of the Wimmera and Mallee in southeastern Australia. We analysed air photos, surveyed 60 remnant vegetation sites, and interviewed land managers about a subset of 35 remnants. Our analysis confirmed that soil types favoured for cropping were largely cleared before 1945; mean cover declined from 8% to 5% between 1945 and 2000. Small patches (<5 ha) account for a quarter of remaining woody cover. Cover of crops increased at the expense of pasture. Small patches were typically frequently grazed, nutrient enriched and were dominated by an exotic annual understorey. Recruitment of woody species was uncommon, and non-existent in the small patches. Landholders valued small patches primarily for stock shelter but without recruitment their long-term persistence is doubtful, even though most farmers are grazing less now compared with 30 years ago. Meeting regional native vegetation cover targets likely depends on retention of all existing vegetation patches, plus considerable revegetation. However, although current land use trends allow the sparing of some marginal lands while cropping intensifies, this option cannot satisfy vegetation cover targets and may not preserve biodiversity. More significant gains in native vegetation cover may not occur unless new opportunities arise for the current cohort of farmers. Crown Copyright © 2008.

Año de publicación:

2009

Keywords:

• Intensification
• native vegetation
• land use change
• Biodiversity
• grazing

Fuente:

scopus