Murdoch University Research Repository

Welcome to the Murdoch University Research Repository

The Murdoch University Research Repository is an open access digital collection of research
created by Murdoch University staff, researchers and postgraduate students.

Learn more

After the fence: Soil and vegetation condition in grazed, fenced and benchmark eucalypt woodlands of fragmented agricultural landscapes

Prober, S., Standish, R. and Wiehl, G. (2011) After the fence: Soil and vegetation condition in grazed, fenced and benchmark eucalypt woodlands of fragmented agricultural landscapes. Australian Journal of Botany, 59 (4). pp. 369-381.

[img]
Preview
PDF - Authors' Version
Download (451kB) | Preview
Link to Published Version: http://hdl.handle.net/102.100.100/104104?index=1
*Subscription may be required

Abstract

Ecological theory predicts that vegetation changes caused by introduction of livestock grazing may be irreversible after livestock are removed, especially in regions such as Australia that have a short evolutionary exposure to ungulate grazing. Despite this, fencing to exclude livestock grazing is the major tool used for restoring biodiversity in remnant vegetation degraded by grazing in Australian agricultural landscapes. To characterise benefits and limitations of livestock exclusion for enhancing biodiversity in forb-rich York gum (Eucalyptus loxophleba subsp. loxophleba) – jam (Acacia acuminata) woodlands, we compared 29 fenced remnants from across the central Western Australian wheatbelt with 29 adjacent grazed remnants and 11 little-grazed ‘benchmark’ woodlands. We explored two hypotheses: (1) fencing to exclude livestock facilitates recovery of grazed woodlands towards benchmark conditions, and (2) after fencing, recovery of grazed woodlands to benchmark conditions is constrained by ecological or other limits. Our first hypothesis was supported, with fenced remnants more similar to benchmark woodlands in tree recruitment, exotic cover, native cover, native plant richness and plant species composition than grazed remnants were. Further, exotic cover decreased and frequency of jam increased with time since fencing (2–22 years). However we found no evidence for recovery of nutrient-enriched topsoils due to fencing. Our second hypothesis was also supported, with higher soil nutrients and exotic cover, lower native plant richness and different plant species composition in fenced compared with benchmark woodlands. Regression analyses suggested recovery of native species richness can be constrained by exotic species that persist after fencing, which in turn are more persistent at higher soil nutrient concentrations. We conclude that fencing to exclude livestock grazing is valuable for biodiversity conservation. However, consistent with ecological theory, additional interventions are likely to be necessary to achieve some conservation goals or to promote recovery in more productive (nutrient-enriched) sites.

Item Type: Journal Article
Publisher: CSIRO Publishing
URI: http://researchrepository.murdoch.edu.au/id/eprint/55619
Item Control Page Item Control Page

Downloads

Downloads per month over past year