Passive brigalow (Acacia harpophylla) woodland regeneration fails to recover floristic composition in an agricultural landscape

Le Brocque, Andrew F. and Wagner, Peter M. (2018) Passive brigalow (Acacia harpophylla) woodland regeneration fails to recover floristic composition in an agricultural landscape. Austral Ecology. pp. 1-15. ISSN 1442-9985

Abstract

Regrowth (secondary) vegetation is increasingly seen as an important conservation alternative where there is inadequate cover of intact remnant, and more recently, the focus of potential biodiversity offsets. However, little is known of the functioning and dynamics of regrowth in comparison to remnant vegetation. This research tests whether the floristic composition and stand structure of brigalow (Acacia harpophylla) regrowth woodlands return to that of endangered brigalow remnant woodlands and the relationships of patterns in composition and structure to environmental drivers in the agricultural landscape of southern Queensland, Australia. Thirty-eight sites were sampled for species composition (frequency), stand structure (foliage projected cover of strata) and environmental variables (spatial/patch characteristics), encompassing ungrazed and grazed old-growth brigalow remnants and different aged brigalow regrowth (<20; 20–30; 30–40; >40 years since clearing). There was no difference in structure observed between grazed remnant and older regrowth (>40 years); however, ungrazed old-growth remnants were structurally different to older regrowth. Ungrazed and grazed old-growth remnants were compositionally different to all regrowth woodlands. The proportion of surrounding vegetation, landuse type, patch grazing intensity and soil properties, were highly correlated with patterns in composition and stand structure observed across the brigalow woodlands. While the stand structure of brigalow regrowth returns to that of remnant brigalow, the distinct floristic species composition of older regrowth may indicate a longer time period is needed for equivalence or a possible alternate stable state in these highly modified agricultural landscapes. To ensure the long-term persistence of brigalow communities, further investigation of the development trajectory of brigalow regrowth is required; however, it is critical that intact brigalow remnant vegetation remains a priority for conservation strategy and policy.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Published online 6 Feb 2018. Permanent restricted access to ArticleFirst version in accordance with the copyright policy of the publisher.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - School of Agricultural, Computational and Environmental Sciences
Date Deposited: 19 Feb 2018 01:54
Last Modified: 14 May 2018 23:41
Uncontrolled Keywords: brigalow woodland, Acacia harpophylla, regrowth, remnant, floristic composition, stand structure
Fields of Research : 06 Biological Sciences > 0602 Ecology > 060202 Community Ecology(excl. Invasive Species Ecology)
05 Environmental Sciences > 0502 Environmental Science and Management > 050202 Conservation and Biodiversity
05 Environmental Sciences > 0501 Ecological Applications > 050104 Landscape Ecology
Socio-Economic Objective: D Environment > 96 Environment > 9613 Remnant Vegetation and Protected Conservation Areas > 961306 Remnant Vegetation and Protected Conservation Areas in Forest and Woodlands Environments
Identification Number or DOI: 10.1111/aec.12578
URI: http://eprints.usq.edu.au/id/eprint/33670

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