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https://hdl.handle.net/1959.11/2859
Title: | Experiments on tree and shrub establishment in temperate grassy woodlands: Seedling survival | Contributor(s): | Clarke, Peter John (author) | Publication Date: | 2002 | DOI: | 10.1046/j.1442-9993.2002.01221.x | Handle Link: | https://hdl.handle.net/1959.11/2859 | Abstract: | Experimental studies of the emergence of shrubs and trees in grassy woodlands on the New England Tablelands, New South Wales, Australia, showed that emergence of seedlings was determined by seed supply, seed predators and seed burial. The survival of these seedlings was then observed in an experiment to test the effects of previous land use, grazing by stock and grazing by other vertebrates. The fate of four eucalypts and six shrub species was followed over 5 years. Across all species more than 50% mortality occurred in the first 6 months prior to the imposition of grazing treatments. These deaths were attributed to the combined effects of insect defoliation, cold, and low soil moisture. Average mortality over all treatments showed two distinct trends: eucalypts and one unpalatable shrub ('Leptospermum') had greater than 1% survival over 5 years, whereas 'Acacia', 'Cassinia', 'Indigophera', 'Lomatia' and 'Xanthorrhoea' either had very low or no survival after 5 years. The effect of livestock grazing on seedling numbers was rarely detected because of patchy emergence and mortality due to other causes. However, proportional hazard regression models showed that there was often an increased hazard associated with grazing or grazed landscapes. Overall, those species with high hazard coefficients associated with stock are rare in the landscape, whereas those with lesser risk are more common. Recruitment is likely to be an extremely rare event because the highest proportion of germinable seed sown that survived to a juvenile stage was 0.42% and the mean across all species was 0.12%. No natural recruitment of shrub species was observed over 5 years of observation, suggesting that recruitment is episodic and disturbance driven. Enhancing natural 'regeneration' of woody plants under these circumstances may be more challenging than simply fencing off remnants. | Publication Type: | Journal Article | Source of Publication: | Austral Ecology, 27(6), p. 606-615 | Publisher: | Blackwell Publishing Ltd | Place of Publication: | Australia | ISSN: | 1442-9993 1442-9985 |
Fields of Research (FoR) 2008: | 060799 Plant Biology not elsewhere classified | Socio-Economic Objective (SEO) 2008: | 960806 Forest and Woodlands Flora, Fauna and Biodiversity | Peer Reviewed: | Yes | HERDC Category Description: | C1 Refereed Article in a Scholarly Journal | Publisher/associated links: | http://nla.gov.au/anbd.bib-an21420942 |
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Appears in Collections: | Journal Article |
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