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Vertebrate grazers have been shown to be a critical element in maintaining lawns, although lawns can also form in places without such herbivores. In Tasmania lawns are widespread in lentic wetlands. We used environmental observations and exclosure experiments at two altitudinally contrasting lentic wetland lawns, and waterlogging experiments, to test the hypotheses that their structure is maintained (i) periodic inundation; and (ii) grazing.Waterlogging experiments and field observations demonstrated that the two main invading shrubs were indifferent to immersion for several months and that the distribution of the lawns was independent of inundation period, results inconsistent with the first hypothesis. The exclosure experiments showed that both woody and non-woody plants became taller in the lawns when marsupial grazers and rabbits were excluded. It therefore seems that the lawn structure is maintained by grazing and that alternative structural states result from exclusion of grazing pressure in less than 2 years.

Item Type:	Refereed Article
Keywords:	grazing, lawn, lentic wetlands, marsupials, short herbfield, shrub invasion, Tasmania, waterlogging.
Research Division:	Environmental Sciences
Research Group:	Environmental Science and Management
Research Field:	Conservation and Biodiversity
Objective Division:	Environment
Objective Group:	Land and Water Management
Objective Field:	Sparseland, Permanent Grassland and Arid Zone Land and Water Management
Author:	Roberts, Cynthia (Ms Roberts)
Author:	Kirkpatrick, JB (Professor James Kirkpatrick)
Author:	McQuillan, PB (Mr Peter McQuillan)
ID Code:	65191
Year Published:	2011
Web of Science® Times Cited:	9
Deposited By:	Geography and Environmental Studies
Deposited On:	2010-10-12
Last Modified:	2012-08-03
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