Miller, AM and O'Reilly-Wapstra, JM and Potts, BM and McArthur, C, Technical report 195 TCFA research into alternatives to the use of 1080: Manipulating seedling palatability for non-lethal browsing management, Department of Primary Industries, Parks, Water & Environment, 195 (2009) [Consultants Report]
Copyright 2009 CRC Forestry
Browsing by marsupial herbivores is a major problem in plantation forestry. This has traditionally been controlled through a reduction in herbivore numbers achieved by lethal means. The mammal browsing group at the University of Tasmania and the CRC for Forestry has been researching non-lethal alternatives for over a decade and found that the most effective methods involved manipulating seedling palatability prior to planting and in the field. Specifically, the use of naturally resistant seedling stock, chemical repellent, modification of nursery fertiliser regime and use of natural vegetation on coupes have all proven successful in deterring feeding. Additionally, since 2007, the use of mesh stockings to protect plantation seedlings has become quite popular within the forestry industry, but data to confirm their effectiveness in reducing browsing is lacking.
This study combined extensive browsing research to operationally test the most effective combination of non-lethal methods listed above. Treatment combinations were planted in eight field sites across Tasmania. Experimental seedlings were planted in replicated blocks spread in a single row around the perimeter of operational coupes. Seedlings were monitored regularly for browsing damage, with seedling height and characteristics of the surrounding vegetation being assessed periodically. We found that the most effective treatments at reducing the severity of browsing damage in the short term were seedling stockings and a combination of chemical repellent (Sen-Tree) and low nursery fertiliser.
Stockings and repellent were then tested in further trials to demonstrate the effectiveness of these treatments across a range of sites and during winter, as opposed to spring plantings. Here we used six field sites and followed the same basic design as the initial trial. Stockings and repellent were tested in isolation, in combination, and with versus without field application of repellent. We found that the combination of stockings and repellent was the most effective, and resulted in a significant delay in browsing and a reduction in browse severity over 24 weeks, compared with control seedlings.
These results have important and immediate implications for tree growers. Stockings and/or repellent can be applied to seedlings in the nursery to significantly delay the onset of browsing and reduce its severity when planted in the field. In areas with low browsing intensity, this could be enough to reduce browsing in itself; in other areas the browsing delay could be enough to allow alternative controls to be implemented. The long-term effectiveness of stockings needs to be determined (e.g. effects on seedling growth and form) and the issue of continued repellent re-application needs to be addressed.
|Item Type:||Consultants Report|
|Research Division:||Biological Sciences|
|Research Field:||Behavioural Ecology|
|Objective Division:||Plant Production and Plant Primary Products|
|Objective Field:||Forestry not elsewhere classified|
|Author:||Miller, AM (Dr Alison Miller)|
|Author:||O'Reilly-Wapstra, JM (Dr Julianne O'Reilly-Wapstra)|
|Author:||Potts, BM (Professor Brad Potts)|
|Author:||McArthur, C (Dr Clare McArthur)|
|Deposited By:||Plant Science|
|Downloads:||231 View Download Statistics|
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