Ref ID: 8303
Ref Type: Journal
Authors: Close, D. C., Beadle, C. L., Holz, G. K., and Brown, P. H.
Pub Date: 2001
Journal Name: Australian Journal of Botany
Volume: 50
Issue: 1
Start Page: 15
End Page: 20
ISBN/ISSN: 0067-1924
Keywords: environment/Eucalyptus/Eucalyptus globulus/Eucalyptus nitens/frost/growth/nursery/plantation/seedling/temperature/effect/tree/photoinhibition/species/site/establishment/mortality/contrast/height/tolerance/response/anthocyanin
Abstract: The effects of shadecloth tree shelters on cold-induced photoinhibition, foliar anthocyanin and growth of Eucalyptus globulus and Eucalyptus nitens seedlings was assessed between planting and age 23 weeks. Seedlings were raised under relatively mild nursery conditions then planted in early spring. Half the planted seedlings of each species were immediately shaded by open-topped 50 % shadecloth tree shelters. The experimental site was at 350 m asl. which is considered marginal for establishment of E. globulus plantations due to low mean minimum temperatures. Cold and sunny conditions after 6 overnight frosts within 3 weeks of planting induced severe photoinhibition in non-shaded seeldings. This was associated with increased anthocyanin to moderate and high levels and moderate and severe photodamage in non-shaded E. nitens and E. globulus, respectively. As a result there was 20% mortality in non-shaded E. globulus. In contrast in shaded seedlings, levels of photoinhibition and anthocyanin remained largely similar to those before planting and there was no photodamage. Height growth of non-shaded E. nitens was not detrimentally affected compared to shaded E. nitens. In contrast, shaded E. globulus had greater height growth from 8 weeks after planting and thereafter compared to non-shaded E. globulus. It is concluded that cold-induced photoinhibition is a factor determining the range of environments where E. globulus can be successfully planted and not frost tolerance alone. Differences in anthocyanin levels between treatments at 5 weeks after planting, decreasing levels with increasing air temperatures and decreasing photoinhibition of non-shaded seedlings after five weeks after planting and increased levels in response to shadecloth removal indicate that anthocyanin was synthesised in response to increased photoinhibition and that levels were related to the severity of the photoinhibition in E. globulus and E. nitens seedling during establishment
Notes: Entered by Dugs (30/1/2001):
Reprint: Not in File
Program: SPF Sustainable Management
Project: B3
Deliverable: B3-5.1
Confidentiality: Public
Availability: Authors
Report: Annual Report 2001/2
Type: Article
Address: dugald.close@ffp.csiro.au