Research Report No. 361
Establishment of E. tricarpa (red ironbark) from planted seedlings in the lowland forests of East Gippsland. M. T. Lutze. March 1998. 13pp. (unpubl.)
SUMMARY
The species diversity of the lowland forests of East Gippsland has declined as a result of selective harvesting and poor regeneration of durable timber species, such as E. tricarpa (red ironbark). The objective of this experiment was to determine whether E. tricarpa could be successfully regenerated by planting nursery-grown seedlings and to determine the effect of overwood removal, understorey removal and protection from browsing by tree guards on regeneration success, as indicated by survival and early growth.
At nine years after planting, it was found that survival was adequate in all treatments and that height growth was the important indicator of success. The most important factor determining success was overwood removal. Protection of seedlings from browsing by tree guards also greatly improved success, but was not critical. Understorey removal did not greatly improve success, but its effect may have been confounded by overwood removal.
The results indicate the following operational treatments are likely to be the most cost-effective means of obtaining successful regeneration of E. tricarpa from planting after harvesting.
- Remove overwood by falling as timber products or to waste or by poisoning or sapringing, then
- Plant into burnt, disturbed and/or vegetation-free areas on an opportunistic basis, then
- Protect seedlings from browsing with fencing or tree guards, if funds are available.
Further research is required into the effect of gap size on the relative growth rates of E. tricarpa and other species in the lowland forest. This could have important implications for the maintenance of species diversity.