The re-establishment of indigenous vegetation on a mountain ash site at Narbethong following a rotation of radiata pine.  W.D. Incoll and A.B. Sumner.  December 1975.  22 pp. (unpubl.)

SUMMARY

In a trial established at Narbethong in 1970, three plots at an altitude of about 820m were seeded and planted with ash eucalypts following a rotation of Pinus radiata. Assessment at age three years showed that survival and height growth were greater on the site occupied by pine six months previously (seedling survival 23,000 plants/ha of mean height 3.5m, and planting survival 78-81% of mean heights 4.0-5.4m) and poorest on the site occupied by pine 30 years previously (seedling survival 0 and planting survival 75-100% of mean height 2.2-5.5m).

A more extensive trial was established in 1971 at an altitude of 730m on a site occupied by pine 6 months previously. Assessment at age two years showed good survival of seeded and planted eucalypts and exceptional height growth (seedling survival 19,800-26,200 plants/ha of mean height 4.0m, and planting survival 57-74% of mean height 3.4-4.6m).

If the radiata pine were to affect subsequent re-establishment of eucalypts it would be expected that survival and growth of the eucalypts would be poorest on sites most recently occupied by pine. As this was not the case it was concluded that a pine rotation does not prejudice the subsequent re-establishment of eucalypts on these sites.

The plant communities which regenerated on the pine sites were compared with those on regenerating eucalypts sites. A chi-square comparison of diversity and cover by habit classes showed that the eucalypt regeneration on an area previously occupied by pine had similar species diversity and percentage cover to the regeneration which developed on sites which had never carried pine. Although two herb species found on the latter sites were not found on sites previously occupied by pine, there was not sufficient evidence to attribute their absence to the presence of a radiata pine rotation. Thus, it appears that at Narbethong the conversion of mountain ash sites to radiata pine is not an irreversible change, and that an almost complete suite of flora will re-occupy such sites if they are sown or planted with eucalypts after a rotation of pine.

Also published:

Incoll, W.D. (1977)  Re-establishment of eucalypts following a rotation of radiata pine.  For. Comm. Vic., For. Tech. Pap. 26: 11-17.