Spread of radiata pine into indigenous vegetation in North-eastern Victoria.  G. Minko and B. C. Aeberli.  August 1982.  13 pp. (unpubl.)

SUMMARY

The spread of natural regeneration of Pinus radiata D. Don (radiata pine) from plantations into the surrounding peppermint-type eucalypt forests in North-eastern Victoria (in terms of number of plants and distance from the plantations in 1981) was found to depend on the topography of the plantation boundary and its exposure to, and the direction of, prevailing winds. The survival and establishment of young pines depended on the absence of fire and grazing, and therefore was affected by land ownership and management practices. Also, the pines did not become established among tall bracken. At present, very few self-sown pines in the eucalypt forest have developed to the cone-bearing stage, therefore seed supply for continued spread is still derived from the plantations.

The maximum distances away from the plantation boundary at which pine regeneration was recorded where 1.5 and 1.2 km to the south and east respectively, and only 0.4 km to both the north and west; this appears to demonstrate a strong influence of summer northerlies and westerlies. The spread of pines was greatly reduced when the plantation boundary was sheltered by the topography of adjacent eucalypt forest.

The distribution of pines away from plantation boundaries exposed to wind was used to estimate the expected maximum density of regeneration in peppermint-type forests in North-eastern Victoria. Results indicated that one pine per hectare could be expected 2.7 and 0.8 km to the south and east of exposed plantation boundaries respectively, but only 0.4 km to the north and west.

Not all eucalypt forests appear to be receptive to invasion by P. radiata, as no young pines were observed in a forest type containing Eucalyptus blakelyi Maiden (Blakely’s red gum) surrounding a plantation near Chiltern.

Also published:

Minko, G. and Aeberli, B.C. (1985)  Spread of radiata pine into indigenous vegetation in North-eastern Victoria.  Dep. Conserv., For. and Lands, State For. and Lands Serv., For. Tech. Pap. 30: 7-25.