New Zealand Journal of Forestry (1979) 24(2): 288–300
©New Zealand Institute of Forestry
Choosing the best provenances of radiata pine for different sites in New Zealand
C.J.A. Shelbourne , R.D. Burdon , M.H. Bannister and I.J. Thulin
Results from two sets of provenance experiments with Pinus radiata planted on several sites shed fresh light on the pattern of provenance-site adaptation in this species. An early trial measured at age 21 years indicated that a Huckleberry Hill population from Monterey grew faster relative to the New Zealand select tree progenies at Golden Downs than it did at Gwavas, and that it might well surpass an unselected New Zealand base population in growth rate at Golden Downs.
During 1964-68, trials of all the five native populations were planted at two sites in Kaingaroa, and at Gwavas, Santoft and Golden Downs. Measurements at 6V2 to 8 years showed that a composite New Zealand population (from Nelson and Kaingaroa) outgrew the native populations by about 20% in volume per tree at Kaingaroa and at Gwavas. However, at Golden Downs (Nelson) and Santoft (Manawatu sand dunes) the volume growth of the New Zealand population was equalled or slightly exceeded by the Monterey population. In view of the current advantages possessed by the cultivated New Zealand population, which apparently did not suffer inbreeding depression and has undergone some natural and silvicultural selection, this result suggests that improved seed from the Monterey population would ultimately have a real advantage on these sites.
There is a need to explore more intensively the pattern of provenance-site interactions in P. radiata, and to this end seed has recently been collected from the Californian mainland stands for further provenance trials and selection plantings.