A joint research programme has been initiated between Forest Research, New Zealand and Forintek Canada Corp., Canada, to determine the role of mechanical tree harvesters on disseminating fungal inoculum into logs. Mechanical harvesters cause loosening and removal of bark and also damage the surface of the wood with their feed rollers leaving indentations up to several centimetres deep. Results of New Zealand trials are reported in this paper. Fungal isolations from mechanically harvested logs in a Central North Island forest were undertaken over four New Zealand seasons from log regions showing damage induced by the harvester. In the autumn, winter and spring, samples were also taken from standing trees and the head of the mechanised harvesters. Sapstain, mould and decay fungi were isolated from surface and sub-surface regions of logs showing damage typical of that caused by mechanical harvesters. Similar types of fungi were also isolated from the bark of standing trees and the head of the mechanical harvester. Decay fungi and moulds represented the prevailing types of fungi isolated over winter and spring with decay being prevalent in the summer and autumn of 2001. Sphaeropsis sapinea (Fries) Dyko & Sutton, was common in radiata pine plantations in the Central North Island during summer, but increasingly fewer isolations were made during spring, winter and autumn respectively.

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