Alternatives to broadcast burning in the northern interior of British Columbia: Short-term tree results

We compared the growth and foliar nutrients of lodgepole pine and hybrid wh ite spruce following mechanical site preparation treatments and broadcast b urning in a high-elevation plantation in north-central British Columbia. Af ter five years, the largest trees were found on the broadcast burn (44% inc rease over raw planting), followed by disc-trenching (26% increase), and th en windrow piling (9% increase). Height increment was similarly significant ly different between treatments after seven years. Equal increases in nitro gen, phosphorus, and sulphur foliar concentrations were found across all si te preparation treatments compared to controls. Foliar nutrients alone, how ever, did not further explain the differences in tree productivity between site preparation treatments. The results demonstrated how some sites can be nefit from site preparation, in the short-term at least, and also emphasize d the positive role fire can have on forest productivity.