Résumé :
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La présente étude de l'Institut canadien de recherches en génie forestier (FERIC) a été réalisée en Colombie-Britannique et en Alberta durant la période 1990 à 1994. L'industrie forestière de l'ouest du Canada s'était montrée préoccupée par la possibilité que les stocks de plantation soient manipulés et transportés de façon inappropriée avant leur arrivée sur le site à reboiser, ce qui pouvait avoir un effet nuisible sur leur croissance et leur survie. Comme les stocks de plantation sont chargés et déchargés à plusieurs reprises, ils ont de nombreuses occasions d'être manipulés " brusquement ". Les objectifs de l'étude visaient : à déterminer la fréquence et l'ampleur des chocs mécaniques subis par les semis au cours de leur manutention et de leur transport entre la pépinière et le site de reboisement ; et à déterminer si ces chocs causaient des effets biologiques néfastes aux semis.
The Forest Engineering Redearch Institute of Canada (FERIC) carried out a study from 1990 to 1994 to monitor shocks to seedling manting stock during transport from nursery to the planting site in normal commercial reforestation operations. Magnitude and exact time of mechanical shocks were measured by a recorder placed inside seedling boxes. Seedlings transported by regrigerated semitrailer, 5-t truck, pickup truck, small trailer, and all-terrain vehicles were monitored in Alberta and British Columbia. Number of shocks, peak acceleration, and average drop height were tabulated for travel on both paved and gravel roads. Twenty-two trials involving seven species were established at nurseries and field locations covering several ecological zones in both provinces. Cold-stored, cool-stored, and freshly lifted seedlings were used in the trials. Seedlings were given two mechanical drop treatments by dropping them 30 times from 0,5-m and 30 times from 1.0-m, respectively. Control seedlings were not dropped. Treatments were applied to nursery trial seedlings not exposed to normal handling and transport, and to field trial seedlings after transport to the planting site. Six root growth potential tests were made with trated and control seedlings in conjunction with the nursery trials. Seedling survival and volume growth were recorded for two growing seasons, and results were statistically analyzed.
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