UBC Undergraduate Research

The effects of ground-based harvesting on coastal British Columbia soils : mitigating the negative consequences Trommel, Steve

Abstract

The recent downturn in British Columbia’s coastal forest industry, together with an increased proportion of timber harvest from second growth stands has increased pressure on harvest operations to reduce costs. Using ground-based harvest methods, primarily with skidders and hoe-chuckers, harvest operations can lower costs compared to cable yarding. Skidders and hoe-chuckers have the potential to negatively affect future site productivity and natural hydrological processes. The complexity of factors influencing the amount of soil disturbance resulting from skidder and hoe-chucker use makes the interpretation of research results difficult. The strongest factors are soil moisture at time of harvest and soil texture. Short term research on seedling growth has found a decrease in growth on machine trails of 20 to 53 percent (Senyk & Craigdallie, 1997). The difference in growth between machine trails and undisturbed areas decreases over time. Increased growth on the margins of machine trails has been shown to partially offset losses to growth on trails. Direct hydrological impacts from ground-based machinery have not been researched in great depth as hydrological processes are also complex. Case studies have shown the potential of ground-based harvesting to change water flow patterns resulting in mass wasting and drainage structure failures. The negative of consequences of ground-based harvesting can be mitigated by reducing harvest during very wet periods and through the use of designated trails, rehabilitating trails, proper equipment choice and operator training.

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Attribution-NonCommercial-NoDerivatives 4.0 International