Commercial thinning of lodgepole pine in Alberta - 15-year growth response

米勒西部森林产品有限公司经营两个锯木厂，纸浆厂，并在阿尔伯塔山麓的怀特库尔社区附近的相关林地业务。由于火灾和山松甲虫爆发的影响，预计该地区的短期至中期木材供应将减少。商业间伐是一个潜在的选择，增加中期锯木木材供应，在这些lodgepole松树森林减少所需的时间，为个别树木达到可销售的大小。商业间伐还将立即产生可销售的木材，并通过收获未来的死亡率（即捕获自然排水），在轮伐期内可能捕获更大的体积。然而，有许多问题与树木生长反应和死亡率在不同的网站类型，仍然必须解决商业间伐可以在整个景观操作之前。米勒西部在1996年至2003年期间对32块地块进行了间伐，并沿着未间伐的对照地块每五年重新测量一次。这项工作的目的是量化和解释的树木生长反应（包括单株树和林分水平），以商业间伐在成熟的火炬松林分的不同年龄和不同的网站类型。加拿大林业部门直接雇用了超过20万人，为国民经济贡献了230亿美元。这一重要行业依赖于可持续的生长木纤维供应，而这种供应正面临减少的风险。加强森林管理的做法，如商业性间伐，为解决这一问题提供了一个可能的办法。

Millar Western Forest Products Ltd. operates two sawmills, a pulp mill, and associated woodlands operations near the community of Whitecourt in the Alberta foothills. There is an expected decrease in the short to mid-term timber supply in this region due to the impacts of fires and the mountain pine beetle outbreak. Commercial thinning is a potential option for increasing mid-term sawlog timber supply in these lodgepole pine forests by decreasing the time needed for individual trees to reach merchantable size. Commercial thinning will also produce merchantable timber immediately and potentially capture greater volume over the course of a rotation by harvesting the future mortality (i.e. capturing natural drain). However, there are many questions related to tree growth responses and mortality across different site types that must still be addressed before commercial thinning can be implemented operationally across the landscape. Millar Western operationally thinned 32 plots between 1996 and 2003 and has been remeasuring them along with unthinned control plots every five years. The purpose of this work is to quantify and explain the tree growth response (both individual tree and stand level) to commercial thinning in mature lodgepole pine stands of different ages and on different site types. The forest sector directly employs over 200,000 people in Canada and contributes $23 billion to the national economy. This important industry relies on a sustainable supply of growing wood fibre which is at risk of decreasing. Enhanced forest management practices, such as commercial thinning, offer a potential solution to this issue.