Modeling mid-rotation growth and mortality in boreal mixedwoods

西部北方混交林区是一片4800万公顷的落叶针叶混交林，从落基山脉北部延伸到马尼托巴省西南部，面积约为艾伯塔省的75%。这一地区普遍的工业林管理是相对较新的。因此，到目前为止，支持可持续经营的监测方案遵循的是最受关注的林分；自25年前开始积极重新造林以来种植的幼林，以及即将收获的70年或更老的天然原始林。缺乏中龄(25-70年生)混交林和以年轻白云杉为主(70年生)林分的数据，阻碍了我们准确预测采伐或自然干扰后森林发展的能力。在林分发育中期，主要树种杨树和白云杉的生长和死亡速度及其相互影响的数量很少。这项提案中包括的研究将调查这些物种之间的相互作用。将利用树木年轮测量、历史上的白云杉释放试验和我们自己的目标监测小区。结果将被集成到森林生长的计算机模拟模型中，该模型评估这些因素的相对重要性，为森林规划提供工具，并支持干预决策(苗木选择、种植、抚育和间伐)，以有效地管理西部北方森林。

The western boreal mixedwood forest region is a 48 million hectare band of mixed deciduous-coniferous forest extending from the northern Rocky mountains to southwestern Manitoba, covering an area about 75% the size of Alberta. Widespread industrial forest management of this region is relatively recent. As a result, the monitoring programs which support sustainable management have so far followed the stands of most interest; the young stands which were planted since active reforestation efforts began 25 years ago, and the 70-year and older natural-origin stands which will soon be harvested. A lack of data for mid-aged (25-70 year old) mixed-species stands and younger white spruce dominated (<70 year old) stands is hindering our ability to accurately predict forest development following harvesting or natural disturbance. Rates of growth and mortality of the major species, aspen and white spruce, and their effects on each other during these middle years of stand development are poorly quantified. The studies included in this proposal will investigate these species interactions. Tree-ring measurements, a historical white spruce release trial, and our own targeted monitor plots will be utilized. Results will be integrated into a computer simulation model of forest-growth which evaluates the relative importance of these factors, provides a tool for forest planning, and supports intervention decisions (nursery stock selection, planting, tending, and thinning) for effective management of the western boreal forest.