Modeling mid-rotation growth and mortality in boreal mixedwoods

西部北方混交林地区是一个4800万公顷的落叶针叶混交林带，从北方落基山脉延伸到马尼托巴西南部，覆盖面积约为阿尔伯塔的75%。这一地区的工业化森林管理是最近才广泛开展的。因此，支持可持续管理的监测方案迄今为止一直跟踪最感兴趣的林分;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年以上的天然林。缺乏中龄（25-70年）混种林分和较年轻的白色云杉占主导地位（<70年）的林分的数据，阻碍了我们准确预测采伐或自然干扰后森林发展的能力。主要树种，白杨和白色云杉的生长和死亡率，以及它们之间的相互影响，在这些中间年的林分发展是很难量化的。本提案中包含的研究将调查这些物种的相互作用。树木年轮测量，一个历史性的白色云杉释放试验，和我们自己的目标监测图将被利用。结果将被整合到一个计算机模拟模型的森林生长，评估这些因素的相对重要性，森林规划提供了一个工具，并支持干预决策（苗木选择，种植，抚育和间伐）的西部北方森林的有效管理。

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.