Abstract

Tree diameter growth models for northern hardwoods commonly used large data sets representing a composite of stands with varying management histories, structural characteristics, and age distributions. Yet common predictor variables like diameter can show differences in growth patterns for stands with different age structures and management histories. To address that, we modeled growth and mortality for sugar maple, red maple, and yellow birch in thinned even-aged Adirondack northern hardwoods. Findings indicate that change in diameter depends on initial diameter for sugar maple, with the rate decreasing exponentially from the largest size class to the smallest. Initial diameter did not prove significant with red maple and yellow birch in these thinned stands, perhaps because of the limited sample of trees of small diameter. Stand relative density and time since treatment affected growth for all three species. Those variables also proved significant for predicting mortality of sugar maple. Analyses revealed fewer losses of sugar and red maples among the larger diameter classes, but no relationship with diameter for yellow birch. Plot relative density did not affect mortality with red maple, but time after thinning had a significant effect on survival of all species.

中文翻译：

---

均匀老化的阿迪朗达克北部硬木的糖枫，红枫和黄桦生长与死亡率

摘要

北方硬木的树木直径生长模型通常使用大数据集，这些数据集代表具有不同管理历史，结构特征和年龄分布的林分的组合。然而，常见的预测变量（例如直径）可以显示具有不同年龄结构和管理历史的林分的生长模式差异。为了解决这个问题，我们在稀薄的平均年龄的阿迪朗达克北部硬木中模拟了糖枫，红枫和黄桦的生长和死亡率。研究结果表明，直径的变化取决于糖枫的初始直径，比率从最大的尺寸类别到最小的尺寸呈指数下降。在这些稀疏的林分中，红枫和黄桦的初始直径没有明显的意义，这也许是因为小直径树木的样本有限。自从处理影响了这三个物种的生长以来，林分相对密度和时间。这些变量对于预测糖枫的死亡率也具有重要意义。分析显示，在较大直径类别中，糖和红枫的损失较少，但与黄桦直径无关。地块的相对密度不影响红枫的死亡率，但稀疏后的时间对所有物种的存活率都有显着影响。