School of Forest Resources, Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Ecol Appl. 2012 Jan;22(1):154-65. doi: 10.1890/11-0150.1.
Projected climate change will affect existing forests, as substantial changes are predicted to occur during their life spans. Species that have ample intraspecific genetic differentiation, such as Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), are expected to display population-specific growth responses to climate change. Using a mixed-effects modeling approach, we describe three-year height (HT) growth response to changes in climate of interior Douglas-fir populations. We incorporate climate information at the population level, yielding a model that is specific to both species and population. We use data from provenance tests from previous studies that comprised 236 populations from Idaho, Montana, and eastern Washington, USA. The most sensitive indicator of climate was the mean temperature of the coldest month. Population maximum HT and HT growth response to changes in climate were dependent on seed source climate. All populations had optimum HT growth when transferred to climates with warmer winters; those originating in sites with the warmest winters were taller across sites and had highest HT growth at transfer distances closest to zero; those from colder climates were shortest and had optimum HT growth when transferred the farthest. Although this differential response damped the height growth differences among populations, cold-climate populations still achieved their maximum growth at lower temperatures than warm-climate populations. The results highlight the relevance of understanding climate change impacts at the population level, particularly in a species with ample genetic variation among populations.
预计气候变化将影响现有的森林，因为在其生命周期内预计会发生重大变化。具有充足种内遗传分化的物种，如道格拉斯冷杉（Pseudotsuga menziesii (Mirb.) Franco），预计将表现出对气候变化的特定种群生长反应。我们使用混合效应建模方法，描述了内陆道格拉斯冷杉种群三年来对气候变化的高度（HT）生长反应。我们在种群水平上纳入气候信息，得出了一种特定于物种和种群的模型。我们使用来自先前研究的种源试验的数据，这些研究包括来自美国爱达荷州、蒙大拿州和华盛顿东部的 236 个种群。最敏感的气候指标是最冷月的平均温度。种群最大 HT 和 HT 对气候变化的生长反应取决于种子源气候。所有种群在转移到冬季温暖的气候时都有最佳的 HT 生长；那些起源于最温暖冬季的种群在各个地点都更高，在最接近零的转移距离处的 HT 生长最高；那些来自较冷气候的种群最短，在最远的转移距离时具有最佳的 HT 生长。尽管这种差异反应减弱了种群间的高度生长差异，但冷气候种群在较低的温度下仍能达到最大生长。研究结果强调了在种群水平上理解气候变化影响的相关性，特别是在具有充足种群间遗传变异的物种中。
