Under climate change, modifications on plants’ growth are expected to be the strongest at species margins. Therein, tree acclimation could play a key role as migration is predicted to be too slow to track shifts of bioclimatic envelops. A requirement is, however, that intra-population genetic diversity be high enough for allowing such adaptation of tree populations to climate change. In this study, we tested for the existence of relationships between genetic diversity, site environmental conditions, and the response of annual tree growth to climate of Pinus cembra at its southern limit in the Alps. Site-specific climatic and environmental factors predominantly determined the response of trees along the precipitation gradient. The growth-climate interactions were chiefly linked to mean annual precipitation and temperature, slope and tree-size, and less to genetic diversity. We show that genetic background of Pinus cembra has exclusively indirect modulating power with limited effects on tree-ring formation, and within the southern limit in the Alps, genetic variability is not necessarily well expressed in the patterns of annual tree growth. Our results may imply little adaptive capacity of these populations to future changes in the water balance.

在气候变化下，植物生长的改变预计在物种边缘最为强烈。其中，树木适应可能发挥关键作用，因为预计迁移速度太慢，无法追踪生物气候包络的变化。然而，一个要求是种群内遗传多样性足够高，以允许树木种群适应气候变化。在这项研究中，我们测试了遗传多样性、立地环境条件以及每年树木生长对松树气候的响应之间是否存在关系。在阿尔卑斯山的南部边界。特定地点的气候和环境因素主要决定了树木沿降水梯度的响应。生长-气候相互作用主要与年平均降水量和温度、坡度和树木大小有关，与遗传多样性无关。我们表明，松树的遗传背景仅具有间接调节能力，对年轮形成的影响有限，并且在阿尔卑斯山的南部边界内，遗传变异不一定在年度树木生长模式中得到很好的表达。我们的结果可能意味着这些种群对未来水平衡变化的适应能力很小。