The impact of climatic change on forest ecosystems has received considerable attention, but our understanding of the modulation of this impact by elevational differences and by species interaction is still limited. Here, we analyse tree-ring-based growth-climate relationships for two dominant tree species along an 800-m elevational gradient on Jeju Island, South Korea. Both species, broadleaf Quercus mongolica (QUMO) and coniferous Abies koreana (ABKO), grow at the southern end of their distributional range and they have adjacent altitudinal ranges. We use static and moving bootstrapped correlation analysis to identify the effect of recent warming on their growth. QUMO is primarily positively influenced by moisture during the previous autumn at its upper elevational distribution. Recent warming, however, has diminished this relationship, while the enhancing impact of warm and dry summer conditions on QUMO growth has increased. These recent shifts in growth-climate relationship suggest an upward migration potential for QUMO due to warming-enhanced growth at higher elevations. ABKO growth, on the contrary, is primarily reduced by high winter and summer temperatures. This negative relationship has become more explicit in recent decades, particularly at lower elevations. At the highest elevation, however, ABKO growth-temperature relationship has consistently become more positive in the most recent decades. In the elevational zone where ABKO and QUMO co-exist, warming plays a primary role in ABKO growth reduction, while QUMO growth increases and thus induces a potential upward migration of QUMO. This combined effect can lead to population decline of ABKO. Our results significantly enhance our understanding of the impact of climate warming on two interacting species and provide information necessary for adaptation strategies to preserve declining ABKO populations.

中文翻译：

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树木生长对东北亚两种地方性物种近期变暖的响应

气候变化对森林生态系统的影响受到了相当大的关注，但我们对海拔差异和物种相互作用对这种影响的调制的理解仍然有限。在这里，我们分析了韩国济州岛 800 米海拔梯度上两种主要树种的基于树轮的生长气候关系。阔叶栎属 (QUMO) 和针叶冷杉 (ABKO) 这两个物种都生长在其分布范围的南端，并且具有相邻的海拔范围。我们使用静态和移动自举相关分析来确定近期变暖对其增长的影响。QUMO 主要受前一个秋季在其高海拔​​分布的水分的积极影响。然而，最近的变暖削弱了这种关系，而温暖干燥的夏季条件对 QUMO 生长的增强影响有所增加。这些最近生长-气候关系的变化表明，由于高海拔地区的变暖促进了生长，QUMO 有向上迁移的潜力。相反，ABKO 的生长主要因冬季和夏季高温而减少。近几十年来，这种负面关系变得更加明显，尤其是在低海拔地区。然而，在最高海拔处，ABKO 生长-温度的关系在最近几十年里一直变得更加积极。在 ABKO 和 QUMO 共存的高地带，变暖在 ABKO 增长减少中起主要作用，而 QUMO 增长增加，从而诱导 QUMO 潜在的向上迁移。这种综合效应会导致 ABKO 的种群数量下降。