Quercus mongolica and Phellodendron amurense are two important broad-leaved species in temperate forests of Northeast China. It is critical to explore their responses to climate change for supporting management, protection, and restoration of the broad-leaved forest in Northeast China under the future climate change scenario. Three sampling sites along a longitude gradient, Heilun, Tieli and Yichun, were set up in the Xiaoxing'an Mountains. Dendrochronological methods were used to establish standard chronologies for Q. mongolica and P. amurense. Correlation analyses were conducted between these chronologies and local climatic factors to establish the spatial and temporal variations in growth-climate relationship of Q. mongolica and P. amurense. The results showed that the radial growth of P. amurense was sensitive to temperature, while that of Q. mongolica was limi-ted by both temperature and precipitation. The temperature sensitivities of these two species were different. High spring temperature inhibited the radial growth of Q. mongolica, but promoted that of P. amurense. The limiting effect of high maximum temperature in summer on radial growth of Q. mongolica was significantly higher than that of P. amurense. With the increases of longitude (water availability), the correlation coefficients between radial growth of Q. mongolica and precipitation gradually weakened, while P. amurense didn't change. The physiological characteristics of those tree species was the key factors affecting their growth-climate relationship. With the significant warming since the 1976, the growth trend of P. amurense increased, whilst that of Q. mongolica decreased. Deteriorated drought stress caused by warming and difference in the species' ability to cope with water deficits might be the main reasons for different responses of two species, and for the divergence phenomenon occurring for Q. mongolica. If warming continues or worsens in the future, the growth of Q. mongolica may decline due to the intensified drought stress, while that of P. amurense may be less affected or be slightly enhanced.
蒙古栎和黄菠萝是东北温带森林中重要的阔叶树种,探究二者对气候变化的响应关系能够为未来气候变化情境下东北阔叶林的经营、保护及恢复提供科学依据.本文在小兴安岭地区沿经度梯度设置3个采样点--海伦、铁力和伊春,运用树轮年代学方法建立了3个采样点蒙古栎和黄菠萝的标准年表,分析了其与当地气候因子的关系,揭示了蒙古栎和黄菠萝生长-气候关系的时空变异规律.结果表明: 研究区黄菠萝径向生长对生长季温度变化敏感,而蒙古栎径向生长受生长季温度和降水的共同限制作用.蒙古栎和黄菠萝对温度的响应存在差异: 春季均温升高抑制蒙古栎径向生长,而促进黄菠萝径向生长;夏季高温对蒙古栎径向生长的限制作用明显高于黄菠萝.随经度(水分)增加,蒙古栎径向生长与水分因子的关系逐渐减弱,而黄菠萝没有明显变化.树种生理特性是影响树木生长-气候关系的关键因素.1976年升温后,黄菠萝生长随温度升高而升高,但蒙古栎生长却随温度升高而呈下降趋势.升温造成的干旱胁迫可能是两树种生长响应差异及蒙古栎出现响应分异现象的重要原因.如果未来增温趋势持续或者加重,蒙古栎的生长可能会因干旱胁迫加剧而衰退,黄菠萝则不受影响或生长略微加快.
Keywords: Phellodendron amurense; Quercus mongolica; climate warming; radial growth; spatial and temporal variability; tree ring.