[目的]分析影响华北土石山区侧柏水分利用的主导因子，为气候变化背景下中国侧柏人工林的经营管理提供参考。[方法]采用稳定碳同位素比值δ13C计算侧柏水分利用效率(intrinsic water use efficiency，WUEi)，结合温度、降雨量、相对湿度、干旱指数(standardized precipitation evapotranspiration index，SPEI)、水热状况协同性等气候指标，分析华北土石山区侧柏WUEi变化特征及其对气候变化的响应。[结果]侧柏树轮δ13C与WUEi均呈现上升趋势，年平均值分别为-23。53%和87。08 µmol·mol-1，年平均增幅分别为0。09%和1。17 µmol·mol-1。在月尺度上，侧柏WUEi与上年 7月、9-12月和当年 1-12月温度呈显著正相关，与上年 6-7月、12月和当年 1-12月SPEI呈显著负相关，与上年8月和当年3-5月、8月相对湿度呈显著负相关，除与上年12月降雨量呈显著负相关关系外，与其他各月降雨量均无显著关系。在年尺度上，WUEi与温度呈极显著正相关，与SPEI及相对湿度呈极显著负相关，与降雨量无显著关系。侧柏WUEi对温度和降雨量的敏感性在14。12～<15。04℃和545。97～<762。43 mm时达到最高，分别为17。87%和21。88%;当水热协同性在0。992～0。998时，WUEi对其敏感性为17。30%。[结论]温度是影响华北土石山区侧柏WUEi变化的最主要气候因子，随着温度与降雨量协同性的增强，侧柏WUEi对水热协同作用的敏感性呈升高趋势，降雨量间接影响侧柏WUEi。
Water use efficiency of platycladus orientalis and its response to climate factors in rocky mountainous areas of North China
[Objective]This study aims to analyze the dominant factors affecting the water use of Platy-cladus orientalis in the rocky mountainous areas of North China,and provide reference for the manage-ment of artificial Platycladus orientalis forests in China under the background of climate change.[Method]Using stable carbon isotope technology δ13C to calculate the intrinsic water use efficiency(WUEi),of Platycladus orientalis,combined with climate indicators such as average temperature,precipitation,relative humidity,standardized precipitation evapotranspiration index(SPEI),and the synergistic effect of water and heat,the variation characteristics of WUEi of Platycladus orientalis in the rocky mountainous areas of North China and its response to climate change were analyzed.[Result]The δ13C value and WUEi of Platycladus orientalis showed an upward trend,with an average annual increase of 0.09%and 1.17 µmol·mol-1,and an average annual value of-23.53%and 87.08 µmol·mol-1,respectively.On the monthly scale,the WUEi of Platycladus orientalis was significantly positively correlated with the temperature in July,September to December of the previous year,January to December of the current year,and significantly negatively correlated with the SPEI in June to July,December of the previous year,January to December of the current year,and significantly negatively correlated with the relative humidity in August of the previous year,March to May,and August of the current year;Except for a significant negative correlation with the precipitation in December of the previous year,there was no significant correlation with the precipitation in other months.On the annual scale,WUEi was signifi-cantly positively correlated with temperature,significantly negatively correlated with SPEI and relative humidity,and not significantly correlated with precipitation.The sensitivity of lateral cypress WUEi to temperature and precipitation reached its highest at 14.12-<15.04℃and 545.97-<762.43 mm,with values of 17.87%and 21.88%,respectively;When the water heat synergy was between 0.992 to 0.998,the sensitivity of WUEi to it was 17.30%.[Conclusion]Temperature was the main climate factor affecting the WUEi characteristics of Platycladus orientalis in the rocky mountainous areas of North China.With the enhancement of the synergy between temperature and precipitation,the WUEi of Platycladus orientalis sensitivity to the synergistic effect of water and heat showed an upward trend,and precipitation indirectly affected the WUEi characteristics of Platycladus orientalis.
Platycladus orientaliswater use efficiencyclimate factorstable carbon isotoperocky mountainous areas of North China
万方数据
维普
