北京密云油松林下灌木小叶鼠李叶片资源利用效率季节变异及环境调控  

Seasonal Variation and Environmental Control of Leaf Resource Use Efficiencies of an Understory Shrub,Rhamnus parvifolia in Pinus tabuliformis Forest in Miyun,Beijing

作　　者：赵洪贤 苏同 王瑞福 孙艳丽 高永龙 隗骥超 李鑫豪 田赟[1,2] 贾昕 查天山[1,2] Zhao Hongxian;Su Tong;Wang Ruifu;Sun Yanli;Gao Yonglong;Wei Jichao;Li Xinhao;Tian Yun;Jia Xin;Zha Tianshan(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083;State Key Laboratory of Efficient Production of Forest Resources,Beijing 100083;Forestation Management Center of Huairou District,Beijing 101499;The Beijing Center for Forest Resource Planning and Monitoring,Beijing 100193;Beijing Lülin Shengyuan Greening Engineering Co.,Ltd.,Beijing 102400)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]林木资源高效生产全国重点实验室,北京100083 [3]怀柔区营林造林管护中心,北京101499 [4]北京市园林绿化规划和资源监测中心,北京100193 [5]北京绿林盛源绿化工程有限公司,北京102400

出　　处：《林业科学》2023年第7期1-11,共11页Scientia Silvae Sinicae

基　　金：国家重点研发计划(2020YFA0608100);北京园林绿化生态系统监测网络(GJH-2023-027)。

摘　　要：【目的】探究小叶鼠李叶片的光、氮、水资源利用效率(RUEs)在较长时间尺度(季节)上的变化特征,分析环境变化对RUEs季节动态的影响、叶片功能性状与RUEs的关系以及不同RUEs间的权衡关系。【方法】2021年6—10月,在北京密云山区,以当地林下优势灌木小叶鼠李为研究对象,对其光合参数和环境因子进行连续原位观测,使用LI-6800便携式光合测定仪测量小叶鼠李叶片光合光响应曲线的特征参数,同时测量其叶片功能性状,结合观测的环境因子数据,分析小叶鼠李叶片内禀水分利用效率(WUEi)、氮利用效率(NUE)和光利用效率(LUE)季节动态变化的影响因素及RUEs间的权衡关系。【结果】1)小叶鼠李在生长期内WUEi、NUE、LUE的最大值分别为107.3μmol·mol^(-1)、18.35μmol·g^(-1)s^(-1)、0.087 mol·mol^(-1),其季节变异系数(CV)分别为24.91%、39.12%、12.6%。2)在生长季中期,土壤相对可利用含水量充足的湿润条件下(REW>0.4),小叶鼠李具有较大的NUE和较小的WUEi,NUE与WUEi的变化趋势相反(P<0.05),与LUE变化趋势相同(P<0.05)。3)WUEi与比叶质量(LMA)正相关(P<0.05),与蒸腾速率(T_(r))负相关(P<0.05);而NUE与LMA和叶厚度(LT)负相关(P<0.05),与蒸腾速率(T_(r))正相关(P<0.05);空气温度(T_(a))、光合有效辐射(PAR)和散射辐射(R_(dif))增加均会促进增加叶片LUE(P<0.05)。【结论】在土壤湿润、光照条件受限的条件下,林下优势灌木小叶鼠李叶片的WUEi、NUE均与土壤含水量解耦,与比叶质量和蒸腾速率关系密切;辐射强度和空气温度增加均会提高叶片的光、氮利用效率,且散射辐射增加也能提高林下灌木的光合能力。小叶鼠李叶片不同RUEs之间存在权衡关系,在生长季内不会同时出现最大化的WUEi和NUE,在土壤湿润、光照减少的条件下,NUE与LUE变化趋势一致,均在生长季中期波动变化,生长季末期逐渐降低。【Objective】This study aims to clarify the trade-offs between light,nitrogen and water use efficiency(RUEs)in the leaves of the understorey shrub Rhamnus parvifolia and their environmental regulation mechanisms.【Method】We analyzed the seasonal dynamics of intrinsic water use efficiency(WUEi),nitrogen use efficiency(NUE)and light use efficiency(LUE)as well as the trade-offs among RUEs of a dominant understory shrub,R.parvifolia,leaves through season-long in-situ measurements of the light response curve and leaf functional traits along with simultaneous environmental measurements from June to October,2021 in Miyun,Beijing,China.【Result】1)The result showed that the maximum WUEi,NUE,and LUE in growing season fluctuated with values of 107.3μmol·mol^(−1),18.35μmol·g^(−1)s^(−1),and 0.087 mol·mol^(−1),respectively,with coefficient of variation(CV)being 24.91%,39.12%,and 12.6%.2)In the middle of the growing season,under the wet condition with relative extractable soil water(REW)greater than 0.4,there were higher NUE and lower WUEi.The NUE had opposite trend to WUEi(P<0.05)and varied synergistically with LUE(P<0.05).3)The WUEi was positively correlated with leaf mass per unit area(LMA)(P<0.05)and negatively correlated with transpiration rate(Tr,P<0.05),while NUE was negatively correlated with LMA and leaf thickness(LT,P<0.05)and positively correlated with Tr(P<0.05).Increases in air temperature(T_(a)),photosynthetically active radiation(PAR)and diffuse radiation(Rdif)all contributed to increased LUE(P<0.05).【Conclusion】It has been found that WUEi and NUE are decoupled from soil water content and closely relate to LMA and Tr in wet period and limited light.Increasing radiation and T_(a) promotes the light utilization efficiency of leaf,and diffuse radiation raises the photosynthetic capacity of leaf.There is a trade-off between RUEs.The NUE and WUEi can not simultaneously maximize in the growing season,but under wet condition and low light,NUE and LUE change in the same direction,both fluctuating

关 键 词：叶片功能性状 资源利用效率 光响应曲线 林下灌木 小叶鼠李 

分 类 号：S718.43[农业科学—林学]