不同时间尺度下落叶松液流速率与森林小气候的关系  

Relationship between sap flow velocity of Larix principis-rupprechtii and forest microclimate in different time scales

作　　者：任启文[1,2] 张岩 李联地[1,2] 尤海舟 毕君[1,2] REN Qiwen;ZHANG Yan;LI Liandi;YOU Haizhou;BI Jun(Hebei Academy of Forestry Science, Shijiazhuang 050061, Hebei, China;Hebei Xiaowutai Forestry Ecosystem Research Station, Zhuolu 075600, Hebei, China)

机构地区：[1]河北省林业科学研究院,河北石家庄050061 [2]河北小五台山森林生态系统定位研究站,河北涿鹿075600

出　　处：《中南林业科技大学学报》2018年第12期30-37,44,共9页Journal of Central South University of Forestry & Technology

基　　金：河北省林业科学技术研究项目(1801500);河北省林业科学技术研究项目(1701484);河北省重点研发计划项目(18226815D)

摘　　要：依据组织热平衡原理,运用热扩散探针法,于2016年4月1日—2017年4月1日对冀北山地小五台自然保护区华北落叶松的树干液流速率进行连续监测,并同步观测样地内森林梯度塔的分层环境因子,研究其树干液流特征与环境因子的关系。结果表明:(1)小时尺度上,在空气温湿度、水汽压亏缺及风速的分层因子中,落叶松树干液流速率与T_(a8.2 m)、RH_(8.2 m)、VPD_(8.2 m)相关性最好,与S_(14 m)相关关系最为密切。在土壤温度分层因子中,与浅层土壤温度(T_(s5 cm)～T_(s10 cm))显著正相关,与中层以下土壤温度(T_(s20 cm)～T_(s80 cm))相关关系不显著;在土壤含水量分层因子中,与浅中层土壤含水量(SWC_(5 cm)～SWC_(40 cm))相关关系不显著,与深层土壤含水量(SWC_(80 cm))显著正相关。在3种辐射中与紫外辐射UVR的相关系数最大,UVR中与UVA的相关系数明显大于UVB。在所有因子中与SD相关系数最大,呈极显著正相关。(2)随着时间尺度的扩大,温度对落叶松树干液流速率的影响有从地上逐渐转移到地下的趋势;空气相对湿度对落叶松树干液流速率的影响表现出先降后升的趋势;NR、TR、UVR、UVA、UVB、VPD、SD与落叶松液流速率的相关关系呈现逐渐降低的趋势。(3)考虑各环境因子对落叶松树干液流速率的综合影响,在小时尺度下影响最大的为SD和VPD_(8.2 m);在日尺度下影响最大的为UVR和SWC_(80 cm);在月尺度下影响最大的为T_(s20 cm),土壤因子的影响显著增加。3种尺度下的逐步回归方程,以月尺度下的决定系数最大,所需因子最少。Based on tissue heat balance theory,thermal dissipation sap flow velocity probes(TDPs)were used to measure sap flow velocity of Larix principis-rupprechtii at Xiaowutai natural reserve in northern mountain areas of Hebei province.To research relationship of the sap flow with the environmental factors,the stratified environmental factors in the sample plots were observed simultaneously from April,2016to April,2017.The results showed:(1)On the hourly scale,the sap flow velocity of Larix principisrupprechtii had the best correlation with Ta8.2m,RH8.2m,VPD8.2m and had closely relationship with S14m.As for the soil temperature,sap flow velocity had significantly positive correlation with the shallow soil temperature(Ts5cm^Ts10cm),and had no significant correlation with the soil temperature below the middle soil(Ts20cm^Ts80cm).The sap flow velocity had no significant correlation with the soil water content of shallow and middle soil(SWC5cm^SWC40cm),and had significantly positive correlation with the soil water content in deep soil(SWC80cm).The sap flow velocity had the largest correlation coefficient with UVR in three kinds of radiation,and the correlation coefficient with UVA was obviously greater than that of UVB.In the all environmental factors,the sap flow velocity had the maximum correlation coefficient with the SD,and showed the significant positive correlation.(2)With the expansion of time scale,the influence of temperature on stem sap flow velocity was gradually transferred from the overground to the underground.The influence of air relative humidity on the sap flow velocity showed a trend of firstly decreasing and then increasing.The correlation of NR,TR,UVR,UVA,UVB,VPD,SD with the sap flow velocity was gradually reduced.(3)Considering the comprehensive influence of environmental factors on sap flow velocity of Larix principis-rupprechtii,the influence of SD and VPD8.2m was the most on the hourly scale.On the daily scale,the influence of UVR and SWC80cm was the most.On monthly scale,the influence of Ts20cm was

关 键 词：华北落叶松 树干液流 环境因子 森林小气候 时间尺度 

分 类 号：S718.43[农业科学—林学]