鼎湖山森林演替初期优势种马尾松的树干液流特征  

Sap flow characteristics of the dominant tree species Pinus massoniana at the pioneer succession stage in the Dinghushan Mountain

作　　者：许天云 黄健强 曾小平[1] 张宜辉 孟泽[1] Dennis Otieno 李跃林[1] XU Tianyun;HUANG Jianqiang;ZENG Xiaoping;ZHANG Yihui;MENG Ze;Dennis Otieno;LI Yuelin(South China Botanical Garden,Chinese Academy of Sciences,Guangzhou 510650,China;College of Environment and Ecology,Xiamen University,Xiamen 361005,China;University of Chinese Academy of Sciences,Beijing 100049,China;Jaramogi Oginga Odinga University of Science and Technology,Bondo 210-40601,Kenya)

机构地区：[1]中国科学院华南植物园,广州510650 [2]厦门大学环境与生态学院,厦门361005 [3]中国科学院大学,北京100049 [4]肯尼亚奥丁加科技大学,邦多210-40601

出　　处：《应用与环境生物学报》2022年第5期1167-1174,共8页Chinese Journal of Applied and Environmental Biology

基　　金：国家自然科学基金项目(31961143023、31670453、41430529);中国科学院大学生创新实践训练计划资助。

摘　　要：采用Granier热消散探针法(thermal dissipation probes,TDP),对鼎湖山南亚热带森林演替初期优势树种马尾松(Pinus massoniana)的树干液流变化进行连续监测,同时监测林分光合有效辐射、空气相对湿度、空气温度等环境因子,以探究演替初期马尾松树干液流特征、耗水量与其对环境的响应.结果表明:(1)日尺度上针叶林马尾松不同个体树干液流日变化趋势一致,晴天日变化为典型昼高夜低的单峰型曲线,峰值一般出现在中午12:00-14:00;雨天树干液流日变化呈单峰或多峰趋势,液流速率显著低于晴天,峰值出现在降雨后1-2 h内.在干季与湿季,马尾松的液流速率在各方面存在显著差异,干季(10月)马尾松的夜间液流速率显著小于湿季(8月)(P <0.01),同时湿季(8月)峰值滞后于干季(10月)约90 min.(2)马尾松整树日均蒸腾耗水为56.25 kg/d,蒸腾耗水随着胸径的增大而增大,估算得到马尾松林日均蒸腾耗水为5 415 kg d^(-1)hm^(-2).(3)马尾松树干液流变化受中雨及以上降雨量影响,但低降雨量如小雨对树干液流特征无显著影响(P> 0.05).日尺度上针叶林马尾松晴天树干液流主要受光合有效辐射、水汽压亏缺的影响(P <0.01);雨天主要受水汽压亏缺、相对湿度、温度的影响.在湿季(8月)与干季(10月)日尺度上马尾松的树干液流特征均首要受到水汽压亏缺的调控.本研究的马尾松林处于演替初期,其优势种马尾松蒸腾量高于同地带演替中期的马尾松,但相比其他地区针叶林,该演替初期马尾松蒸腾量处于较低水平,这有利于其适应季节性干旱环境.Using Granier’s thermal dissipation technique, we measured the daily sap flow of the dominant tree species Pinus manssoniana in a coniferous forest at pioneer(or early) successional stages in the Dinghushan Reserve of southern China from August to October 2019. Environmental variables such as photosynthetically active radiation(PAR), air temperature(T), and relative air humidity(RH) were monitored to explore sap flow,water consumption, and their response to the environment in the early succession of P. massoniana. The results showed that the diurnal patterns of the sap flow of P. massoniana in different individuals were similar.On sunny days, the diurnal changes in sap flow velocity showed a typical single-peak curve, with maximum rates occurring between 12:00 and 2:00 p.m. On rainy days, single peak or multi-peak curves were significantly lower than on sunny days, and the peak occurred within a 1-2-hour lag after the end of the rainfall. The sap flow velocity during the dry season is significantly different from that during the wet season in many ways. The results showed that the sap flow velocity of P. manssoniana at night in the dry season(October) was significantly lower than that in the wet season(August)(P < 0.01), and the peak occurred(August) with a 90-min lag in the wet season compared to the dry season(October). In addition, the average daily transpiration water consumption of the whole P. massoniana tree was 56.25 kg/d, which increased its DBH. The average daily transpiration water consumption of the P. massoniana forest was estimated to be 5 415 kg d^(-1)hm^(-2). The sap flow of P. manssoniana was affected by rainfall;however, low rainfall had no significant effect on sap flow(P > 0.05). On a daily scale,PAR and vapor pressure deficit(VPD) were the two main environmental factors determining sap flow on sunny days(P < 0.01). In contrast, vapor pressure deficit(VPD), RH, and T are the main environmental factors determining tree transpiration on rainy days. The sap flow characteristics of P. mansoniana

关 键 词：马尾松 针叶林 演替初期 树干液流 鼎湖山 

分 类 号：S715.2[农业科学—林学]