坝上地区退化小叶杨树干液流特征及对环境因子的响应  

Characteristics of sap flow of degraded Populus simonii in Bashang Area,Hebei Province of northern China and its response to environmental factors

作　　者：杨东烨 余新晓[1] 李旭红 蒋涛 贾国栋[1] Yang Dongye;Yu Xinxiao;Li Xuhong;Jiang Tao;Jia Guodong(School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Huadong Engineering Corporation Limited,Hangzhou 311100,Zhejiang,China)

机构地区：[1]北京林业大学水土保持学院,北京100083 [2]中国电建集团华东勘测设计研究院有限公司,浙江杭州311100

出　　处：《北京林业大学学报》2024年第7期36-43,共8页Journal of Beijing Forestry University

基　　金：国家重点研发计划(2022YFF1302502-03);国家自然科学基金项目(42230714、U2243202)。

摘　　要：【目的】探究华北坝上地区退化和未退化小叶杨蒸腾耗水规律,合理配置生态用水,为小叶杨退化林的修复与重建提供理论参考。【方法】选取未退化、退化小叶杨为研究对象,利用热扩散探针(TDP)测定树干液流量,同时监测气象因子,研究两种小叶杨在不同天气下树干液流特征及其对环境因子的响应机制,分析生长旺季(7、8、9月)两种小叶杨树干液流与蒸腾量。【结果】(1)在不同天气条件下,退化和未退化小叶杨晴天树干液流速率大于雨天与阴天,晴天时两者差距最大,且未退化小叶杨树干液流的启动时间总是早于退化小叶杨;(2)生长季内两种小叶杨树干液流速率差异显著,未退化小叶杨蒸腾耗水量是退化小叶杨的3倍;(3)大气温度和光合有效辐射是影响小叶杨树干液流最主要的环境因子,未退化小叶杨对环境因子响应更敏感。【结论】退化小叶杨较低的蒸腾量难以维持正常生理所需,导致生理衰退,对环境因子变化的敏感性增加,进一步削弱了其应对未来干旱事件的能力。建议对已经发生退化的杨树林分进行更新改造。[Objective]This paper explores the transpiration water consumption patterns of degraded and undegraded Populus simonii in the Bashang Area,Hebei Province of northern China,optimizes the allocation of ecological water use,so as to provide theoretical references for the restoration and reconstruction of degraded Populus simonii forests.[Method]In this study,we selected undegraded and degraded Populus simonii as the research objects and used the thermal dissipation probe(TDP)method to determine the sap flow,and also monitored the meteorological factors to study sap flow characteristics of the two types of Populus simonii and their response mechanisms to environmental factors,as well as their sap flow and transpiration rates during the growing season(July,August and September).[Result](1)The relationship between daily changes of sap flow of degraded and undegraded Populus simonii was greater in sunny weather compared with rainy and cloudy days,with the largest difference observed on sunny days,and the initiation of sap flow of undegraded Populus simonii was always earlier than that of degraded Populus simonii.(2)The transpiration water consumption of undegraded Populus simonii was the highest during the growing season,and there was a significant difference in sap flow rates between the two species,with a 3 times difference in transpiration.(3)Temperature and photosynthetically active radiation(PAR)were the most important environmental factors affecting sap flow in Populus simonii,and undegraded Populus simonii was more sensitive to environmental factors.[Conclusion]The low transpiration of degraded Populus simonii makes it difficult to obtain the water required to maintain normal physiology,resulting in physiological decline,and its sensitivity to changes in environmental factors is increased,which further weakens its ability to cope with future drought events.Therefore,it is recommended to renovate the degraded poplar stand.

关 键 词：小叶杨 树干液流 退化 环境因子 

分 类 号：S774[农业科学—森林工程] S157[农业科学—林学]