Activity maintenance of the excised branches and a case study of NO_2 exchange between the atmosphere and P.nigra branches

作     者：Chun Chen Yuzheng Wang Yuanyuan Zhang Xiaoxiu Lun Chengtang Liu Yujing Mu Chenglong Zhang Pengfei Liu Chaoyang Xue Min Song Can Ye Junfeng Liu 

作者机构：Research Center for Eco-Environmental Sciences Chinese Academy of Sciences University of Chinese Academy of Sciences Center for Excellence in Urban Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences College of Environmental Science & Engineering Beijing Forest University 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2019年第31卷第6期

页      面：316-326页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 09[农学] 0903[农学-农业资源与环境] 090302[农学-植物营养学] 

基　　金：supported by projects of the National Key Research and Development of China (No. 2017YFC0209700) the National Natural Science Foundation of China (Nos. 41575121, 91544211, 41727805, 21477142) 

主　　题：Excised branches Activity maintenance NO2 exchange flux Hydroponics Dynamic chamber 

摘      要：The efficient maintenance of the activity of excised branches is the powerful guarantee to accurately determine gas exchange flux between the detached branches of tall trees and the atmosphere. In this study, the net photosynthetic rate(NPR) of the excised branches and branches in situ were measured simultaneously by using two photosynthetic instruments to characterize the activity of the excised branches of Phyllostachys nigra. The ratio of normalized NPR of excised branches to NPR in situ was used to assess the photosynthetic activity of detached branches. Based on photosynthetic activity, an optimal hydroponics protocol for maintaining activity of excised P. nigra branches was presented:1/8 times the concentration of Gamborg B5 vitamin mixture with p H = 6. Under the best cultivation protocol, photosynthetic activity of excised P. nigra branches could be maintained more than 90% within 6 hr in the light intensity range of 200–2000 μmol/(m2·sec) and temperature range of 13.4–28.7°C. The nitrogen dioxide(NO2) flux differences between in situ and in vitro branches and the atmosphere were compared using double dynamic chambers.Based on the maintenance method of excised branches, the NO2 exchange flux between the excised P. nigra branches and the atmosphere(from-1.01 to-2.72 nmol/(m2·sec) was basically consistent with between the branches in situ and the atmosphere(from-1.12 to-3.16 nmol/(m2 sec)) within 6 hr. Therefore, this study provided a feasible protocol for in vitro measurement of gas exchange between tall trees and the atmosphere for a period of time.