Microcoring and dendrometer-detected intra-annual wood formation of Populus euphratica in the Ejina Oasis,northwestern China  

作　　者：XiaoMei Peng ShengChun Xiao GuoDong Cheng QuanYan Tian HongLang Xiao 

机构地区：[1]Key Laboratory ofEcohydrology of Inland River Basin,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China [2]University of the Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Research in Cold and Arid Regions》2017年第1期54-66,共13页寒旱区科学（英文版）

基　　金：supported by the National Key Research and Development Program of China(2016YFC0501001);National Natural Science Foundation of China(No.91125026,No.41471082);the STS project of the Chinese Academy of Sciences(KFJ-EW-STS-00502)

摘　　要：Seasonal stem radial growth and wood formation of trees have become research hotspots because of their significance for dendroclimatological and dendroecological studies. However, until recently, these studies concentrated on coniferous tree species in high-altitude and high-latitude regions,while detailed information on arid-zone riparian forests is scarce. The main focus of this study is to monitor the intra-annual dynamics of radial growth and tree ring formation in a deciduous species, Populus euphratica. In 2013, we combined the dendrometer and microcoring methods to study this species in the riparian forest of the Ejina Oasis, in arid northwestern China. Vessel enlargement began in early May, and the maximum rate of cell production occurred in early June. The cell division then ceased from early to mid-July. The dendrometer method failed to reliably detect the date of growth initiation and cessation, but succeeded to detect the time of maximum growth rate just like the microcoring method did. We found that weekly stem radial increment data described xylem growth more accurately than daily datasets. Based on correlation analysis among climatic and hydrologic variables, and weekly stem radial increment, weekly ring width increase dataset, the depth to groundwater was the main factor that limited tree ring growth. From a practical perspective, such studies of intra-annual wood formation can provide empirical guidance for seasonal water allocations within a river basin.Seasonal stem radial growth and wood formation of trees have become research hotspots because of their significance for dendroclimatological and dendroecological studies. However, until recently, these studies concentrated on coniferous tree species in high-altitude and high-latitude regions,while detailed information on arid-zone riparian forests is scarce. The main focus of this study is to monitor the intra-annual dynamics of radial growth and tree ring formation in a deciduous species, Populus euphratica. In 2013, we combined the dendrometer and microcoring methods to study this species in the riparian forest of the Ejina Oasis, in arid northwestern China. Vessel enlargement began in early May, and the maximum rate of cell production occurred in early June. The cell division then ceased from early to mid-July. The dendrometer method failed to reliably detect the date of growth initiation and cessation, but succeeded to detect the time of maximum growth rate just like the microcoring method did. We found that weekly stem radial increment data described xylem growth more accurately than daily datasets. Based on correlation analysis among climatic and hydrologic variables, and weekly stem radial increment, weekly ring width increase dataset, the depth to groundwater was the main factor that limited tree ring growth. From a practical perspective, such studies of intra-annual wood formation can provide empirical guidance for seasonal water allocations within a river basin.

关 键 词：stem radial growth xylem growth CLIMATE groundwater depth riparian forest Heihe River northwestern China 

分 类 号：S792.11[农业科学—林木遗传育种]