Plant size,environmental factors and functional traits jointly shape the stem radius growth rate in an evergreen coniferous species across ontogenetic stages  

植物个体大小、环境和功能性状共同决定了常绿针叶植物个体发育阶段的径向生长率

作　　者：Zhili Liu Kouki Hikosaka Fengri Li Liangjun Zhu Guangze Jin 

机构地区：[1]Center for Ecological Research,Northeast Forestry University,Harbin 150040,China [2]Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education,Northeast Forestry University,Harbin 150040,China [3]Graduate School of Life Sciences,Tohoku University,Sendai,Miyagi 980-8578,Japan [4]School of Forestry,Northeast Forestry University,Harbin 150040,China [5]National Engineering Laboratory for Applied Technology of Forestry&Ecology in South China,College of Life Science and Technology,Central South University of Forestry and Technology,Changsha 410004,China

出　　处：《Journal of Plant Ecology》2021年第2期257-269,共13页植物生态学报（英文版）

基　　金：by the National Natural Science Foundation of China(31971636,31870399);Yong Elite Scientists Sponsorship Program by CAST(2018QNRC001).

摘　　要：Aims Plant size,environmental conditions and functional traits are important for plant growth;however,it is less clear which combination of these factors is the most effective for predicting tree growth across ontogenetic stages.Methods We selected 65 individuals of an evergreen coniferous species,Pinus koraiensis,with diameters at breast height(DBH)from 0.3 to 100 cm in Northeast China.For each individual,we measured the stem radius growth rate(SRGR,µm/year)for the current year,environmental factors(light,soil nutrient and soil water)and functional traits(leaf,branch and root traits).Important Findings SRGR increased with DBH when the DBH was lower than 58 cm,whereas it decreased with DBH when the DBH was larger than 58 cm.Structural equation modeling analysis suggested that,when the DBH was 0–15 cm,plant size had a direct negative influence on SRGR and an indirect positive influence on SRGR due to the light intensity above the plant.Plant size had direct positive and negative effects when the DBH was 16–58 cm and 59–100 cm,respectively.When the DBH was larger than 15 cm,soil parameters were more important than light intensity for SRGR.The functional traits selected for use in the best model were changed from the specific leaf area and wood density to the root nitrogen concentration with increasing tree size.In summary,plant size,environmental factors and functional traits jointly shaped tree growth,and their relative influence varied with size,suggesting that the resources limiting tree growth may change from light to soil nutrient with increasing tree size.植株个体大小、环境及功能性状对于树木生长至关重要,然而在树木个体发育过程中其对树木生长的调控机制尚不清晰。本研究以中国东北常绿针叶树种红松(Pinus koraiensis)为研究对象,选择65株胸高直径(DBH)范围为0.3–100 cm的样树,测定当年的径向生长量、环境因素(光照、土壤养分和土壤水分)以及功能性状(叶、枝和根性状)。研究结果表明,径向生长率随DBH变化呈单峰模式,DBH为58 cm时达到峰值。结构方程模型的分析表明,当DBH<15 cm时,植株个体大小对径向生长存在直接的负影响,但通过增加光强而间接地促进其生长;当DBH为16–58 cm和59–100 cm时,植株大小对树木径向生长分别存在直接的正影响和负影响;当DBH<15 cm时,光照对径向生长的影响大于土壤因素,而当DBH>15 cm时,呈相反趋势;预测树木生长的最优性状随植株个体的增大依次由比叶面积转变为木质密度及细根氮含量。因此,植株个体大小、环境和功能性状共同驱动树木的径向生长,其相对影响随树木生长而变化,且树木径向生长的限制因素随树木生长由光照转变为土壤养分。

关 键 词：tree growth specific leaf area wood density root nitrogen concentration light intensity soil nutrient 

分 类 号：Q94[生物学—植物学]