Functional traits of poplar leaves and fine roots responses to ozone pollution under soil nitrogen addition  

作　　者：Pin Li Rongbin Yin Huimin Zhou Sheng Xu Zhaozhong Feng 

机构地区：[1]Research Center for Urban Forestry,Key Laboratory for Forest Silviculture and Conservation of Ministry of Education,Key Laboratory for Silviculture and Forest Ecosystem Research in Arid-and Semi-arid Region of State Forestry Administration,Beijing Forestry University,Beijing 100083,China [2]State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China [3]Key Laboratory of Forest Ecology and Management,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China [4]Institute of Ecology,Key Laboratory of Agrometeorology of Jiangsu Province,School of Applied Meteorology,Nanjing University of Information Science and Technology,Nanjing 210044,China

出　　处：《Journal of Environmental Sciences》2022年第3期118-131,共14页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos.31870458,41675153);the National Key Research and Development Program of China(No.2017YFE0127700).

摘　　要：Concurrent ground-level ozone(O_(3))pollution and anthropogenic nitrogen(N)deposition can markedly influence dynamics and productivity in forests.Most studies evaluating the functional traits responses of rapid-turnover organs to O_(3) have specifically examined leaves,despite fine roots are another major source of soil carbon and nutrient input in forest ecosystems.How elevated O_(3) levels impact fine root biomass and biochemistry remains to be resolved.This study was to assess poplar leaf and fine root biomass and biochemistry responses to five different levels of O_(3) pollution,while additionally examining whether four levels of soil N supplementation were sufficient to alter the impact of O_(3) on these two organs.Elevated O_(3) resulted in a more substantial reduction in fine root biomass than leafbiomass;relative to leaves,more biochemically-resistant components were present within fine root litter,which contained high concentrations of lignin,condensed tannins,and elevated C:N and lignin:N ratios that were associated with slower rates of litter decomposition.In contrast,leaves contained more labile components,including nonstructural carbohydrates and N,as well as a higher N:P ratio.Elevated O_(3) significantly reduced labile components and increased biochemically-resistant components in leaves,whereas they had minimal impact on fine root biochemistry.This suggests that O_(3) pollution has the potential to delay leaf litter decomposition and associated nutrient cycling.N addition largely failed to affect the impact of elevated O_(3) levels on leaves or fine root chemistry,suggesting that soil N supplementation is not a suitable approach to combating the impact of O_(3) pollution on key functional traits of poplars.These results indicate that the significant differences in the responses of leaves and fine roots to O_(3) pollution will result in marked changes in the relative belowground roles of these two litter sources within forest ecosystems,and such changes will independently of nitrogen load.

关 键 词：Ozone pollution Nitrogen(N)input Fine roots LEAVES Functional traits Chemical complexity 

分 类 号：X173[环境科学与工程—环境科学] X515