摘要
目前尚不清楚地表臭氧(O_(3))污染下植物、土壤和微生物之间的直接或间接相互作用对森林地上和地下固碳功能的影响。采用开顶式气室装置和结构方程模型,研究4种O_(3)浓度下欧美杨107(Populus euramericana cv.‘74/76’)的光合性状、叶和细根生化性状、土壤理化因子和土壤微生物群落特征对地上和地下生物量降低的直接和间接效应。结果表明,O_(3)浓度升高(86 nmol/mol)分别导致杨树地上、地下和总生物量相比对照分别下降16%、11%和15%,对地上生物量降低的影响大于地下生物量。结构方程模型发现光合速率、叶淀粉和叶非结构性碳水化合物对地上生物量有直接的影响;表明O_(3)主要通过影响植物的光合生理代谢过程对地上生物量积累产生直接作用。O_(3)对地下生物量的影响是通过直接影响叶氮和土壤总碳,叶氮再影响叶淀粉从而间接影响地下生物量。土壤pH、总碳和土壤微生物(细菌和真菌群落)对地上产生直接效应,且O_(3)对真菌群落的影响效应大于细菌群落,表明植物通过地下过程对O_(3)的响应可直接反馈作用于生物量的积累和分配过程。本研究通过解析植物、土壤和微生物之间的直接或间接相互作用为评估O_(3)污染对杨树人工林地上和地下固碳功能的影响提供科学依据。
Ozone(O_(3))pollution can alter carbon allocation and reduce tree growth-both above and below ground,but the effects of direct or indirect interactions among plants,soil and microorganisms under ground-level ozone(O_(3))pollution on above-and below-ground carbon sequestration of forests are not yet clear.Here,we used the open-top chamber device and structural equation model to explore the direct and indirect effects of photosynthetic characters(net photosynthetic rate[Pn],stomatal conductance[gs],intercellular CO2 concentration[Ci],transpiration rate[Tr],water use efficiency[WUE],excitation energy capture efficiency of PSII reaction center[Fv′/Fm′],actual photochemical efficiency of PSII in the light[PhiPS2],coefficient of photochemical quenching[qP],and apparent electron transport rate[ETR]),leaf and fine root biochemical characters(total carbon,nitrogen,and phosphorus levels,concentrations of non-structural carbohydrates(soluble sugar and starch),lignin,and condensed tannins),soil physicochemical factors(moisture,pH,total carbon,total nitrogen,total phosphorus,and exchangeable NH+4-N and NO-3-N levels)and phospholipid fatty acids-based soil microbial community characteristics on above-and below-ground biomass reduction of poplar 107(Populus euramericana cv.′74/76′)at four O_(3) concentrations(charcoal-filtered air,non-filtered air,non-filtered air+40 ppb of O_(3),and non-filtered air+60 ppb of O_(3)).The results showed that compared to CF,an increase in O_(3) concentration(86 nmol/mol)resulted in a 16%,11%,and 15%decrease in aboveground,belowground,and total biomass of poplar trees,respectively,with a greater impact on the reduction of aboveground biomass than belowground biomass.Elevated O_(3) concentration significantly decreased Pn,gs,Tr,WUE,Fv′/Fm′,PhiPS2,qP,and ETR while increased Ci.The increase of O_(3) concentration significantly increased the content of soluble sugar and tannin and decreased the content of starch,TNC and lignin in leaves while had no effects on the contents of C,N,soluble s
作者
吴贤杰
李品
闫香如
侯霄帆
WU Xianjie;LI Pin∗;YAN Xiangru;HOU Xiaofan(State Key Laboratory of Efficient Production of Forest Resources of Beijing Forestry University,The Key Laboratory for Silviculture and Conservation of Ministry of Education,Key Laboratory for Silviculture and Forest Ecosystem of State Forestry and Grassland Administration,Beijing 100083,China)
出处
《生态学报》
CAS
CSCD
北大核心
2024年第15期6684-6695,共12页
Acta Ecologica Sinica
基金
国家自然科学基金(32271673)
北京林业大学“5·5工程”科研创新团队项目(BLRC2023B06)。
