高浓度O_3对银杏凋落叶化学组成的影响  

Effects of elevated O_3 concentration on chemical composition of leaf litter of Ginkgo biloba

作　　者：苏丽丽[1] 付伟[1,2] 徐胜 何兴元[1] 陈玮[1] 赵诣[1] 黄彦青[1] 

机构地区：[1]森林与土壤生态国家重点实验室中国科学院沈阳应用生态研究所,沈阳110016 [2]西南林业大学园林学院,云南昆明650224

出　　处：《生态学杂志》2015年第10期2757-2763,共7页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(31270518和31170573);国家科技支撑项目(2012BAC05B00);国家"水体污染控制与治理"专项(2012ZX07202-008)资助

摘　　要：北半球近地大气O3浓度在最近几十年里持续升高,对陆地生态系统产生深远的影响。本文选取5年生银杏(Ginkgo biloba)为研究对象,利用开顶式气室(OTCs)开展了3个不同浓度的O3(自然对照浓度约40 nmol·mol-1、处理浓度80和120 nmol·mol-1)熏蒸试验,持续熏蒸2个生长季(2012—2013年)后,于2013年11年月初收集其凋落叶,测定并分析不同处理下银杏凋落叶化学成分的变化。结果表明:与对照相比,高浓度O3处理组银杏凋落叶的N、K含量均显著升高,总酚含量以及C/N、木质素/N降低;而C、P、木质素含量以及C/P并未呈现出显著差异。可溶性糖、缩合单宁含量在两高浓度O3处理下变化趋势并不一致:与对照相比,可溶性糖含量仅在120 nmol·mol-1处理下表现出显著差异,降低38%;缩合单宁含量在80 nmol·mol-1处理下显著升高(343%),而在120 nmol·mol-1处理下无显著变化。木本植物凋落物的化学组成在O3熏蒸下会发生一定变化,这种变化可能会对树木凋落物在O3污染地区的分解及区域气候变化下森林生态系统的物质循环,特别是碳循环产生重要影响。Concentrations of ozone （03 ） near ground level in the northern hemisphere have increased substantially in the past few decades. Currently, the effects of elevated 03 concentration on the litter of woody plants were poorly investigated, particularly in China. In order to reveal the effects of elevatedO3 concentration on the chemical composition of leaf litter of G. biloba and forecast subsequent decomposition, an experiment was conducted to study the variations of the chemical composition in leaf litter of G. biloba exposed to elevated O3 concentrations （ 80 and 120 nmol. mol-1） during two successive growing seasons （2012- 2013 ） in open top chambers （OTCs）. The results showed that elevated O3 significantly increased N and K contents, while sig- nificantly reduced the content of total phenolics and the ratios of C/N and lignin/N. The contents of C, P, and lignin and the ratio of C/P of leaf litter from the elevated O3 treatments were not significantly different from those of the control. Elevated 03（ 120 nmol . mol-1） significantly de- creased the content of soluble sugar by 38%. The content of condensed tannins significantly in- creased by 343% under 80 nmol . mol-1 O3, while no significant change was found under 120 nmol . mol-1 O3 compared to the control. Different O3 concentrations caused different changes in chemical composition of leaf litter of G. biloba. We inferred that such variations of litter chemical composition might affect the decomposition of leaf litter and material cycling （ especially C） in forest ecosystems in O3-polluted areas.

关 键 词：臭氧 银杏 凋落叶 化学组成 

分 类 号：S792.95[农业科学—林木遗传育种]