土壤氮添加对水曲柳和蒙古栎光合限制作用的影响  

Effects of soil nitrogen addition on photosynthetic limitations in Fraxinus mandshurica Rupr.and Quercus mongolica Fish.ex Ledeb

作　　者：朱凯 左齐慧 袁凤辉[3] 关德新[3] 吴家兵[3] 王安志[3] 张健[1] Zhu Kai;Zuo Qi-Hui;Yuan Feng-Hui;Guan De-Xin;Wu Jia-Bing;Wang An-Zhi;Zhang Jian(College of Resources&Environment of Shanxi Agricultural University,Taigu,Shanxi 030801,China;State Key Laboratory of Sustainable Dryland Agriculture(in preparation),Shanxi Agricultural University,Taiyuan 030031,China;State Key Laboratory of Forest and Soil Ecology,Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China;Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]山西农业大学资源环境学院,山西太谷030801 [2]山西农业大学资源环境学院,省部共建有机旱作农业国家重点实验室(筹),太原030031 [3]中国科学院沈阳应用生态研究所,中国科学院森林生态与管理重点实验室,沈阳110016 [4]中国科学院大学,北京100049

出　　处：《植物科学学报》2023年第4期502-512,共11页Plant Science Journal

基　　金：山西农业大学省部共建有机旱作农业国家重点实验室自主研发项目(202001-9);山西农业大学科技创新基金项目(2020BQ70);山西省博士毕业生、博士后研究人员来晋工作奖励资金科研项目(SXBYKY2021013);国家自然科学基金项目(41675112;31670707);山西省产教融合研究生联合培养示范基地建设项目(2022JD05)。

摘　　要：本文以试验地常年大气氮(N)沉降量(23 kg·ha^(−1)·year^(−1))为依据,设计了低度(LN,23 kg·ha^(−1)·year^(−1))、中度(MN,46 kg·ha^(−1)·year^(−1))和高度(HN,69 kg·ha^(−1)·year^(−1))3种氮添加水平以模拟大气氮沉降,以无氮添加处理为对照(CK),探究过度氮沉降对森林阔叶树种水曲柳(Fraxinus mandshurica Rupr.)和蒙古栎(Quercus mongolica Fish.ex Ledeb)的生理生态效应。结果显示:(1)两树种CO_(2)扩散性限制作用(即气孔限制lsc和叶肉限制lm)在氮添加后减弱,而后随氮量的增加先减弱后增强;其生化限制lb则在氮添加后增强,后随氮量增加先增强后减弱;(2)3种光合限制作用均在MN下达到最值,中度土壤氮添加量对植株光合的促进效应最高;(3)土壤氮添加期间植株光合能力的增强主要源于CO_(2)扩散性限制作用的减弱,而gsc变化(即lsc)为扩散性限制的主角作用因子;(4)3种光合限制作用(lsc、lm和lb)在不同生长期(7月和8月)均未表现出显著差异,表明lsc的光合主角限制“角色”无季节性差异;(5)一定范围内的土壤氮添加不会对植株的水分利用潜力产生显著影响。Based on natural nitrogen deposition in the field(23 kg·ha^(−1)·year^(−1)),this research employed low(LN,23 kg·ha^(−1)·year^(−1)),moderate(MN,46 kg·ha^(−1)·year^(−1)),and high(HN,69 kg·ha^(−1)·year^(−1))nitrogen levels to simulate natural nitrogen deposition,using no nitrogen addition used as a control(CK).The goal was to ex-plore the physiological and ecological effects of excessive nitrogen deposition on two broad-leaved forest species,i.e.,Manchurian ash(Fraxinus mandshurica Rupr.)and Mongolian oak(Quercus mongolica Fish.ex Ledeb).Results showed that 1)CO_(2) diffusional limitations(i.e.,stomatal limitation,lsc,mesophyll limitation,lm)of both species decreased by more than 10%after nitrogen addition,then increased with increasing nitrogen supply,while biochemical limitation(lb)increased by more than 10%after nitrogen addition,then decreased with increasing nitrogen supply.2)Both lsc and lm reached minimum values of 18.4%and 18.0%(Manchurian ash-August),21.6%and 19.7%(Mongolian oak-July),and 21.6%and 20.1%(Mongolian oak-August),while lb reached a maximum value of 63.6%(Manchurian ash-August)and 59.7%and 58.3%(Mongolian oak-July and August)under MN treatment,indicating that soil nitrogen addition of 46 kg·ha^(-1)·year^(-1) had the greatest photo-synthesis-promoting effect.3)The enhancement of plant photosynthetic capacity during soil nitrogen supply predominantly resulted from the weakening of CO_(2) diffusional limitations,in which stomatal conductance to CO_(2)(gsc,i.e.,lsc)was the primary limiting factor affecting plant photosynthesis.4)The three photosynthetic li-mitations(lsc,lm,and lb)did not show any significant differences between July and August,indicating that the primary photosynthetic role of lsc may lack seasonal variation.5)Soil nitrogen addition within a certain content range did not significantly affect the water use potential of plants.

关 键 词：气孔限制 叶肉限制 生化限制 氮添加 光合能力 

分 类 号：Q945.11[生物学—植物学]