【作者】 王倩；

【导师】 李少宁； 张维康；

【作者基本信息】 沈阳农业大学 ， 风景园林硕士（专业学位）， 2024， 硕士

【摘要】 植物通过叶片尖端放电和自身光合作用向空气中释放空气负离子（Negative air ion,简称NAI）可以达到净化空气的功效。本研究选择6种北京地区典型绿化树种,油松（Pinus tabuliformis）、白皮松（Pinus bungeana）、国槐（Styphnolobium japonicum）、栾树（Koelreuteria paniculata）、元宝枫（Acer truncatum）和栓皮栎（Quercus variabilis）,利用开顶箱（OTC）控制法开展控制实验,通过测定有植物实验组各树种释放的空气负离子浓度、生理指标（净光合速率P_n、胞间二氧化碳浓度C_i、蒸腾速率T_r、气孔导度G_s、固定荧光F_o、可变荧光F_v、光能转化效率F_v/F_m、叶绿素含量）和叶片形态指标（叶面积、比叶面积、叶尖数、叶片长宽比、叶片周长、叶片含水量）,计算五个能力指标:NAI释放贡献率L、NAI释放系数n、NAI释放速率s、NAI瞬时现存量v和NAI释放总量Z,探究不同树种NAI释放能力对生理形态指标的响应机制。研究结果表明:（1）植物释放NAI能力对生理指标产生不同响应。不同树种NAI释放能力受光合指标影响差异显著。整体来看,各光合指标对NAI释放贡献率L和释放系数n呈正向影响,NAI释放贡献率L变动范围为74.74%～84.64%,释放系数n变动范围为3.12～5.58,对阔叶树种的影响效果要强于针叶树种;对NAI释放速率s、瞬时现存量v和释放总量Z在阔叶树种中总体上呈正向效应,针叶树种中呈显著负向效应,变动范围分别为释放速率s:（0.79±0.14～3.73±0.28）万个·cm^-2·min^-1、瞬时现存量v:（7.9±1.4～37.3±2.8）万个·cm^-2、释放总量Z:（94.53±17.01～447.21±67.91）万个·cm^-2·h^-1。荧光参数对不同树种NAI释放能力影响差异显著,整体而言,对针叶树种影响程度大于阔叶树种,阔叶树种的释放贡献率L变幅为4.1%～5.8%,释放系数n变幅为60%～62.3%,针叶树种的释放贡献率L变幅为0.5%～1%,释放系数n变幅为40%～41.9%。叶绿素含量对植物NAI释放贡献率L和释放系数n具有促进作用;对植物NAI释放速率s、瞬时现存量v和释放总量Z分针、阔两种作用方式,针叶树种为抑制,阔叶树种为促进。（2）植物释放NAI能力受叶片形态影响差异显著。整体上叶尖数对树种释放NAI能力影响阔叶（上升幅度为100%±12%）明显大于针叶（上升幅度为50%±1.3%）,释放贡献率L和释放系数n受叶片面积、比叶面积影响在阔叶树种中L升幅6%、n升幅100%明显大于针叶树种L升幅1%、n升幅40%;叶片面积、比叶面积与阔叶树种NAI释放速率s、瞬时现存量v和释放总量Z无明显相关性,与针叶树种呈负相关。叶片长宽比整体上对植物NAI释放贡献率和释放系数有促进作用,随着叶片长宽比的增大,L、n呈上升趋势,L约上升10%,n约上升230%,在阔叶树种中叶片长宽比对NAI释放速率s、瞬时现存量v、释放总量Z没有显著影响,在针叶树种中呈负向影响。（3）6种典型绿化树种总体表现为针叶树种的NAI释放能力高于阔叶树种。针叶树种NAI释放能力显著高于阔叶树种。对于释放贡献率L和释放系数n油松（L:84.64%±1.59%、n:5.58±0.70）最高,白皮松次之,栓皮栎最低（L:74.74±6.10%、n:3.12±0.83）;对于释放速率s、瞬时现存量v和释放总量Z均表现为白皮松最高,栓皮栎最低。释放贡献率L（r=0.945,P<0.01）和释放系数n（r=0.921,P<0.01）与生理指标综合得分呈显著正相关关系;释放系数n与叶片形态指标呈显著正相关关系（r=0.893,P<0.05）。叶尖数、净光合速率P_n与NAI能力指标相关性最强,胞间CO₂浓度、蒸腾速率T_r、气孔导度G_s、叶片面积次之,其余指标与NAI能力指标相关性不强。综上所述,不同树种生理和叶片形态指标对其自身NAI释放能力存在一定相关性,通过综合评价得出针叶树种NAI释放能力显著高于阔叶树种,且叶尖数对植物释放NAI能力影响最大,比叶面积对植物释放NAI能力影响最小。上述结果可为未来选择较好的园林绿化树种建设良好的生态环境提供科学依据。更多还原

【Abstract】 Plants can purify the air by releasing negative air ions（NAI）into the air through leaf tip discharge and their own photosynthesis.This study selected six typical greening tree species in Beijing,including Pinus tabuliformis,Pinus bungeana,Styphnolobium japonicum,Koelreuteria paniculata,Acer truncatum,and Quercus variabilis,and conducted control experiments using the open top box（OTC）control method.The air negative ion concentration,physiological indicators（net photosynthetic rate P_n,intercellular carbon dioxide concentration C_i,transpiration rate T_r,stomatal conductance G_s）released by each tree species in the plant experimental group were measured.Fixed fluorescence F_o,variable fluorescence F_v,light energy conversion efficiency F_v/F_m,chlorophyll content,and leaf morphology indicators（leaf area,specific leaf area,number of leaf tips,leaf length to width ratio,leaf circumference,and leaf water content）were calculated.Five ability indicators were calculated:release contribution rate L of NAI,release coefficient n of NAI,release rate s of NAI,instantaneous standing quantity v of NAI,and total release amount Z of NAI.The response mechanism of NAI release ability of different tree species to physiological morphology indicators was explored.The research results indicate that:（1）The ability of plants to release NAI varies in response to physiological indicators.The NAI release ability of different tree species is significantly affected by photosynthetic indicators.Overall,various photosynthetic indicators have a positive impact on the contribution rate L and release coefficient n of NAI release.The variation range of NAI release contribution rate L is 74.74%-84.64%,and the variation range of release coefficient n is 3.12-5.58.The impact on broad-leaved tree species is stronger than that on coniferous tree species;The overall positive effects of NAI release rate s,instantaneous standing stock v,and total release Z were observed in broad-leaved tree species,while significant negative effects were observed in coniferous tree species,with variation ranges of release rate s:0.79±0.14～3.73±0.28 million pieces·cm^-2·min^-1,instantaneous standing stock v:7.9±1.4～37.3±2.8 million pieces·cm^-2,and total release Z:94.53±17.01～447.21±679100pieces·cm^-2·h^-1.The fluorescence parameters have a significant impact on the NAI release ability of different tree species.Overall,the impact on coniferous tree species is greater than that on broad-leaved tree species.The release contribution rate L of broad-leaved tree species varies from 4.1%to 5.8%,and the release coefficient n varies from 60%to 62.3%.The release contribution rate L of coniferous tree species varies from 0.5%to 1%,and the release coefficient n varies from 40%to 41.9%.The chlorophyll content has a promoting effect on the contribution rate L and release coefficient n of plant NAI release;The two modes of action on plant NAI release rate s,instantaneous standing stock v,and total release Z are needle and broadleaf,with coniferous tree species as inhibitors and broadleaf tree species as promoters.（2）The ability of plants to release NAI varies significantly depending on leaf morphology.Overall,the number of leaf tips has a significant impact on the ability of tree species to release NAI.Broadleaf（with a 100%±12%increase）is significantly greater than coniferous（with a 50%±1.3%increase）,and the release contribution rate L and release coefficient n are affected by leaf area and specific leaf area.In broadleaf species,the increase in L is 6%and the increase in n is 100%,which is significantly greater than that in coniferous species by 1%and 40%,respectively;There is no significant correlation between leaf area,specific leaf area,and NAI release rate s,instantaneous standing stock v,and total release Z of broad-leaved tree species,but a negative correlation with coniferous tree species.The overall aspect ratio of leaves has a promoting effect on the contribution rate and release coefficient of plant NAI.As the aspect ratio of leaves increases,L and n show an upward trend,with L increasing by about10%and n increasing by about 230%.In broad-leaved tree species,the aspect ratio of leaves has no significant effect on the NAI release rate s,instantaneous standing quantity v,and total release quantity Z,but has a negative impact in coniferous tree species.（3）The overall performance of the six typical greening tree species is that the NAI release capacity of coniferous tree species is higher than that of broad-leaved tree species.The NAI release ability of coniferous tree species is significantly higher than that of broad-leaved tree species.For the release contribution rate L and release coefficient n,Pinus tabulaeformis（L:84.64%±1.59%,n:5.58±0.70）is the highest,followed by Pinus bungeana,and Quercus variabilis（L:74.74%±6.10%,n:3.12±0.83）is the lowest;For the release rate s,instantaneous standing stock v,and total release Z,Pinus bungeana has the highest release rate,while Quercus variabilis has the lowest release rate.The release contribution rate L（r=0.945,P<0.01）and release coefficient n（r=0.921,P<0.01）are significantly positively correlated with the comprehensive score of physiological indicators;The release coefficient n is significantly positively correlated with leaf morphology indicators（r=0.893,P<0.05）.The correlation between leaf tip number,net photosynthetic rate P_n,and NAI ability indicators is strongest,followed by intercellular CO₂concentration,transpiration rate T_r,stomatal conductance G_s,and leaf area.The correlation between other indicators and NAI ability indicators is not strong.In summary,there is a certain correlation between the physiological and leaf morphology indicators of different tree species and their own NAI release ability.Through comprehensive evaluation,it is found that the NAI release ability of coniferous tree species is significantly higher than that of broad-leaved tree species,and the number of leaf tips has the greatest impact on the NAI release ability of plants,while the specific leaf area has the smallest impact on the NAI release ability of plants.The above results can provide scientific basis for selecting better landscaping tree species to build a good ecological environment in the future.更多还原