Study On The Characteristics Of Release BVOCs Of Eight Typical Landscape Tree Species In Beijing

In this paper,taking eight typical landscape tree species(coniferous species: Platycladus orientalis,Pinus tabuliformis,Sabina chinensis,Pinus bungeana;Broad-leaved tree species:Salix babylonica,Sophora japonica,Ginkgo biloba and Koelreuteria paniculata)as research objects,the composition,dynamic change characteristics of Volatile Organic Compounds(BVOCs)were determined by the dynamic headspace collection method of living plants with solid adsorbent and gas chromatography-mass spectrometry in Gaoliying Research Base,Shunyi,Forestry Fruit Tree Science Institute,Beijing.And the BVOCs release of different landscape tree species were further compared.This study is aiming to find the special components and dynamic variations of BVOCs with functions such as health care,bacteriostasis,and air purification,and provide theoretical basis for the species selection of landscape trees,plant arrangement scientifically and efficiently from the aspect of chemical ecology.Furthermore,the function of releasing BVOCs of the existing landscape tree species in Beijing was evaluated scientifically.The main conclusions of this study are as follows:(1)The contents of BVOCs released by coniferous trees varied significantly among species.Olefins are the dominant contents,ranging from 56.22% ~ 68.38% of the total released amount.The components included:-pinene,cyrene,limonene,3-carannene,dextroterpendiene,laurene,alpha-cypress.Alkanes and aromatic hydrocarbons are the next,with the proportion accounting for 17.66%~26.32%.Esters,aldehydes,ketones,alcohols and organic acid compounds accounted for a total of 13.96%~16.14%.Despite of their small proportions,they include acetate pine oil ester,linalool propionate,octyl aldehyde,decyl aldehyde,geranium aldehyde,lauraldehyde,cedar alcohol,terpene alcohol and other organic compounds which are important sources of the fresh smell of pine for conifer species.(2)The contents of BVOCs released by broad-leaved tree species were evenly distributed among species,with 30.65~16.74% of aromatic hydrocarbons,24.31~16.62% of alkane compounds,20.75-15.48% of olefins,17.39~16.69% of alcohols and 14.18%~9.95%of aldehydes.There are only a few alkenes released by olefins species,including isoprene,-pinene,laurene and 3-carannene.The releases of hardwood species are rich in alcohols,including 2-ethylhexanol,l-menthol,lauryl alcohol,19-alkanol,2-heptanol,linalool,l-menthol,plant alcohol.Similarly,broad-leaved trees also releases a variety of aldehydes.Besides common octanal,geranium aldehydes,decyl aldehydes high content of hexanaldehyde,lauraldehyde,L-(-)-glyceraldehyde and salicylaldehyde were also detected.In addition to the above mentioned BVOCs,isobornyl acetate is also a of the sources of plant fragrance released by hardwood.(3)The BVOCs released by different landscape tree species have different dynamic change characteristics.For olefin,the seasonal change rules of Platycladus orientalis and Pinus tabuliformis were consistent,showing spring > summer > autumn.The total olefin amounts across three seasons of Platycladus orientalis(65.28%±6.38%)were 4 times of those for Koelreuteria Paniculata(15.58%±8.42%)Pinus tabuliformis,Sabina chinensis and Salix babylonica showed summer > spring > autumn,Pinus bungeana,Sophora japonica and Ginkgo biloba showed spring > summer > autumn.Therefore,landscape trees are more likely to release olefin compounds in spring and summer.For the aldehyde,Pinus tabuliformis and Ginkgo biloba showed autumn > spring > summer.Sabina chinensis and Koelreuteria paniculata showed summer > autumn > spring.Salix babylonica and Sophora japonica showed autumn > summer > spring;Platycladus orientalis showed spring(12.14%)>summer(6.65%)> autumn(2.08%),Pinus bungeana is summer(16.27%)> spring(10.76%)>autumn(4.15%).Therefore,most landscape tree species are more likely to release aldehydes in summer and autumn.The coniferous species release a large amount of terpenes such as olefin and pinene BVOCs as well as a large amount of ?-pinene and ?-pinene,which make coniferous species have their unique pines and cypress fragrance,which makes people relaxed and refreshed.(4)The BVOCs released by different landscape tree species have different daily change characteristics.The content of olefin compounds released by conifer species was higher at night than in the morning.The concentrations of olefins decreased with the increase of temperature.The hardwood species mainly released isoprene,and the activity of isoprene synthase increased with the increase of temperature,and the release amount of isoprene increased.When a certain temperature was reached,the activity of isoprene synthase began to decrease,and the release amount of isoprene also decreased.