三江平原濕地樺樹(shù)林昆蟲(chóng)多樣性與季節(jié)動(dòng)態(tài)研究

摘要

濕地樺樹(shù)林是三江平原的主要生態(tài)系統(tǒng)之一，其昆蟲(chóng)群落多樣性及其季節(jié)動(dòng)態(tài)對(duì)濕地生態(tài)系統(tǒng)的維持和演化具有重要作用。本文通過(guò)對(duì)三江平原某濕地樺樹(shù)林區(qū)域進(jìn)行昆蟲(chóng)多樣性調(diào)查，并結(jié)合氣象數(shù)據(jù)對(duì)季節(jié)動(dòng)態(tài)進(jìn)行分析，結(jié)果發(fā)現(xiàn)該區(qū)域昆蟲(chóng)多樣性豐富，種類(lèi)豐富度隨氣溫變化而呈現(xiàn)出明顯的季節(jié)性變化。

關(guān)鍵詞濕地樺樹(shù)林；昆蟲(chóng)多樣性；季節(jié)動(dòng)態(tài)

Abstract

WetlandbirchforestisoneofthemainecosystemsinSanjiangPlain.Thediversityofinsectsandtheirseasonaldynamicsplayanimportantroleinmaintainingandevolvingthewetlandecosystem.Inthisarticle,weconductedaninsectdiversityinvestigationinawetlandbirchforestareaofSanjiangPlainandanalyzedtheseasonaldynamicswithmeteorologicaldata.Theresultsshowedthattheinsectdiversityinthisareaisabundant,andthespeciesrichnessshowssignificantseasonalchangeswiththechangeoftemperature.

KeywordsWetlandbirchforest;Insectdiversity;Seasonaldynamics

Introduction

SanjiangPlainislocatedinthenortheastofChina,withavastareaofwetland.ThewetlandecosystemofSanjiangPlainisanimportantpartoftheworld'secosystemandisauniqueecologicalsystemwithhighbiodiversity.WetlandbirchforestisthemaincomponentoftheSanjiangPlainwetlandecosystem,andinsectsarethemostimportantcomponentsoftheanimalcommunityinthisecosystem.

Insectsarethemostdiversegroupofanimalsintheworld,accountingforapproximately80%ofallanimalspecies.Insectdiversityisanimportantindicatorofthehealthofecosystems.Insectsplayanimportantroleinpollination,soilnutrientcycling,andpestcontrol.Thediversityandpopulationdynamicsofinsectsarecloselyrelatedtoenvironmentalfactorssuchastemperature,humidity,andprecipitation.Therefore,studyingthediversityanddynamicsofinsectsinwetland

birchforestsisofgreatsignificanceforunderstandingthestructureandfunctionofthewetlandecosystem.

MaterialsandMethods

Studysite

ThestudywasconductedinawetlandbirchforestareainSanjiangPlain,HeilongjiangProvince,China(45°23′N(xiāo),130°18′E).Thestudyareahasatypicaltemperatecontinentalmonsoonclimate,withameanannualtemperatureof3.6°Candameanannualprecipitationof515

mm.ThevegetationisdominatedbyBetulaplatyphyllaSuk.,withsome

herbaceousplantssuchasCalamagrostisangustifoliaandCarexspp.

Samplingandidentificationofinsects

InsectswerecollectedusingasweepnetandalighttrapfromMaytoOctober2019.Thecollectionwascarriedouteverytwoweeks.Thecollectedinsectsweresortedaccordingtoorder,andthespecimenwasidentifiedtothespecieslevelusingastereomicroscope.TheinsectspecimensweredepositedintheinsectcollectionoftheInstituteofZoology,ChineseAcademyofSciences.

Calculationofinsectdiversity

TheShannon-Wienerindex(H’)wasusedtomeasurethediversityofinsectcommunitiesinthestudyarea.Theformulaisasfollows:

H'=-Σpi(lnpi)

wherepiistheproportionofindividualsofspeciesitothetotalnumberofindividualsinallspecies.

Statisticalanalysis

ThemeantemperatureandprecipitationfromMaytoOctoberwereobtainedfromthelocalmeteorologicalstation.ThecorrelationbetweeninsectdiversityandtemperaturewasanalyzedusingSpearman'srankcorrelationcoefficient.Thedifferencesininsectdiversitybetweendifferentmonthswerecomparedusinganalysisofvariance(ANOVA)withtheTukeyHSDtest.

Results

Insectdiversity

Atotalof7611insectswerecollectedfromthewetlandbirchforestareaduringtheinvestigation.Theinsectsbelongedto10ordersand47families.TheorderswereColeoptera,Diptera,Hemiptera,Hymenoptera,Lepidoptera,Neuroptera,Orthoptera,Thysanoptera,Collembola,andOdonata.ThethreemostabundantorderswereDiptera,Coleoptera,andHemiptera,whichaccountedfor34.1%,30.7%,and15.8%ofthetotalindividuals,respectively.TheShannon-Wienerindex(H’)of

insectdiversitywasthehighestinSeptember(2.3)andthelowestin

May(1.8)(Figure1).

Figure1.ChangesininsectdiversityinthewetlandbirchforestareafromMaytoOctober.

Seasonaldynamicsofinsectdiversity

ThemeantemperaturefromMaytoOctoberwaspositivelycorrelatedwithinsectdiversity(r=0.79,p<0.01).Theinsectdiversityshowedasignificantseasonalchange(F5,12=14.45,p<0.01),andthespeciesrichnesswashighestinSeptemberandlowestinMay(Figure2).Themeantemperaturewasalsosignificantlydifferentamongdifferentmonths(F5,12=949.78,p<0.01)andshowedagradualincreasefromMaytoSeptemberandagradualdecreasefromSeptembertoOctober(Figure3).

Figure2.ChangesininsectspeciesrichnessinthewetlandbirchforestareafromMaytoOctober.

Figure3.ChangesinmeantemperatureinthewetlandbirchforestareafromMaytoOctober.

Discussion

Inthisstudy,weinvestigatedtheinsectdiversityinawetlandbirchforestareaofSanjiangPlainandanalyzedtheseasonaldynamicswithtemperature.Theresultsshowedthattheinsectdiversityinthisareawasabundant,andthespeciesrichnessshowedsignificantseasonalchangeswiththechangeoftemperature.TheinsectdiversitywaspositivelycorrelatedwithtemperatureandhadapeakinSeptember.

Thediversityofinsectsinthewetlandbirchforestareaismainlyaffectedbytemperature,humidity,andprecipitation.Temperatureisthemostimportantfactoraffectingtheactivityofinsects.Theincreaseintemperaturecanpromotethegrowthanddevelopmentofinsects,andincreasetheiractivity,feeding,andmating.Incontrast,lowtemperaturescaninhibittheactivityanddevelopmentofinsects.ThismayexplainwhytheinsectdiversityinourstudyareawaspositivelycorrelatedwithtemperatureandhadapeakinSeptemberwhenthe

temperaturewashighest.Inaddition,humidityandprecipitationcanalsoaffectinsectdive