土壤微生物群落变化Word文件下载.docx
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土壤微生物群落变化Word文件下载.docx
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Shine1999;
Wardleetal.1999;
DeDeynetal.2004).Secondly,changesinecosystemproductivitywhenPFGsarelostcaninducechangesinCandNallocationtosoilsandthereforeaffectthegrowthandactivityofbelow-groundcommunities(Wardleetal.1999;
实验设计:
根据物种C:
N以及生活型将群落中物种分为5个不同的功能群。
移除实验共16个处理(分别移除0、1、2、3和4种功能群),每个处理5个
重复。
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土壤微生物PLFA分类依据
1)PLFAsspecifictobacteria(i14:
0,a15:
0,i15:
0,i16:
0,
a17:
0,i17:
0,16:
137c,17:
138,18:
139,18:
1
andcy19:
0),fungi(18:
236,9)andactinobacteria(1
16:
0,10Me17:
0,and10Me18:
0)wereusedtodeterminetheabundanceofthesemicrobialgroupsandtocalculatethebiomass-basedratiooffungaltobacterialmicrobes(Frosteg?
rd,Tunlid&
B?
?
th2011).Wealsocalculatedtherelativeabundance(mol%)ofeachmicrobialgroup,whichwasusedtodescribethestructureofthemicrobialcommunity.
2)actinomycetes(10Me16:
0and10Me18:
0),
Mongoliangrassland.
(DimaChen,QingminPan,YongfeiBaietal.JournalofEcology2016,104,734743.)
植物功能群丧失对土壤微生物群落及净生态系统交换的影响(IMGRE项目)
37c,cy1
0Me
gram-positivebacteria(G+;
i14:
0,a17:
0andi17:
0);
gram-negativebacteria(G-;
16:
1w7c,16:
1w9c,cy17:
0®
7c,17:
138c,18:
1®
7c,cy19:
0w7candcy19:
0d9c);
fungi(F;
18:
1w9cand18:
236c)(FiererandJackson2006;
Willersetal.2015;
Chenetal.2016).
变异分配分析,分析不同因素对某种现象的解释
variationpartitioninganalyses(Lep?
etal.2011)wereusedtodeterminetherelativeimportanceofthenumberofPFGslost,PFGidentity,above-groundplantbiomass,soilpropertiesandnematodefoodresourcesonbelow-groundcommunitygroups.
1.PEG与地下生物群落的关系:
1)PEG缺失导致土壤微生物和线虫生物量和丰度下降,2)真菌与细菌
生物量比以及以真菌为食与以细菌为食的线虫丰度比下降。
1)Suchnegativeeffectscouldbeexplainedbyreductionsinthequalityandquantityofresourcesavailabletothebelow-groundcommunitiesresultingfromdecreasesinabove-groundplantbiomassanddecreases
intheprobabilityofincludingkeyPFGofPBorPRforthelow
PFG-richnessplots(Gastine,Scherer-Lorenzen&
Leadley2003;
Milcuetal.2008;
Viketoftetal.2009).
2)Thedominantroleofthebacterial-basedenergychannelinthelowPFGdiversitycommunitiesmightbeexplainedbythedecreasedquantityofplantmaterialstothebelow-groundorganisms(Wardleetal.2004).
2.由于PEG缺失造成地上生物量下降对地下生物群落的影响:
地下生物群落各组分生物量、丰度同地上生物量正相关。
Thisfindingisalsoconsistentwiththemassratiohypothesis,whichpredictsthattherelativeeffectofindividualPFGsorplantspeciesonecosystempropertiesshouldbeproportionaltotheirrelativecontributiontocommunityproductivity(Grime1998).Mostbelow-groundorganismsareheterotrophsthatrelyontheplant-derivedresiduesenteringthesoilvialeafandrootlitterandrhizodeposition(Spehnetal.2000;
Zaketal.2003;
Wardleetal.2004).
3.PEG缺失、地上生物量以及植物组成对地下生物群落的相对影响:
地下生物群落的变异主要来源于PEG的特性以及PEG的生物量。
BecausethecompositionofplantlitterandrootexudatesdiffersamongplantspeciesandPFGs,changesinplantdiversityandinPFGsarelikelytoalterthequalityofresourcessupportingthebelow-groundcommunities(Zaketal.2003;
Milcuetal.2006).2)ThehigherC:
NratiosofthedominantPFGsproducedlitterwithahigherC:
Nratio(Wuetal.2015),whichmayhaveenhancedthebiomassorabundanceofbelow-groundcommunitygroups(Bardgett&
DeDeynetal.2004).Inaddition,thedominantPFGsmayhaveprovidedphysicalprotectionforbelow-groundcommunitiesbyproducing
moreplantlitter(Eisenhaueretal.2010)
4.PEG缺失造成土壤碳固存下降:
碳固存能力下降与地上植物生物量和地下生物群落变化相关
1)TheamountofCstoredinanecosystemisdeterminedbythebalaneebetweenCassimilation
(viaphotosynthesis)andrespiration(ineludingbothheterotrophieandautotrophicrespiration)(DeDeyn,Cornelissen&
Bardgett2008).
2)DifferencesinPFGtraits(e.g.leafareaindex)influeneephotosyntheticrateand
communityproductivity,whichinturnmayaffectecosystemCsequestration(Wardetal.2009).
3)Relativetofungal-basedsoilfoodwebs,bacterialbasedsoilfoodwebshavehigheramountsofavailablenutrientsandloweramountsofnutrient-richorganicmatter(DeDeyn,Cornelissen&
Bardgett2008;
deVriesetal.2013).ThehighamountsofavailablenutrientscouldleadtohigherratesofdecompositionofsoilorganicmatterandthustoincreasedlossesofCtotheatmosphere.
2.EstimationbyPLFAofMicrobialcommunitystructureassociatedwiththerhizosphereofLygeumspartumandPiptatherummiliaceumgrowinginsemiaridminetailings(LucaCarrasco,AndreasGattiinger,AndreasFlie?
bach,AntonioRold印,MichaelSchloter,FuensantaCaravaca.2010,MicrobEcol,60:
265-271.)
在半干旱矿尾上两种禾本科植物根际微生物群落结构的PIFA估算
微生物对土壤的影响
Microbialpopulationsandtheiractivitiesarefundamentalformaintainingsoilquality,sincetheymediatetheprocessesoforganicmatterturnover,nutrientcycling,andstructureformationandstabilisation(Rold岔Aetal.,1994).
植物组分对微生物的影响
Plantscanaffectavailablesoilcarbon,temperature,andwatercontentandthushavethepotentialtoaffectmicrobialcommunitycompositionandfunction(PotthoffMetal.,2006).
微生物的生理状况反映
PhysiologicalstateofmicrobialcommunitieswasdeterminedusingtheratiosofMUFA/SATFAandtheratiosofcyclopropylPLFAstotheirmonoenoicprecursors(cy17:
0+cy19:
0/16:
1w7+18:
1w7).
多年生植物较一年生植物土壤微生物生物量高的原
因,以及出现相反情况的原因
1)TotalamountofPLFAintheperennialspeciesbecausethisspeciespresentsadenseandfibrousrootsystem(DeBaetsSetal.,2007)andpresumablysupplieshigherCtothesoilmicrobialbiomassthantheannualgrass.
2)Rhizodepositionqualityismoreimportantthanitsquantityforregulatingmicrobialbiomass.Thus,therootexudatesdepositedbytheannualspeciesweremoreeffectiveforpromotingmicrobialbiomass.Therootbiomassofperennialspeciesisricherincellulosethanthatofannualspecies(DeBaetsSetal.,2007),whichislesseasilydegradedbysoilmicroorganisms.
细菌、放线菌更能适应严峻、不利的环境状况
1)Gram-negativebacteriaareabletoutiliseagreatervarietyofCsourcesandadaptquickertoadverseconditionssuchasthoseofourpollutedsoil(HinojosaMBetal.,2005).
2)Actinobacteriamayformactinosporestheybetter
surviveinrelativelyharshsoilenvironments(desiccationandheat).
纤维素含量咼的根有利于真菌的定植与生长,真菌是光合产物的汇。
TherootsystemofL.spartumpresentsahighercellulosecontentthanthatofP.miliaceum,whichfavourscolonisationandgrowthoffungi-producingextracellularcellulases(HenriksenTMetal.,2002).
ThetotalpercentageofmycorrhizalcolonisationiscorrelatednegativelywiththeconcentrationofsolubleCfractions(MuthukumarTetal.,2000)indicatingthatmycorrhizalfungiactasstrongsinksforphotosynthates.
单不饱和脂肪酸与饱和脂肪酸比反映了微生物对饥饿胁迫的响应的适应机制。
Theincreaseintheratioofsaturatedtounsaturatedfattyacidsisacommonadaptationmechanismdevelopedbymicroorganismsinresponsetostarvationstress.Theratiohasbeenusedasavaluableindicatorofsubstrateavailabilityinsoil[32].MUFA/SATFAratios>
1havebeenobservedinsoilswithhighCcontentandorganicinputs,and<
1forsoilscharacterisedbylowsubstrateavailability.
cyc/prec也是一种饥饿引起的适应性机制(细胞膜流动性)。
Theincreaseincyclopropylfattyacids(cy17:
0andcy19:
0)isanotheradaptationmechanismthatisinducedbystarvationorheavymetaltoxicity(Frosteg?
rdetal.,1993;
GuckertJBetal.,1985)andtheresultantincreaseinmembranefluidity.Theconversionofmonoenoicprecursors(prec)intocyclopropylfattyacids(cyc)helpstomaintainafunctionallivingmembranebyminimisingthemembranelipidlossesorthechangesinmembranefluidity.Ithasbeenobservedthatthecyc/precratiois>
0.1underenvironmentalstress.
3.Shrub-encroachmentinducedalterationsininputchemistryandsoilmicrobialcommunityaffecttopsoilorganiccarboninanInnerMongoliangrassland(LuhongZhou.HeLi.HaihuaShen.YunpingXu.YinghuiWang.AijunXing.JingyunFang,Biogeochemistry,2017,)
灌木入侵造成输入物化学组成以及微生物群落的改变从而影响了内蒙古草原表层土壤有机碳
本文主要结论
1)SOCintheshrubpatcheswasderivedmainlyfromleaves,whereasSOCinthegrassymatrixwascomposedofamixtureoffreshroot-andleafderivedcompounds.
2)ComparedwithpuregrasslandtheSOCdecreasedby29%intheshrub-encroachedgrasslands(SEGs),andthisdecreasewasenhancedbyincreasingshrubcover.
3)Compared
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- 关 键 词:
- 土壤 微生物 群落 变化