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《施肥對(duì)水曲柳和落葉松細(xì)根動(dòng)態(tài)影響的的研究》由會(huì)員上傳分享,免費(fèi)在線閱讀,更多相關(guān)內(nèi)容在學(xué)術(shù)論文-天天文庫。
1、東北林業(yè)大學(xué)博士學(xué)位論文也分別占到60%左右。研究分析表明,兩樹種各徑級(jí)細(xì)根生長可能要受到樹種自身因素和環(huán)境因素的相互控制,而不同徑級(jí)細(xì)根死亡則可能主要受外環(huán)境因素的作用。5.細(xì)根周轉(zhuǎn)估計(jì)表明:施肥使兩樹種不同土層、不同徑級(jí)細(xì)根周轉(zhuǎn)加快;兩樹種對(duì)照區(qū)和施肥區(qū)細(xì)根周轉(zhuǎn)隨土層增加而變小,隨直徑增大而減小,且施肥區(qū)大于對(duì)照區(qū);兩樹種間細(xì)根周轉(zhuǎn)也存在差異,落葉松要大于水曲柳。綜合分析表明,(1)施肥對(duì)水曲柳和落葉松人工林細(xì)根分布、生長和死亡影響不明顯,但施肥加快了兩樹種細(xì)根周轉(zhuǎn):(2)水曲柳和落葉松兩樹種具有不同的生物學(xué)特性。兩樹種細(xì)根的
2、生長可能受樹種內(nèi)在因素和外環(huán)境因素的相互作用控制。關(guān)鍵詞水曲柳;落葉松;施肥;細(xì)根;生長;周轉(zhuǎn);微根管AbstractFinerootisamajororganoftreesinabsorbingwaterandnutrition.Theproductionandturnoveroffinerootinforestecosystemsplayanimportantroleinterrestrialcarbonandnutritioncycles.ByusingMinirhizotron,thedistribution,produc
3、tion,mortalityandturnoveroffinerootamongdifferentsoildepthanddifferentdiameterwereinvestigatedneartwoyearsin18yearsoldpureManchurianash(Fraxinusmandshurica)andDavurianlarch犯arixgmelinii)plantations,whichwerefertilizedandlocatedonthesamestandconditions.Atthesametime,so
4、iltemperature,soilmoistureandnitrogenavailabilitywerealsomeasuredintheseplantations.Theresultswereshowedasfollows:1.Theresultsofstudyingonthedistributionoffinerootsuggested:(1)Asfortwotreesspeciesinfertilizedandcontrolledplots,thenumberoffinerootandrootlengthdensitywe
5、realldecreasedwithsoildepthincreased,thenumberoffinerootofManchurianashwasmorethanthatofDavurianlarch,finerootlengthdensityofManchurianashwasalsohigherthanthatofDavurianlarch.Bothoffinerootnumberandrootlengthdensityinfertilizedplotswerelessthanthoseincontrolledplots.M
6、ostofManchurianashfinerootoccurredinspringandsummer,butDavurianlarchfinerootmainlyoccurredinsummer.Forbothoftreesspeices,thefinerootlengthdensitywasnotsignificantlyaffectedbyfertilization,andwasalsonodifferenceamongdiverseseasons;(2)Fertilizationdidn’tsignificantlyaff
7、ectfinerootdiameterforManchurianashandDavurianlarchfineroot.Consideringtwotreesspeciesinfertilizedandcontrolledplots,themeanrootdiameterofManchurianashwasthinnerthanthatofDavurianlarch.AlthoughthediameterofManchurianashfinerootwassigllificantlychangedwithdifferentseas
8、ons,andbecamethickerindeepsoilthaninshallowsoil,thisstatusdidn’texhibitforDavurianlarchfineroot.2.Theexperimentoffinerootdyn