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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
