Comparative Of Chemical Properties And Enzyme Activities In Rhizosphere And Non-rhizosphere Soil Of Different Tsuga Longibracteata Forests In Tianbaoyan National Nature Reserve

Tsuga longibracteata Cheng is a unique tree species in China,which is rare and endangered now.It plays an important role in promoting forest succession,maintaining the balance and stability of ecosystem and water conservation.Howerver,its poor natrual regeneration is the critical problem for recovery and reconstruction of T.longibracteata forests.As active interface cycle of mass and energy fluxes,rhizosphere micro-environment most directly affects metabolism on plant roots and chemical property.Taking rhizosphere and non-rhizosphere soil of T.longibracteata and main associated tree species in 6 different forests as research object,such as T.longibracteata+Phyllostachys pubescens forest T.longibracteata+Schima superba forest,T.longibracteata+Rhododendron simiarum forest,T.longibracteata+Cunninghamia lanceolata forest,T.longibracteata+Cyclobalanopsis glauca forest and T.longibracteata pure forest,their chemical properties and enzyme activities were compared and researched.Then canonical correlation analysis was used to explore the relationship between chemical properties and enzyme activities.The results were as follows:(1)Chemical properties in rhizosphere and non-rhizosphere soil of different T.longibracteata forests were different.pH Values were lower in rhizosphere than in non-osphere soil in the 6 forests.Oganic matter,total nitrogen,hydrolyte-nitrogen,total phosphorus,available phosphorus,total potassium and available potassium content in rhizosphere soil were higher than in non-rhizosphere soil of the same forest type respectively.Chemical properties coefficient of variation less than 10%in rhizosphere and non-rhizosphere soil,which belonged to low variability.In the same forest,Oganic matte,total nitrogen and total phosphorus content in rhizosphere and non-rhizosphere soil reached significant level(p<0.05)(2)Enzyme activities in rhizosphere and non-rhizosphere soil of different T.longibracteata forests were also different.Variation range protease activity in rhizosphere and non-rhizosphere soil were 85.523-87.230 ?g/g and 85.523-87.230?g/g respectively.And invertase activity were 15.706-6.927 mg/g and 12.479-13.313 mg/g respectively.Cellulolytic enzyme activity in rhizosphere soil was 1.123-1.335 mg/g,and in non-rhizosphere soil was 0.744-1.123 mg/g.Urease activity in rhizosphere and non-rhizosphere soil were 0.677-0.794 mg/g and 0.564-0.645 mg/g respectively.Acid phosphatase activity in rhizosphere soil ranged from 0.504 mg/g to 0.637 mg/g,while in non-rhizosphere soil ranged from 0.288 mg/g to 0.324 mg/g.Enzyme activities in rhizosphere soil were all higher than in non-rhizosphere soil of the same forest type.Both of them reached significant level respectively(p<0.05),which showed that rhizosphere effects were obvious.(3)Canonical correlation analysis was done among chemical properties and enzyme activities in rhizosphere and non-rhizosphere soil of T.longibracteata.We found that there were certain correlations among chemical properties and enzyme activities in rhizosphere soil.Correlation degree between total potassium and available potassium of chemical properties was the greatest(0.9974).And correlation degree protease and acid phosphatase activity of enzyme activities was the greatest(0.8381).And the greatest negative correlation degree among chemical properties and enzyme activities were organic matter and cellulose enzyme(-0.6058).Other index among chemical properties and enzyme activities associated less.While in non-rhizosphere soil,total potassium and available potassium of chemical properties was also associated the most(0.9954).The greatest negative correlation degree among enzyme activities were invertase and cellulose enzyme(-0.7246).The association were also different among different chemical properties and enzyme activities.(4)pH Values of main associated tree species of T.longibracteata.were lower in rhizosphere soil than in non-rhizosphere soil respectively.Oganic matter,total nitrogen,hydrolyte-nitrogen,total phosphorus,available phosphorus,total potassium and available potassium content in rhizosphere soil were higher than in non-rhizosphere soil of the same species respectively.And protease,invertase,cellulase enzyme,urease and acid phosphatase in rhizosphere soil were also higher than that in non-rhizosphere soil.The 5 enzyme in different tree species were all characterized by positive enrichment.While the highest enrichment ratio was acid phosphatase in the 5 tree species.