| The paper use three subtropical forest soils(natural evergreen broadleaved forest.Cunninghamia lanceolata plantation and Castanea henryi plantation),through laboratory incubation experiment,to explore the different incubation temperature(20 and 30?)under the add labeled Cunninghamia lanceolata leaves(LC),unlabeled(C)and the control(CT)influence the soil mineralization of soil organic carbon?properties of physical and chemical and microbial community structure.At the same time according to tracer of 13C to calculate of soil organic carbon priming effect(PE).It is very important to improve forest soil carbon cycling model.The main results are as follows:(1)The cumulative mineralization of 30? is 76.18%-183.96%higher than that of 20?,The temperature significantly increased promoted soil organic carbon mineralization.Adding labeled and unlabeled Cunninghamia lanceolata leaves not significant among 30?,but 20? addition of unlabeled is 6.86%-16.62%higher than addition of labeled,which will lead to calculate priming effect at 20? on the small side.The Q10 value is 2.18-3.38,adding labeled and unlabeled Cunninghamia lanceolata leaves lead natural evergreen broadleaved forest is 24.59%and 27.54%lower than the control,no significant difference between Cunninghamia lanceolata plantation;Castanea henryi plantation labeled and unlabeled is 55.04%and 50%higher than the control.(2)Add labeled and unlabeled Cunninghamia lanceolata leaves the cumulative mineralization is 15.72%-122.33%higher than the control means that add treatment significantly promote the soil organic carbon mineralization.The same treatment natural evergreen broadleaved forest is 34.10%-65.55%higher than Cunninghamia lanceolata plantation and 84.63%-250.26%higher than Castanea henryi plantation.The soil types had significant effects on the soil organic carbon mineralization.The correlation analysis showed that soil organic carbon content,C/N,DOC and MBC contents,pH showed significant positive correlation with the accumulation of mineralization.(3)The accumulation of PE(mg C·kg-1 dry soil)natural evergreen broadleaved forest at 20? is 34.84,30? is-33.03;Cunninghamia lanceolata Plantation at 20? is-51.61,30? is 8.38;Castanea henryi plantation 20? is 3.99,30? is 59.22.Temperature change of natural forest and Castanea henryi plantation the positive and negative priming effect,enhanced to positive priming effect of the Castanea henryi plantation.The labeled Cunninghamia lanceolata litter leaves produced the accumulation of CO2-C(mg C·kg-1 dry soil),natural evergreen broadleaved forest 20? and 30? is 138.93 and 220;Cunninghamia lanceolata plantation is 128.63 and 198.95;Castanea henryi plantation is 128.81 and 199.87,temperature rise promoted the litter decomposition.(4)Through correlation analysis,it can be concluded that soil organic carbon content,C/N and soil organic carbon accumulation is significantly negatively correlated with the accumulation of PE.The MBC content and pH value was significantly positively correlated with the accumulation of PE at 20?.The DOC,MBC content and pH value was significantly negatively correlated with the accumulation of PE at 30?.(6)Add Cunninghamia lanceolata leaves the natural evergreen broadleaved forest and Castanea henryi plantation fungi/bacteria ratio was significantly increased by 4.25%-79.89%,but had no significant effect on Cunninghamia lanceolata plantation;With the increase of incubation temperature the natural evergreen broadleaved forest and Castanea henryi plantation fungi/bacteria ratio was significantly decrease by 11.11%-33.33%,but had no significant effect on Cunninghamia lanceolata plantation.The 16:1 ? 9c in G-bacteria had a significant effect on the soil organic carbon priming effect,and the more 16:1 ?2 9c,the more obvious the soil organic carbon positive priming effect.G+/G-ratio compared with the control was low,the soil organic carbon priming effect was positive,while the G+/G-ratio was higher than the control,the soil organic carbon priming effect was negatively. |
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