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2491888 
Journal Article 
Response of organic carbon mineralization and microbial community to leaf litter and nutrient additions in subtropical forest soils 
Wang, Q; Wang, S; He, T; Liu, Li; Wu, J 
2014 
1 
Soil Biology and Biochemistry
ISSN: 0038-0717
EISSN: 1879-3428 
71 
13-20 
WOS:000333508400002 
Microorganisms are vital in soil organic carbon (SOC) mineralization. The deposition of atmospheric nitrogen (N) and phosphorus (P), as well as leaf-litter addition, may affect SOC mineralization and microbial community structure by changing the availability of soil nutrients and carbon (C). In this study, we added leaf-litters labeled by C-13 (Pinus massoniana and Michelia macclurei) and nutrients (ammonium chloride and monopotassium phosphate) alone and in combination to soils collected from a coniferous forest in subtropical China. We aimed to investigate the effect of leaf-litter and nutrient addition on SOC mineralization and soil microbial community. CO2 production was continuously measured during 120-day laboratory incubation, and CO2 sources were partitioned using C-13 isotopic techniques. The addition of P. massoniana and M. macclurei leaf-litters increased SOC mineralization by 7.4% and 22.4%, respectively. N and P addition alone decreased soil respiration by 6.6% and 71%, respectively. Compared with P addition, N addition exerted a higher inhibitory effect on SOC mineralization induced by leaf-litter addition. Leaf-litter addition stimulated soil microbial activity and decreased the ratio of bacteria to fungi as a result of greater promotion on fungal growth. Moreover, 16:0 and 18:1 omega 9c phospholipid fatty acids (PLFAs) had greater amount of C-13 incorporation than other PLFAs, especially in nutrient-addition treatments. These results suggested that increased C input through leaf litter can stimulate SOC mineralization, whereas atmospheric N and P deposition can reduce this stimulatory effect and promote soil C storage in subtropical forests. Our results also illustrated that the use of C-13-labeled leaf litter coupled with C-13-PLFA profiling is a powerful tool for determining the microbial utilization of C. (C) 2014 Elsevier Ltd. All rights reserved. 
Soil organic C mineralization; Litter addition; Nutrient availability; Nitrogen deposition; Subtropical forest; Priming effect; Phospholipid fatty acids