TY - JOUR
T1 - Phosphorus addition alters the response of soil organic carbon decomposition to nitrogen deposition in a subtropical forest
AU - Fang, Xiang Min
AU - Zhang, Xiu Lan
AU - Chen, Fu Sheng
AU - Zong, Ying Ying
AU - Bu, Wen Sheng
AU - Wan, Song Ze
AU - Luo, Yiqi
AU - Wang, Huimin
N1 - Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2019/6
Y1 - 2019/6
N2 - The continuous increase of nitrogen (N) deposition may exacerbate phosphorus (P) deficiency, which affects soil organic carbon (SOC) decomposition by changing microbial community characteristics in subtropical forests with highly weathered soils. However, there is currently little information about the role of P and the N × P interaction in SOC dynamics. Here, a field nutrient manipulation experiment was established in a subtropical plantation forest in China. Soils collected from simulated N deposition and P addition treatments for 5 years were incubated at 25 °C for 130 days. Soil microbial composition was measured using the phospholipid fatty acid method and the enzyme activities related to SOC hydrolysis were measured. The SOC concentration and δ 13 C in bulk soil and three particle-size fracfractions were also determined. The cumulative CO 2 respired over 9 days, representing the utilization of carbon sources under field conditions, increased with N deposition levels under the without-P treatment, while no significant differences were found among the three N deposition levels in the with-P treatment. Meanwhile, P addition generally suppressed the SOC decomposition during 130 days incubation. Similarly, P addition decreased the potential organic carbon decomposition (C 0 ) and C 0 /SOC ratio. In contrast, C 0 increased with N deposition in the without-P treatment, while was unaffected by N deposition under the with-P treatment, suggesting the response of SOC decomposition to N deposition was affected following P addition by alteration of SOC quality. Moreover, N deposition tended to deplete the δ 13 C of the SOC and P addition enriched the δ 13 C of the macro-particulate organic carbon. Addition of P increased total microbial, fungal and bacterial biomass values by 41.6%, 90.0% and 46.9%, respectively, whereas N deposition had no significant effect. Soil fungi/bacteria ratio significantly increased by N deposition and P addition, which partly explained the reduction of SOC decomposition after P addition. The cellobioside activity significantly decreased by 48.3% after P addition, while cellobioside and β-xylosidase activities increased with N deposition, suggesting that N deposition and P addition had opposite roles in the SOC stability. These results indicate that the positive effect of N deposition on SOC decomposition was suppressed when P was added by changing microbial community and enzyme activity and enhanced P availability may result in increased SOC accumulation under N deposition scenarios in subtropical forests.
AB - The continuous increase of nitrogen (N) deposition may exacerbate phosphorus (P) deficiency, which affects soil organic carbon (SOC) decomposition by changing microbial community characteristics in subtropical forests with highly weathered soils. However, there is currently little information about the role of P and the N × P interaction in SOC dynamics. Here, a field nutrient manipulation experiment was established in a subtropical plantation forest in China. Soils collected from simulated N deposition and P addition treatments for 5 years were incubated at 25 °C for 130 days. Soil microbial composition was measured using the phospholipid fatty acid method and the enzyme activities related to SOC hydrolysis were measured. The SOC concentration and δ 13 C in bulk soil and three particle-size fracfractions were also determined. The cumulative CO 2 respired over 9 days, representing the utilization of carbon sources under field conditions, increased with N deposition levels under the without-P treatment, while no significant differences were found among the three N deposition levels in the with-P treatment. Meanwhile, P addition generally suppressed the SOC decomposition during 130 days incubation. Similarly, P addition decreased the potential organic carbon decomposition (C 0 ) and C 0 /SOC ratio. In contrast, C 0 increased with N deposition in the without-P treatment, while was unaffected by N deposition under the with-P treatment, suggesting the response of SOC decomposition to N deposition was affected following P addition by alteration of SOC quality. Moreover, N deposition tended to deplete the δ 13 C of the SOC and P addition enriched the δ 13 C of the macro-particulate organic carbon. Addition of P increased total microbial, fungal and bacterial biomass values by 41.6%, 90.0% and 46.9%, respectively, whereas N deposition had no significant effect. Soil fungi/bacteria ratio significantly increased by N deposition and P addition, which partly explained the reduction of SOC decomposition after P addition. The cellobioside activity significantly decreased by 48.3% after P addition, while cellobioside and β-xylosidase activities increased with N deposition, suggesting that N deposition and P addition had opposite roles in the SOC stability. These results indicate that the positive effect of N deposition on SOC decomposition was suppressed when P was added by changing microbial community and enzyme activity and enhanced P availability may result in increased SOC accumulation under N deposition scenarios in subtropical forests.
KW - C natural abundance
KW - Nitrogen deposition
KW - Phosphorus addition
KW - Soil microbial community
KW - Soil organic carbon decomposition
KW - Subtropical forest
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U2 - 10.1016/j.soilbio.2019.03.005
DO - 10.1016/j.soilbio.2019.03.005
M3 - Article
AN - SCOPUS:85063114470
SN - 0038-0717
VL - 133
SP - 119
EP - 128
JO - Soil Biology and Biochemistry
JF - Soil Biology and Biochemistry
ER -