Yang W.,Nanjing University |
Yan Y.,Nanjing University |
Jiang F.,Nanjing University |
Leng X.,Nanjing University |
And 3 more authors.
Plant and Soil | Year: 2016
Aims: Plant invasion has been reported to alter ecosystem carbon (C) and nitrogen (N) cycling processes and pools. The mechanisms involved in how plant invasion affects the soil microbial community—the primary mediator of soil C and N cycling—remain poorly understood. The objective of this study was therefore to evaluate the effect of plant invasion on the soil microbial community in a coastal wetland of eastern China. Methods: We investigated the impact of an exotic C4 perennial grass, Spartina alterniflora, on the soil microbial community structure based on phospholipid fatty acids (PLFAs) analysis and chloroform fumigation-extraction by comparing it to that of bare flat and native C3 plants Suaeda salsa and Phragmites australis communities. Results: Spartina alterniflora invasion significantly increased soil microbial biomass C and the total and various types of PLFAs compared with bare flat, Suaeda salsa and Phragmites australis communities. Increased concentrations of soil moisture, electrical conductivity, water-soluble organic carbon (WSOC), and total, labile and recalcitrant soil organic C and N, and decreased soil pH in Spartina alterniflora community explained 65.9 % of the total variability in the PLFAs. WSOC and soil labile organic N were strongly correlated with PLFAs, whereas soil pH was negatively related to PLFAs. Conclusions: A 10-year Spartina alterniflora invasion significantly altered soil microbial biomass and community structure by increasing available substrate. The changes in soil microbial biomass and community structure may in turn enhance soil C and N sequestration in a coastal wetland of eastern China. © 2016, Springer International Publishing Switzerland.
Yang W.,Nanjing University |
Yang W.,Jiangsu Engineering Laboratory of Wetland Restoration |
An S.,Nanjing University |
An S.,Jiangsu Engineering Laboratory of Wetland Restoration |
And 7 more authors.
Ecological Engineering | Year: 2016
Plant invasion may impact ecosystem structure and function, and further affect soil organic matter (SOM) dynamics. However, the influence of plant invasion on soil organic carbon (C) and nitrogen (N) pools sizes, stability, and turnover in SOM of invaded ecosystems is not fully understood. In this study, soil C and N contents, and δ13C and δ15N values of free light fraction (LF), intra-aggregate particulate organic matter (iPOM) and mineral-associated organic matter (mSOM) were investigated in an invasive Spartina alterniflora community, adjacent bare flat and native Suaeda salsa and Phragmites australis communities. Short-term S. alterniflora invasion significantly enhanced organic C and N contents in SOM, free LF, iPOM, mSOM compared with bare flat and increased the proportion of allocated C in iPOM compared with S. salsa and P. australis soils (0-0.30m depth). The proportion of the S. alterniflora-derived C in free LF and iPOM were significantly higher than that in mSOM, and the highest S. alterniflora-derived C content was found in iPOM of S. alterniflora soil. The most enriched δ15N values were found in S. alterniflora soil. Increased δ15N values and decreased C:N ratios from the free LF to iPOM to mSOM in S. alterniflora soil indicated a greater degree of decomposition. The results suggest that 10-year S. alterniflora invasion significantly alters soil organic C and N pools sizes and stability through changing plant residuals input, physical distribution of S. alterniflora-derived C and C turnover in SOM fractions. © 2015 Elsevier B.V..