Short-term C4 plant Spartina alterniflora invasions change the soil carbon in C3 plant-dominated tidal wetlands on a growing estuarine Island

• Published in: Soil biology & biochemistry 2006-12, Vol.38 (12), p.3380-3386
• Main Authors: Cheng, X, Luo, Y, Chen, J, Lin, G, Li, B
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biochemistry and biology; Biological and medical sciences; C3 plants; C4 plants; carbon; chemical constituents of plants; Chemical, physicochemical, biochemical and biological properties; Fundamental and applied biological sciences. Psychology; indigenous species; introduced plants; invasive species; nitrogen content; Organic matter; Physics, chemistry, biochemistry and biology of agricultural and forest soils; plant litter; roots; Scirpus mariqueter; soil chemical properties; soil depth; Soil science; Spartina alterniflora; stable isotopes
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2006.05.016

Spartina alterniflora is an invasive C4 perennial grass, native to North America, and has spread rapidly along the east coast of China since its introduction in 1979. Since its intentional introduction to the Jiuduansha Island in the Yangtze River estuary, Spartina alterniflora community has become one of the dominant vegetation types. We investigated the soil carbon in the Spartina alterniflora community and compared it with that of the native C3 Scirpus mariqueter community by measuring total soil carbon (TC), soil organic carbon (SOC), total soil nitrogen (TN), and the stable carbon isotope composition (δ13C) of various fractions. TC and SOC were significantly higher in Spartina alterniflora in the top 60 cm of soil. However, there was no significant difference in soil inorganic carbon (IC) between the two communities. Stable carbon isotopic analysis suggests that the fraction of SOC pool contributed by Spartina alterniflora varied from 0.90% to 10.64% at a soil depth of 0-100 cm with a greater percentage between 20 and 40 cm deep soils. The δ13C decreased with increasing soil depth in both communities, but the difference in δ13C among layers of the top 60 cm soil was significant (p60 cm) was not detected statistically. The changes in δ13C with depth appeared to be associated with the small contribution of residues from Spartina alterniflora at greater soil depth that was directly related to the vertical root distribution of the species.