title: Effect of nutrient enrichment on the source and composition of sediment organic carbon in tropical seagrass beds in the South China Sea.
abstract: To assess the effect of nutrient enrichment on the source and composition of sediment organic carbon (SOC) beneath Thalassia hemprichii and Enhalus acoroides in tropical seagrass beds, Xincun Bay, South China Sea, intertidal sediment, primary producers, and seawater samples were collected. No significant differences on sediment δ(13)C, SOC, and microbial biomass carbon (MBC) were observed between T. hemprichii and E. acoroides. SOC was mainly of autochthonous origin, while the contribution of seagrass to SOC was less than that of suspended particulate organic matter, macroalgae and epiphytes. High nutrient concentrations contributed substantially to SOC of seagrass, macroalgae, and epiphytes. The SOC, MBC, and MBC/SOC ratio in the nearest transect to fish farming were the highest. This suggested a more labile composition of SOC and shorter turnover times in higher nutrient regions. Therefore, the research indicates that nutrient enrichment could enhance plant-derived contributions to SOC and microbial use efficiency.
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Songlin
authors.initials: S
authors.lastname: Liu
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
authors.forename: Jingping
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yunchao
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; University of Chinese Academy of Sciences, Beijing 100049, China; South China Sea Monitoring Center, State Oceanic Administration, Guangzhou 510300, China.
authors.forename: Zhonglian
authors.initials: Z
authors.lastname: Lian
authors.affiliation: Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China. Electronic address: xphuang@scsio.ac.cn.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Huang
mesh_terms: D061006:Bays; D018533:Biomass; D002244:Carbon / Q000032:analysis*; D002247:Carbon Isotopes / Q000032:analysis; D002681:China; D019015:Geologic Sediments / Q000032:analysis* / Q000737:chemistry; D031321:Hydrocharitaceae / Q000033:anatomy & histology / Q000502:physiology; D059013:Microbial Consortia; D012623:Seawater / Q000032:analysis* / Q000737:chemistry; D014329:Tropical Climate
chemical_list: D002247:Carbon Isotopes; D002244:Carbon
keywords: Composition; Microbial biomass carbon; Nutrient; Seagrass bed; Sediment organic carbon; Source