Effects of seagrass leaf litter decomposition on sediment organic carbon composition and the key transformation processes  

作　　者：LIU SongLin JIANG ZhiJian DENG YiQin WU YunChao ZHAO ChunYu ZHANG JingPing SHEN Yuan HUANG XiaoPing 

机构地区：[1]Key Laboratory of Tropical Marine Bio-resources and Ecology,South China Sea Institute of Oceanology,Chinese Academy of Sciences [2]College of Earth Science,University of Chinese Academy of Sciences [3]South China Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences

出　　处：《Science China Earth Sciences》2017年第12期2108-2117,共10页中国科学（地球科学英文版）

基　　金：supported by the National Basic Research Program of China(Grant Nos.2015CB452905,2015CB452902);the National Natural Science Foundation of China(Grant Nos.41730529,41306108,41406128);the National Specialized Project of Science and Technology(Grant No.2015FY110600)

摘　　要：Seagrass leaf litters are an important source of sediment organic carbon(SOC). However, the mechanisms of seagrass leaf litter decomposition influencing SOC composition and the key transformation processes remain unknown. We performed a laboratory chamber experiment to compare the labile organic carbon(OC) composition and the enzyme activities governing SOC transformation between the seagrass group(seagrass leaf litter addition) and the control group. The results showed that the seagrass leaf litter decomposition significantly elevated the salt-extractable carbon(SEC) content and the SEC/SOC. Additionally,the levels of invertase, polyphenol oxidase, and cellulase in the seagrass leaf litters addition group were generally higher than in the control group, which could elevate recalcitrant OC decomposition. Following 24 days incubation, addition of seagrass leaf litter increased the amount of CO_2 released, but decreased the SOC content. Therefore, seagrass leaf litter decomposition leached abundant dissolved OC, which enhanced the activity and transformation of SOC.Seagrass leaf litters are an important source of sediment organic carbon（SOC）. However, the mechanisms of seagrass leaf litter decomposition influencing SOC composition and the key transformation processes remain unknown. We performed a laboratory chamber experiment to compare the labile organic carbon（OC） composition and the enzyme activities governing SOC transformation between the seagrass group（seagrass leaf litter addition） and the control group. The results showed that the seagrass leaf litter decomposition significantly elevated the salt-extractable carbon（SEC） content and the SEC/SOC. Additionally,the levels of invertase, polyphenol oxidase, and cellulase in the seagrass leaf litters addition group were generally higher than in the control group, which could elevate recalcitrant OC decomposition. Following 24 days incubation, addition of seagrass leaf litter increased the amount of CO_2 released, but decreased the SOC content. Therefore, seagrass leaf litter decomposition leached abundant dissolved OC, which enhanced the activity and transformation of SOC.

关 键 词：Seagrass leaf litter Sediment organic carbon COMPOSITION Enzyme activities 

分 类 号：Q948[生物学—植物学]