植物生态学报 ›› 2015, Vol. 39 ›› Issue (7): 674-681.DOI: 10.17521/cjpe.2015.0064

• 研究论文 • 上一篇    下一篇

不同来源可溶性有机物对亚热带森林土壤CO2排放的影响

万菁娟, 郭剑芬*(), 纪淑蓉, 任卫岭, 司友涛, 杨玉盛   

  1. 福建师范大学地理科学学院, 湿润亚热带山地生态国家重点实验室培育基地, 福州 350007
  • 出版日期:2015-07-01 发布日期:2015-07-22
  • 通讯作者: 郭剑芬
  • 作者简介:

    *作者简介:E-mail:dengchuanyuan@163.com

  • 基金资助:
    国家自然科学基金(31370615、31130013和31470501)、国家重大科学研究计划课题(2014CB954003)和福建省教育厅重点项目(JA13065)

Effects of different sources of dissolved organic matter on soil CO2 emission in subtropical forests

WAN Jing-Juan, GUO Jian-Fen*(), JI Shu-Rong, REN Wei-Ling, SI You-Tao, YANG Yu-Sheng   

  1. State Key Laboratory Breeding Base of Humid Subtropical Mountain Ecology, College of Geographical Sciences, Fujian Normal University, Fuzhou, 350007, China
  • Online:2015-07-01 Published:2015-07-22
  • Contact: Jian-Fen GUO
  • About author:

    # Co-first authors

摘要:

采用室内培养法, 比较分析了亚热带地区杉木(Cunninghamia lanceolata)和米槠(Castanopsis carlesii)鲜叶及凋落叶浸提得到的可溶性有机物(dissolved organic matter, DOM)组成和化学性质差异对土壤CO2排放的影响。结果表明: 添加不同来源的DOM后, 土壤CO2瞬时排放速率在培养第1天内均显著高于对照(添加去离子水) (p < 0.05), 分别比对照增加了91.5% (添加杉木鲜叶DOM)、12.8% (添加米槠鲜叶DOM)、61.0% (添加杉木凋落叶DOM)和113.3% (添加米槠凋落叶DOM), 但培养5天后, 分别下降到对照的24.1%、8.3%、14.6%和13.2%, 随后逐渐趋于平稳。单次添加外源DOM到土壤中, 引起土壤CO2排放速率增加的强度较大, 但持续时间短暂。培养31天时, 添加不同来源的DOM均对土壤CO2累积排放量具有显著影响(p < 0.05), 而在培养59天时, 添加杉木鲜叶和凋落叶DOM的土壤CO2累积排放量均显著高于添加米槠鲜叶和凋落叶DOM的土壤CO2累积排放量, 但添加相同树种鲜叶与凋落叶DOM的土壤CO2累积排放量之间差异不显著。培养结束后, 添加杉木鲜叶DOM和杉木凋落叶DOM后增加的土壤碳排放量, 分别是外源添加可溶性有机碳量的1.76倍和2.56倍, 而添加米槠鲜叶DOM和米槠凋落叶DOM后增加的土壤碳排放量只占外源添加可溶性有机碳量的22.5%和50.0%, 表明单次添加不同来源的DOM对土壤总有机碳库的影响是不一致的。

关键词: 碳矿化, 米槠, 杉木, 可溶性有机物, 鲜叶, 凋落叶

Abstract: Aims Dissolved organic matter (DOM) is an important carbon and nutrient pool, but the effects of different sources of DOM on soil carbon cycling are less well understood. Our objective in this study was to investigate how differences in the quantity and quality of DOM from fresh leaves and leaf litter of Cunninghamia lanceolata and Castanopsis carlesii affected soil CO2 fluxes in a laboratory incubation experiment. Methods Mineral soils (0-10 cm) from an 11-year-old Cunninghamia lanceolata plantation in Sanming of Fujian Province, China, were incubated for 59 days after adding the DOM from fresh leaves and leaf litter of Cunninghamia lanceolata and Castanopsis carlesii. Carbon (C) mineralization during incubation was determined using CO2 respiration method. Important findings Compared to the controls, the rates of C mineralization significantly increased by 91.5%, 12.8%, 61.0% and 113.3% on day 1, following additions of DOM from fresh leaves and leaf litter of Cunninghamia lanceolata and Castanopsis carlesii, respectively; the magnitudes of the increases declined to 24.1%, 8.3%, 14.6% and 13.2% by day 5, indicating that addition of DOM had significant but short-term influences on soil CO2 emission. DOM from different sources had significant effects on the cumulative CO2 production following addition of DOM by day 31 (p < 0.05). After 59 days of incubation, the cumulative quantity of mineralized C following addition of DOM from fresh leaves and leaf litter of Cunninghamia lanceolata was significantly greater than that from those of Castanopsis carlesii, while there was no significant difference in the cumulative CO2 production between DOM from fresh leaves and leaf litter of the same tree species, suggesting that difference in tree species had a greater influence on C mineralization than difference in the degree of leaf decay. Addition of DOM originated from fresh leaves and leaf litter of Castanopsis carlesii resulted in increased C mineralization by 22.5% and 50.0% of C added over the course of 59 day incubation, whereas increases by additions of DOM from fresh leaves and leaf litter of Cunninghamia lanceolata were 1.76 times and 2.56 times, respectively. Thus, a single addition of different sources of DOM may lead to diverse effects on total soil carbon stocks.

Key words: C mineralization, Castanopsis carlesii, Cunninghamia lanceolata, dissolved organic matter, fresh leaves, leaf litter