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应用生态学报 ›› 2021, Vol. 32 ›› Issue (3): 825-835.doi: 10.13287/j.1001-9332.202103.008

• 研究论文 • 上一篇    下一篇

亚热带典型森林地上和地下凋落物输入对土壤新老有机碳动态平衡的影响

洪小敏1, 魏强1, 李梦娇1, 余坦蔚1, 严强2, 胡亚林1*   

  1. 1福建农林大学林学院, 森林生态-稳定同位素研究中心, 福州 350002;
    2福建农林大学西芹教学林场, 福建南平 353001
  • 收稿日期:2020-09-29 接受日期:2020-12-29 出版日期:2021-03-15 发布日期:2021-09-15
  • 通讯作者: * E-mail: huyl@iae.ac.cn
  • 作者简介:洪小敏, 女, 1995年生, 硕士研究生。主要从事森林碳循环研究。E-mail: hhongxm@163.com
  • 基金资助:
    国家自然科学基金项目(U1805243,42077094)资助

Effects of aboveground and belowground litter inputs on the balance of soil new and old organic carbon under the typical forests in subtropical region

HONG Xiao-min1, WEI Qiang1, LI Meng-jiao1, YU Tan-wei1, YAN Qiang2, HU Ya-lin1*   

  1. 1Forest Ecology & Stable Isotope Center, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350002, China;
    2Xiqin Forestry Station of Fujian Agriculture and Forestry University, Nanping 353001, Fujian, China
  • Received:2020-09-29 Accepted:2020-12-29 Online:2021-03-15 Published:2021-09-15
  • Contact: * E-mail: huyl@iae.ac.cn
  • Supported by:
    National Natural Science Foundation of China (U1805243, 42077094)

摘要: 凋落物是森林土壤有机碳(SOC)形成、稳定和周转的重要影响因子。目前针对亚热带不同类型森林地上和地下凋落物对新SOC累积和老SOC输出动态平衡的影响仍不清楚。本研究以中亚热带常绿阔叶天然林、马尾松人工林和杉木人工林为对象,基于C3/C4植物-土壤置换试验,利用稳定同位素13C示踪方法开展3年野外定位试验,分析了森林地上、地下凋落物输入对SOC周转的影响。结果表明: 森林类型、凋落物处理和时间均能显著影响SOC含量、土壤δ13C值、新SOC和老SOC含量,且存在显著的森林类型×凋落物处理交互效应。地上和地下凋落物输入均能显著提高SOC含量和净增量,与杉木人工林相比,天然林SOC对凋落物输入的响应更敏感。凋落物输入显著降低了土壤δ13C值,且天然林、马尾松人工林土壤δ13C显著低于杉木人工林。在马尾松人工林,地下凋落物处理的新SOC含量显著高于地上凋落物;在天然林和马尾松人工林,地下凋落物输入处理的老SOC含量显著低于地上凋落物处理。此外,地上凋落物归还量和地下根生物量与SOC含量和净增量呈显著正相关,而地下根凋落物量和C/N与新SOC含量呈显著正相关。森林地下凋落物比地上凋落物输入对SOC周转的影响更重要,且不同森林凋落物输入对SOC的影响存在差异性。本研究可为揭示亚热带典型森林土壤有机碳库的形成和可持续管理提供依据。

关键词: 亚热带森林, 凋落物输入, 土壤有机碳, 稳定性碳同位素, 土壤有机碳周转

Abstract: Litter is one of the most important factors controlling the accumulation, stabilization, and turnover of soil organic carbon (SOC) in forests. There is a knowledge gap of the impacts of aboveground and belowground litter inputs on the balance of new and old SOC under different forests in subtropical region. We examined the effects of aboveground and belowground litter inputs on SOC turnover using isotopic tracing technique, based on a 3-year C3 plants/C4 soil replacement experiment in natural forest (NF), Masson pine (Pinus massoniana) plantation (PM) and Chinese fir (Cunninghamia lanceolata) plantation (CL). Our results showed that forest types, litter treatments, and sampling time significantly affected SOC contents, δ13C, new and old SOC contents. Moreover, there were significant interactions between forest types and litter treatments. Litter input increased SOC content and net SOC increment, with higher sensitivity of NF than CL. Litter inputs decreased soil δ13C, with lower values in NF and PM compared to CL. For PM, the new SOC content in belowground litter treatment was significantly higher than that in aboveground litter treatment. The contents of old SOC were lower in belowground litter treatment than aboveground litter treatment in the NF and CL. Above- and below-ground biomass were positively correlated with SOC content and net increment. Belowground litter biomass were positively correlated with soil C/N ratio and new SOC content. Our results implied that belowground litter input had stronger effects on SOC turnover compared to aboveground litter input, with the effects varying among different forests. Our results provided new information on SOC accumulation and on sustainable management of the typical forests in subtropical region.

Key words: subtropical forest, litter input, soil organic carbon, 13C stable isotope, soil organic carbon turnover