| 摘要: |
| 【目的】研究常绿阔叶林恢复演替过程对土壤微生物量碳、氮及微生物活性的影响。【方法】从湖南鹰嘴界代表常绿阔叶林不同演替阶段的马尾松林(PF)、针阔混交林(MF)、常绿阔叶林(BF)样地上、中、下坡挖取土壤剖面，按0～10和10～20 cm分层采集土壤样品，测定土壤微生物生物量碳（Cmic）、氮（Nmic）及土壤基础呼吸、土壤有机碳（SOC）和全氮(TN)，以分析常绿阔叶林不同演替阶段的土壤微生物量碳、氮及微生物活性。【结果】随着常绿阔叶林演替递进，0～10 cm 土层土壤SOC由20.29 g/kg增至41.96 g/kg，TN由1.18 g/kg增至2.33 g/kg，Cmic由448.62 mg/kg增至1 021.95 mg/kg，Nmic由35.21 mg/kg增至109.62 mg/kg，土壤基础呼吸由1.12 mg/(kg·h)增加到1.36 mg/(kg·h)，代谢熵（qCO2）由2.51 mg/(g·h)降低到1.33 mg/(g·h)。由相关分析可知，Cmic、Nmic均与 SOC和TN显著正相关；微生物熵（Cmic/SOC）在PF中最低，MF中次之，BF中最高，且与SOC、TN存在显著的负相关性，与Cmic、土壤微生物量碳氮比存在显著正相关；土壤基础呼吸与SOC、TN和Cmic存在显著的正相关性；代谢熵与SOC、Cmic、Nmic有极显著负相关关系。【结论】研究区内植被演替可使土壤微生物生物量增加、土壤肥力改善。凋落物输入质量的改善、土壤肥力的提高，是中亚热带常绿阔叶林微生物量碳、氮和微生物熵随演替进程逐渐增大的主要原因。通过封山育林、择伐等经营措施，可以促进针叶林向常绿阔叶林递进和森林土壤肥力恢复。 |
| 关键词: 常绿阔叶林 土壤微生物量 微生物活性 中亚热带 |
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| 基金项目:科技部国际科技合作专项(2015DFA90450)；中科院先导科技专项 (XDA05050205)；湖南省自然科学基金项目(2015JJ6050)；湖南省林业科技计划项目(XLK201417，XLGYLCJ 201501)；湖南省林业科学院科研创新基金项目(2013LQJ08)；世界银行贷款湖南森林恢复与发展项目（JC-3） |
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| Biomass and activity of soil microbes in evergreen broad-leaf forests at different succession stages in Yingzuijie |
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ZENG Zhangquan,WANG Silong,ZHANG Canming,et al
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| Abstract: |
| 【Objective】This study investigated the effects of forest succession on soil microbial biomass and activity. 【Method】 The soil samples were collected at the layers of 0-10 cm and 10-20 cm from uphill,middle slope and downhill of pine (Pinus massoniana) forest (PF),pine and broadleaf mixed forest (MF) and evergreen broadleaf forest (BF) representing different succession stages of evergreen broad leaf forest in the Yingzuijie Biosphere Reserve,Hunan,China.Biomass carbon (Cmic),nitrogen (Nmic),soil respiration,soil organic carbon (SOC) and total nitrogen (TN ) were measured and compared.【Result】 During the succession from PF,MF to BF,SOC,TN,Cmic,Nmic and soil respiration in layer of 0-10 cm increased from 20.29 g/kg to 41.96 g/kg, 1.18 g/kg to 2.33 g/kg,448.62 mg/kg to 1 021.95 mg/kg,35.21 mg/kg to 109.62 mg/kg,and 1.12 mg/(kg·h) to 1.36 mg/(kg·h),while qCO2 decreased from 2.51 mg/(g·h) to 1.33 mg/(g·h).Correlation analysis showed that Cmic and Nmic were strongly correlated to SOC and TN. Contribution of Cmic to SOC (Cmic/SOC) was the lowest in PF,and was significantly and negatively correlated to SOC,TN，and strongly correlated to Cmic and Cmic/Nmic.Soil respiration was strongly correlated with SOC,TN and Cmic.The qCO2 was significantly and negatively correlated to SOC,Cmic and Nmic.【Conclusion】 Succession from PF,MF to BF resulted in increase in biomass and soil fertility of soil microbes.The quality of litter and the improvement of soil fertility were the main reason for the increase of microbial biomass with the succession.Forest management practices such as enclosures and selective cutting could accelerate the succession of coniferous forest into evergreen broad leaved forest and restore soil fertility. |
| Key words: evergreen broad-leaf forest soil microbial biomass microbial activity mid-subtropical region |
