黄淮海平原不同土地利用方式对土壤有机碳及微生物呼吸的影响

发布时间：2018-03-25 13:23

本文选题：土壤理化性质　切入点：有机碳矿化　出处：《生态环境学报》2017年01期

【摘要】：土壤是陆地生态系统最大的碳库,有机碳通过微生物分解作用向大气释放CO_2,土壤碳库的微小变化将会对大气CO_2浓度和全球碳循环产生巨大的影响。在当前人类活动频繁和土地利用与土地覆被变化的背景下,研究不同土地利用方式对土壤有机碳等理化性质和土壤微生物呼吸等功能的影响,可以阐明影响土壤碳汇功能的关键因子,为未来土地利用管理提供科学依据。以开封市为例,研究了黄淮海平原不同土地利用方式(包括弃耕地、草地、果园、农田和森林)下土壤湿度、pH值、铵态氮、硝态氮、总碳、总氮、有机碳、可溶性有机碳、微生物生物量碳氮、微生物呼吸及其温度敏感性的变化规律。研究结果表明,(1)森林土壤湿度、总碳、总氮、有机碳(1.48%)、微生物生物量碳氮含量显著高于其他土地利用方式,但其微生物呼吸(101.06 mg·kg~(-1)·d~(-1))和温度敏感性(1.18)最小。(2)农田土壤的总碳、总氮、有机碳、微生物生物量碳氮含量均次于森林且高于其他土地利用方式,微生物呼吸速率较大(128.55 mg·kg~(-1)·d~(-1))。(3)弃耕地、草地和果园土壤碳氮和微生物碳氮较小。(4)结构方程模型表明土地利用方式可以直接解释土壤有机碳积累的68%,且可通过土壤湿度间接地影响土壤有机碳和微生物呼吸。土壤有机碳和微生物呼吸分别被土壤湿度和硝态氮含量等因子解释了93%和54%。该研究表明森林生态系统利于土壤有机碳固持,其较小的微生物呼吸温度敏感性对应对未来全球气候变化具有重大意义;农田占地面积广大,农业经营中在保障粮食生产的同时要采取免耕或秸秆还田等措施充分发挥其碳汇作用。
[Abstract]:Soil is the largest carbon pool in terrestrial ecosystems, Organic carbon releases CO-2 into the atmosphere through microbial decomposition, and small changes in the soil carbon pool will have a significant impact on atmospheric CO_2 concentration and the global carbon cycle. In the current context of frequent human activities and land use and land cover changes, To study the effects of different land use modes on soil organic carbon and soil microbial respiration can clarify the key factors affecting soil carbon sequestration function and provide scientific basis for land use management in the future. Taking Kaifeng City as an example, Soil moisture pH, ammonium nitrogen, nitrate nitrogen, total carbon, total nitrogen, organic carbon, soluble organic carbon, microbial biomass carbon under different land use patterns (including abandoned farmland, grassland, orchard, farmland and forest) in Huang-Huai-Hai Plain were studied. The results showed that the soil moisture, total carbon, total nitrogen, organic carbon and organic carbon in forest soil were significantly higher than those in other land use modes. But the microbial respiration (101.06 mg 路kg ~ (-1) 路d ~ (-1)) and the temperature sensitivity (1.18) were the least. 2) the total carbon, total nitrogen, organic carbon and microbial biomass of farmland soil were lower than those of forest and higher than that of other land use patterns. The microbial respiration rate was 128.55 mg 路kg ~ (-1) d ~ (-1). The structural equation model of soil carbon and microbial carbon and nitrogen in grassland and orchard shows that the land use mode can directly explain the accumulation of soil organic carbon, and indirectly affect soil organic carbon and microbial respiration through soil moisture. Soil organic carbon and microbial respiration were accounted for 93% and 54% by soil moisture and nitrate content, respectively. The study showed that forest ecosystems were conducive to soil organic carbon sequestration, Its smaller microbial respiratory temperature sensitivity is of great significance in dealing with future global climate change; farmland covers a large area, In agricultural management, measures such as no-tillage or straw returning to the field should be taken to ensure grain production and give full play to its carbon sequestration.
【作者单位】：河南大学生命科学学院;
【基金】：国家自然科学基金项目(31640011)
【分类号】：S153.6;S154.3

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