热带香蕉园地土壤呼吸变化特征及其与环境因子的关系

Soil Respiration in A Tropical Banana Plantation and Its Relation to Environmental Factors

香蕉园是海南重要的农田生态系统类型。为了探明香蕉园地土壤呼吸的变化特征及其与环境因子之间的关系,2016年11月—2017年10月运用LI-8100A土壤呼吸测量系统对海南澄迈香蕉园地行间与株间的土壤呼吸进行系统监测分析。结果表明:香蕉园地行间、株间土壤CO_2通量日变化均呈现出昼高夜低的特点,但株间土壤CO_2通量日最大值出现时间较行间要晚1.5 h左右,株间土壤CO_2通量高于行间,二者之间存在显著差异(p <0.05);香蕉园地月尺度行间与株间的土壤CO_2通量均存在显著差异(p <0.05),行间各月土壤CO_2通量均值为1.17～2.19μmol·(m^2·s)^(-1),而株间为2.02～5.96μmol·(m^2·s)^(-1);日尺度香蕉园地行间土壤CO_2通量与土壤温度、大气温度、土壤体积含水量存在极显著正相关关系(p <0.01),株间土壤CO_2通量与土壤温度、大气温度存在极显著正相关关系(p <0.01),与土壤体积含水量相关性不显著(p> 0.05);月尺度土壤温度对行间土壤CO_2通量变化有显著影响(p <0.05),香蕉植株生长对株间土壤CO_2通量变化影响显著(p <0.01),而其他因子的影响均未达到显著水平。研究结果丰富了热带农田土壤CO_2通量研究资料,为热带农田土壤碳源–汇的准确评估提供了数据支持。

Banana plantation is an important type of agro-ecosystem in Hainan. To reveal the temporal and spatial variations of soil respiration in banana plantations and its relationship with environmental factors, the experiment was conducted to monitor soil CO2 fluxes of sampling sites in rows(between plants) and between rows in banana plantations by LI-8100 soil CO2 flux system from November 2016 to October 2017 in Chengmai, Hainan. The results showed that the soil CO2 fluxes was high during the day and low at night in rows and between rows, and the soil CO2 fluxes in rows were higher than that between rows at the same time, and the difference was significant in banana plantations(p < 0.05). The maximal soil CO2 flux appeared about 1.5 hours later in rows than that between rows. There was a significant difference in soil CO2 fluxes between rows and between plants on the scale of month in the banana plantations(p < 0.05). The average soil CO2 flux was1.17 to 2.19 μmol·(m^2·s)^-1 in each month between rows, and it was 2.02 to 5.96 μmol·(m^2·s)^-1 between plants. Under the day scale, there was a significant positive correlation between soil CO2 flux and soil temperature, atmospheric temperature,and soil water(p < 0.01) between rows in banana plantations. There was also a significant positive correlation between soil CO2 flux and soil temperature and atmospheric temperature(p < 0.01), and the correlation with soil water was not significant(p > 0.05). Under the month scale, the soil temperature had a significant effect on the soil CO2 flux between the rows(p <0.05), and the growth of banana plant had a significant effect on the CO2 flux of the soil between the plants(p < 0.01). But the effects of other factors did not reach significant levels(p > 0.05). The results of this study indicated the relationship between soil CO2 flux and environmental factors in tropical banana fields, and enriched the CO2 flux research data of tropical farmland, and provided data support for accurate assessment of soil carbon source-sinks in tropical farmland.