川中丘陵不同土地利用方式下土壤呼吸研究

发布时间：2018-03-18 03:19

本文选题：川中丘陵　切入点：土壤呼吸速率　出处：《四川师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：本研究利用Li-8100土壤呼吸仪测定了川中丘陵三种土地利用方式下土壤呼吸速率的日变化,并同步测定了地下10cm土壤温度、地表温度、大气温度、0-10cm土壤含水率、大气相对湿度、0-10cm土壤的有机碳、全氮、碳氮比、重金属、容重,以期明确不同土地利用方式下土壤呼吸速率日变化的差异,并进一步分析土壤呼吸速率和环境因素的关系。结果表明,在一日内,园地、耕地、荒地土壤呼吸速率都出现了单峰型波动,日平均值的大小具体是:荒地4.76±0.800umol/(m2·s)耕地2.88±0.336umol/(m2·s)园地1.96±0.300umol/(m2·s),差异极显著(P0.01)。园地、耕地、荒地土壤呼吸速率达到峰值时间分别为9:00-11:00、15:00-17:00、13:00-15:00,达到谷值时间分别为5:00-7:00、7:00-9:00、5:00-7:00。土壤呼吸速率的日变化幅度园地(67.86%)荒地(62.39%)耕地(42.36%)。园地、耕地、荒地白天土壤呼吸速率分别是夜间的1.22倍、1.08倍、1.24倍。在大气温度、地表温度和地下10cm土壤温度三个温度层中,地下10cm土壤温度与土壤呼吸速率的相关性最强。园地、耕地的0-10cm土壤含水率与土壤呼吸速率达到了显著性相关(P0.05),荒地0-10cm土壤湿度与土壤呼吸速率达到了极显著性相关(P0.01)。大气湿度与土壤呼吸速率呈现出负相关。本研究选取了指数方程来体现土壤呼吸速率随温度的变化趋势。在园地出现降雨前,土壤呼吸的Q10值均表现为耕地园地荒地。与单因素模型相比,水热复合模型能够更好的模拟土壤温度、湿度和土壤呼吸的相关性。本研究选取了二元线性模型和交互模型拟合土壤温度、水分和土壤呼吸速率的关系,与单因子模型相比,均有所提高。其中二元线性模型拟合效果更好。三种土地利用方式下,有机碳含量、全氮含量、碳氮比的大小顺序均为:园地荒地耕地。耕地和荒地土壤呼吸速率的大小顺序与有机质含量、全氮含量、碳氮比的顺序相同。除园地中Zn的含量达到二级标准外,其他均是一级标准,实验区土壤中重金属含量基本保持在自然背景值水平,未受到重金属污染。土壤呼吸速率与重金属含量相关性不显著。
[Abstract]:In this study, the diurnal variation of soil respiration rate under three land use patterns in hilly area of central Sichuan was measured by Li-8100 soil respiration instrument, and the soil moisture content of 10cm underground soil temperature, surface temperature and atmospheric temperature was measured simultaneously. The soil organic carbon, total nitrogen, ratio of carbon to nitrogen, heavy metal and bulk density of 0-10cm soil with relative humidity of atmosphere were determined in order to determine the diurnal variation of soil respiration rate under different land use patterns. Furthermore, the relationship between soil respiration rate and environmental factors was analyzed. The results showed that in 1st, the soil respiration rate of garden, cultivated land and wasteland had a single peak fluctuation. The diurnal average value is: wasteland 4.76 卤0.800 umolr / m ~ 2 路s) cultivated land 2.88 卤0.336 umolr / / m ~ 2 路s) garden land 1.96 卤0.300 umolr / r ~ (2) m ~ 2 路s ~ (-1), the difference is very significant (P _ (0.01) ~ (-1)). The peak time of soil respiration rate in wasteland is 9: 00-11: 00, 1500-17: 00, 13: 00-1500-15: 00, and the valley time is 5: 00-7: 00, 7: 00-7: 00, 5: 00-7: 00. range of diurnal variation of soil respiration rate. The soil respiration rate in the wasteland during the day was 1.22 times 1.08 times 1.24 times of that in the night, respectively. Among the three temperature layers, atmospheric temperature, surface temperature and underground temperature of 10cm, the correlation between soil temperature and soil respiration rate was the strongest. There was a significant correlation between soil moisture content and soil respiration rate in 0-10cm cultivated land, and a significant correlation between soil moisture content and soil respiration rate in wasteland (0-10cm). There was a negative correlation between atmospheric moisture content and soil respiration rate. This study shows that there is a negative correlation between soil moisture and soil respiration rate. The exponential equation was selected to reflect the variation of soil respiration rate with temperature. Compared with the single factor model, the water and heat composite model can better simulate the soil temperature. In this study, binary linear model and interactive model were selected to fit the relationship between soil temperature, moisture and soil respiration rate, compared with single factor model. Under three land use patterns, organic carbon content, total nitrogen content, organic carbon content, total nitrogen content, total nitrogen content, organic carbon content, total nitrogen content, total nitrogen content, organic carbon content, total nitrogen content, The order of C / N ratio is: garden wasteland cultivated land. The order of soil respiration rate of cultivated land and wasteland is the same as that of organic matter content, total nitrogen content and C / N ratio. Except for Zn content in garden land, the order of soil respiration rate is the same as that of organic matter content, total nitrogen content and carbon nitrogen ratio. The others were first class standard. The content of heavy metals in the soil of the experimental area kept basically at the level of natural background value and was not polluted by heavy metals. The correlation between soil respiration rate and heavy metal content was not significant.
【学位授予单位】：四川师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S154

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