【作者】 米晶晶；

【导师】 武冬梅； 李洪建；

【作者基本信息】 山西大学 ， 自然地理学， 2009， 硕士

【摘要】 土壤呼吸作为表征土壤肥力和土壤质量的生物学指标,在一定程度上反映了生态系统生产力与气候变化的相应关系,对准确估算研究样地土壤CO₂的排放量以及碳贮量的变化具有重要意义。本论文以位于山西省郊城县与方山县交界处的庞泉沟八道沟林场的4个样地为研究对象,通过长期的野外调查和实验室分析,研究了不同类型样地的土壤呼吸及其环境因子（土壤水分,土壤温度,土壤有机碳）的关系以及不同样地土壤呼吸的季节变化和日变化的模式及其机制,对山西高原土壤呼吸及土壤CO₂排放量估算都具有重要的参考价值。本论文分为5部分,第1章为引言,第2章介绍研究区域及研究方法,第3章为主要研究内容,以庞泉沟八道沟林场的4个样地为研究对象,对各样地的土壤温度,土壤水分,土壤有机碳含量及土壤呼吸的季节变化进行分析研究,同时对土壤呼吸与其环境因子之间的关系作出分析,并估算了测定期间的CO₂排放量。以2007年8月,10月,2008年5月至9月为测定期对土壤呼吸日变化进行研究,揭示土壤呼吸昼夜变化的规律。第4,5章对本论文的研究进行讨论及展望。主要研究结果如下:（1）土壤温度的变化具有明显的季节性特征。08年5月至10月期间土壤温度的季节变化基本呈对称的“铃”型趋势,最低温度出现在10月,最高温度主要出现在夏季的7-8月份。07年从8月份开始测定,土壤温度较高,基本在15～20℃之间。之后气温不断下降,土壤温度亦持续下降。土壤水分的变化受土壤类型,植被情况和气温的共同影响。测定期内各样地土壤水分无规律可循,土壤水分含量呈高、低交替变化趋势。在4个样地中,混交林的土壤水分相对较高。这是由于其独特的自然条件以及植被特征,最高含水量达到39.70%。4种样地土壤呼吸和土壤温度的季节变化非常明显,基本趋于一致。说明土壤温度对土壤呼吸的季节变化起主导作用。同时,土壤温度和土壤水分共同作用影响土壤呼吸。2007年9月土壤温度降低,但土壤呼吸仍有上升趋势,这可能是由于水分作用的结果。尤其是混交林和人工林的土壤呼吸值较07年8月高,可能受到水分,植被及坡向的影响。4种样地间的土壤呼吸总体差异不显著（p＞0.05）。土壤有机碳的变化主要受气候、植被和土壤特征以及区域地形的综合影响,本文对07年8,9,10月的4种样地土壤有机碳进行了测定。在测定期内,土壤有机碳没有明显的变化趋势。本次实验测定时间较短,仍在继续测定之中,土壤有机碳的积累没有明显特征,数量差异并不大。（2）对4种样地土壤呼吸和土壤温度,土壤水分,土壤有机碳进行指数关系分析。土壤呼吸和土壤温度的R²值介于0.52-0.80之间,相关性较好。从指数方程P值的检验结果来看,混交林,沙棘及农田样地的土壤呼吸与土壤温度的P值＜0.05,达到显著水平,但人工林样地的P值为0.07,可能是由于土壤温度和土壤水分存在一定程度的相关关系,水分的变化同样影响土壤呼吸。土壤呼吸与土壤水分的相关性较差,R²值得范围在0.00-0.31之间,这主要与庞泉沟地区的气候环境有关。土壤水分含量的大小为:混交林＞人工林＞沙棘＞农田,土壤呼吸与土壤水分的指数模型中的R²值为混交林＞人工林=沙棘＞农田,这表明,土壤含水量越高,土壤呼吸越大。但与土壤呼吸与土壤温度的相关性相比,土壤温度对土壤呼吸的影响大于土壤水分对土壤呼吸的影响。土壤有机碳对土壤呼吸的影响也较为明显。以07年8,9,10月的土壤有机碳和土壤呼吸的测定值进行拟合,结果显示土壤有机碳和土壤呼吸的关系较好,07年9月,10月的R²值分别为0.58和0.65,达到相关水平,07年8月的R²值较小,为不相关,这是因为8月份沙棘的土壤呼吸值较大,可能与沙棘的植被特点有关。（3）土壤呼吸和土壤温度都具有明显的日变化特点,基本表现为单峰曲线。本文测定的4种样地中,以沙棘的土壤呼吸日变化最大,最大值在08年8月份,达到9.12μmol m^-2s^-1,农田的土壤呼吸日变化较小。总体来讲,07年土壤呼吸变化幅度为0.75～5.58μmol m^-2s^-1,08年土壤呼吸变化幅度为1.45～9.12μmol m^-2s^-1,最小值出现在07年10月,最大值出现在08年8月,这仍与土壤温度有密切关系。本文测定的土壤呼吸日变化与土壤温度的变化趋势不太一致,土壤呼吸日变化最大值在11:00-16:00之间,从土壤呼吸与土壤温度的直线关系看,除07年8月和08年8月土壤呼吸与土壤温度变化的关系显著外,其他样地的土壤呼吸与土壤温度的关系均不显著（表3-11）。这可能与各样地的自身环境有关,土壤温度的变化滞后于土壤呼吸的日变化,如土壤呼吸的最大值多出现在10:00-12:00前,而土壤温度的最大值则出现在14:00-15:00。各样地的差异程度见表3-10,除08年5月各样地之间土壤呼吸差异显著外,其它各月各样地之间的土壤呼吸总体差异不显著（p＞0.05）。多数土壤呼吸测定是在白天进行的,但白天土壤呼吸的测定值仍不能代表24h的土壤呼吸值。所以夜间土壤呼吸的估算也很重要。本文以24h的土壤呼吸平均值分别与8:00-12:00、12:00-16:00土壤呼吸的平均值进行比较,在8:00-12:00之间,农田的土壤呼吸平均值高于日平均值10%,而在12:00-16:00之间,混交林的平均值比日平均值高10-20%,沙棘,农田,人工林的平均值高约10%,从测定结果来看,在计算土壤呼吸总量时应当考虑不同时间土壤呼吸值所占的比例大小,否则将影响计算结果。更多还原

【Abstract】 The soil respiration as biology indicators of soil fertility and soil quality, reflects the relationship between ecosystem productivity and climate change to a certain extent. It is also important for us to estimate and research the corresponding relationship between the soil CO₂ emissions and changes in carbon storage. In this paper, the study of Forest badaogou is located in jiaocheng and fangshan of Shanxi Province. Through long-term field investigation and laboratory analysis, we studied the relationship between different types soil respiration and its environmental factors （soil moisture, soil temperature, soil organic carbon） as well as the seasonal variation of soil respiration and diurnal variation in different samples. It has important reference value to soil respiration and soil CO₂ emissions estimation of the plateau of Shanxi. This dissertation consists of five chapters, for the introduction of Chapter 1. The Chapter 2 introduced the study area and research methods, Chapter 3 as the main study to 4 sites plot of studies on various of soil temperature, soil water, soil organic carbon content and the soil respiration of seasonal variation to carry out analytical studies with the relationship between environmental factors to analyze and estimate CO₂ emissions of the period of the determination. To August 2007, 10 months, in May 2008 to September, the determination of diurnal variation of soil respiration to study diurnal variation of soil respiration to reveal patterns. Chapter 4,5 to discuss the research and prospects. The main findings are as follows:（1） The changes of soil temperature has obvious seasonal characteristics. the seasonal variation of soil temperature has "bell" type in May 2008 to October, the minimum temperature in October, the maximum temperature mainly during the summer months 7-8. In august 2007, soil temperature has higher, between in the 15～20℃. After declining temperature, soil temperature has continued to drop.Changes in soil water by the soil type, vegetation and the combined effect of temperature. during the times , soil water content was high-and low-turn trend. In the four sites, the forest’s soil water is relatively high. This is due to its unique natural conditions and vegetation characteristics, the maximum water content reached 39.70%.Four kinds of samples of soil respiration and soil temperature is very obvious seasonal variations, the basic line. Description of soil temperature on the seasonal variation of soil respiration play a leading role. At the same time, soil temperature and soil moisture effects of the combined effect of soil respiration. September 2007 to reduce soil temperature, but there is still an upward trend in soil respiration, which may be due to the result of moisture. Mixed forest and plantations in particular, the value of soil respiration than the August 2007, may be subject to moisture, vegetation and the impact of slope aspect. Four kinds of samples of soil respiration between the overall difference was not significant （p> 0.05）.Changes in soil organic carbon is mainly affected by climate, vegetation and soil characteristics of the combined effects of regional topography, In this paper, the four kinds of soil organic carbon samples were determined in 2007 on august September and October . In the period, the soil organic carbon did not significantly change. Experimental Determination of the shorter, continued determination, and the accumulation of soil organic carbon no obvious features, the number of difference is not significant.（2） The four samples of soil respiration and soil temperature, soil water, soil organic carbon analysis of the relationship between index. Soil respiration and soil temperature between R² between 0.52-0.80, correlation is good. P from the test results, the forest, shaji and farmland of soil respiration and soil temperature of the P value <0.05, reached a significant level, but the plantation plots P of 0.07 may be due to soil temperature and soil moisture there is a certain degree of correlation between changes in water the same impact on soil respiration.Soil respiration and soil water less relevant, R² should be between the range of 0.00-0.31, which mainly related to the climate Pangquangou environment. The size of the soil moisture content as follows: mixed forest> plantation> shaji> farmland, soil respiration and soil moisture index model R2 value of the forest> plantation = shaji > farm, which indicates that the higher soil moisture, the greater the soil respiration. However, soil respiration and soil temperature compared to the correlation of soil temperature on soil respiration than the soil moisture on soil respiration.Soil organic carbon to soil respiration is also more evident. 8,9,10 in 2007 year of soil organic carbon and soil respiration to fit the measured results showed that soil organic carbon and the soil respiration relationship is very good, in September 2007,10 months of R² values were 0.58 and 0.65, to the relevant level, in August 2007 of R2 value of smaller, in order to not relevant, because in August the soil respiration shaji larger value may be related to the characteristics of sea buckthorn on the vegetation.（3） Soil respiration and soil temperature are characterized by significant diurnal variation, the basic performance of a single peak curve. In this paper, the determination of four kinds of samples in order to shaji diurnal variation of soil respiration the most, the maximum value in August 2008 to 9.12μmolm^-2s^-1, farmland smaller diurnal variation of soil respiration. In general, changes in soil respiration in 2007 ranging from 0.75～5.58μmolm^-2s^-1, 08 changes in soil respiration rate to 1.45～9.12μmolm^-2s^-1, the minimum appears in the October 2007, the maximum appears In August 2008, which is still closely related with soil temperature.In this paper, determination of diurnal variation of soil respiration and soil temperature was not so consistent trend, the maximum daily change of soil respiration in between 11:00-16:00 from soil respiration and soil temperature of the linear relationship, except in August 2007 and August 2008 soil respiration and soil temperature changes in the relationship between the significant other kind of soil respiration and soil temperature are not significant （Table 3-11）. This may be related to all sorts of their own environment, soil temperature lags behind the changes in diurnal variation of soil respiration, such as the maximum number of soil respiration in the 10:00-12:00 ago, and while the maximum soil temperature in the 14:00-15:00. Differences in the degree of variety in Table 3-10, with the exception of May 2008 between the various significant difference between soil respiration, the other on all sorts of soil respiration between the overall difference was not significant （p> 0.05）.Determination of soil respiration to provide an accurate quantification of soil CO₂ emissions. However, determination of the majority of soil respiration is carried out in the daytime, so how the estimates of soil respiration at night it is particularly important. In this paper, 24 h average of soil respiration, respectively, the average soil respiration 8:00-12:00,12:00-16:00 compared 8:00-12:00 fields of soil respiration on average than the average 10%, while the average of 12:00-16:00, the mixed forest than the average of 10-20% on average high, sea buckthorn, farms, plantations on average about 10%, so in the calculation of total soil respiration should be taken into account, otherwise, if the value of the morning or afternoon as the value of soil respiration on the calculation results may too.更多还原