论文标题:黄河源区“黑土型”退化高寒草地CO_2、CH_4排放特征研究
The Primary Study on CO_2 and CH_4 Emission from Soil-Plant Systems of "Black Soil Patch" Degraded Alpine Meadow in the Source Area of Yellow River
论文作者
论文导师 龙瑞军,论文学位 硕士,论文专业 草业科学
论文单位 甘肃农业大学,点击次数 74,论文页数 50页File Size1355K
2007-05-20论文网 http://www.lw23.com/lunwen_16797347/
The source area of Yellow River;; alpine meadow;;‘Black soil patch’degraded alpine meadow;; the CO_2 emission rate;; the CH_4 emission rate
采用静态箱-气相色谱法,对黄河源区“黑土型”退化高寒草地的植被-土壤系统CO_2、CH_4释放特征进行了研究,并与地表温度、5cm地温、土壤含水量及地上生物量进行了相关分析,结果表明: 1.“黑土型”退化高寒草地不同处理(植被—土壤、土壤和土壤微生物)CO_2释放速率日变化均呈现出单峰曲线,其最大释放速率出现在15:00前后,最小值出现在4:00前后,4:00至15:00 CO_2释放速率呈上升趋势,15:00至次日4:00呈下降趋势。CO_2释放速率亦具有明显的季节动态,且三个处理的变化趋势基本一致,从7月初逐渐增加,至8月中上旬CO_2释放速率达到最高峰,此后开始下降。三个处理均表现为正排放,观测期内, CO_2释放速率为植物-土壤>土壤>土壤微生物,三个处理平均值分别为460.41±167.74、327.97±108.61和238.44±94.50 mg(/m2·h)。“黑土型”退化高寒草地植物及其地上、地下部分CO_2释放速率亦具有明显的季节动态,从7月初到8月中上旬一直处于上升趋势,此后突然下降,在9月初有所回升,接着继续下降。 2.“黑土型”退化高寒草地不同处理(植被—土壤、土壤和土壤微生物)CH_4释放速率的日变化动态与季节动态均不明显,绝大部分时间处于吸收CH_4状态。在观测期间, CH_4释放速率为植物-土壤>土壤>土壤微生物,平均值分别为-28±26、-38±21和-43±25 ug/(m2·h)。“黑土型”退化高寒草地植物及地上、地下部分CH_4释放速率的季节动态变化不显著。在观测期间,除个别观测日外,三个处理均表现为正排放,释放速率为植物体>地上部分>地下部分。 3.植被—土壤系统、土壤和土壤微生物的CO_2释放速率与地表温度具有极显著正相关关系,相关系数分别为0.907、0.877和0.928。与5 cm地温也具有极显著正相关性,相关系数分别为0.811、0.813和0.968。植被—土壤系统、土壤CO_2释放速率与各层土壤水分相关性均不明显,而土壤微生物的CO_2释放速率与0～10 cm土壤水分含量相关显著,显著系数0.670。植物地上部分CO_2释放速率与地上生物量具有显著正相关关系,相关系数为0.987。 4.植被—土壤系统CH_4释放速率与地表温度相关性不显著,土壤和土壤微生物的CH_4释放速率与地表温度具有显著正相关关系,相关系数分别为0.694和0.705。土壤微生物的CH_4释放速率与5 cm地温具有显著正相关关系,相关系数为0.698。除此以外,植被—土壤系统和土壤的CH4释放速率与5 cm地温相关性不显著。植被—土壤系统CH4释放速率与0～10 cm土壤水分含量相关性极显著,显著系数为0.949,与10～20 cm土壤水分含量显著相关,显著系数0.741,与20～30 cm土壤水分含量相关性不显著。
Using static chamber-GC method,a primary study on CO2 emission and CH4 emission from Soil-Plant Systems of‘Black soil patch’degraded alpine meadow and the relevant analysis of CO2 and CH4 emission with soil surface temperature,5 cm depth soil temperature, soil water content indicated that: 1. The diurnal variation of CO2 emission rate of three different treatments of‘Black soil patch’degraded alpine meadow—the respiration rate of soil -plant system(BC),Soil respiration rate(BJ) and Soil microbial respiration rate (BL) were similar. They all had the evident characteristics of "unimodal curve". The maximum rate appeared around 15:00, and the minimum rate appeared around 4:00.The CO2 emission rate presented the ascending tendency from 4:00 to 15:00 and it dropped from 15:00 to 4:00 of the next day. Seasonal dynamic of the CO2 emission rate was pretty remarkable,and the trend of three different treatments were consistent. The CO2 emission rate increased gradually from the beginning of July to the middle of August, and and it dropped down. The CO2 emission rate given off,did not absorb. In the period of observation, the CO2 emission rate varied with different treatments showing an order of BC>BJ>BL,and the average rates were 460.41±167.74、327.97±108.61 and 238.44±94.50 mg/(m2·h). Seasonal dynamic of the CO2 emission rate of plants, overground part of plants and underground part of plants were pretty distinct. The CO2 emission rate increased gradually from the beginning of July to the middle of August, and it dropped down swift later, it went on rising in the beginning of September and continued to drop finally. 2. The both of the diurnal variation and seasonal dymanic of the CH4 emission rate of three different treatments of‘Black soil patch’degraded alpine meadow were not prominent. CH4 emission is at the absorption condition in a great measure time. In the experiment perio,the CH4 emission rate varied with different treatments showing an order of BC>BJ>BL, and their average rates were -28±26、-38±21 and -43±25 ug/(m2·h). Seasonal dynamic of the CH4 emission rate of plants,overground part of plants and underground part of plants were not pretty distinct. The CH4 emission rate was positive. The CH4 emission rate indicated plants > overground part of plants > underground part of plants. 3. There was a extreme significant correlation between soil surface temperature and the CO2 emission rate of soil -plant system(BC),soil respiration rate(BJ) and soil microbial respiration rate (BL) of‘Black soil patch’degraded alpine meadow. The correlation coefficients were 0.907,0.877 and 0.928. There was a extreme significant correlation between soil temperature at 5cm depth and the CO2 emission rate of soil -plant system(BC),Soil respiration rate(BJ) and Soil microbial respiration rate (BL) of‘Black soil patch’degraded alpine meadow. The correlation coefficients were 0.811、0.813 and 0.968. The correlation between the CO2 emission rate of soil -plant system and 10~20 cm , 20~30cm soil water content was not significant. But there existed a significant correlation between the CO2 emission rate of soil–plant system and 0~10cm soil water content. The correlation coefficient was 0.670. There was a significant correlation between the CH4 emission rate of over ground part of plants and aboveground phytomass. The correlation coefficient was 0.987. 4. The correlation between soil surface temperature and the CH4 emission rate of soil -plant system (BC) was not significant. There was a significant correlation between soil surface temperature and the CH4 emission rate of soil respiration rate(BJ) and soil microbial respiration rate (BL) of‘Black soil patch’degraded alpine meadow. The correlation coefficients were 0.694,0.705. There was an extreme significant correlation between soil temperature at 5cm depth and the CH4 emission rate of Soil microbial respiration rate (BL) of‘Black soil patch’degraded alpine meadow. The correlation coefficient was 0.698. There existed an extreme significant correlation between the CH4 emission rate of soil -plant system and 0~10cm soil water content. The correlation coefficient was 0.949. There existed a significant correlation between the CH4 emission rate of soil -plant system and 10~20cm soil water content. The correlation coefficient was 0.741.The correlation between the CH4 emission rate of soil -plant system and 20~30 cm soil water content was not significant.
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