氮沉降和降水变化对华西雨屏区天然常绿阔叶林土壤呼吸的影响

发布时间：2018-02-28 22:34

本文关键词： 氮沉降降雨土壤呼吸天然常绿阔叶林　出处：《西北农林科技大学学报(自然科学版)》2017年04期 　论文类型：期刊论文

【摘要】：【目的】探究氮沉降和降雨变化对华西雨屏区天然常绿阔叶林土壤呼吸的影响。【方法】通过野外原位试验,设置氮沉降(N)、减少降雨(R)、增加降雨(W)和对照(CK)4个处理,对天然常绿阔叶林土壤呼吸速率、0~10cm土层土壤温度和土壤体积含水量进行为期1年的观测,并对以上3项指标的相关性进行分析,然后在试验处理的第13个月测定微生物生物量C、N含量。【结果】(1)N、R和W处理的平均土壤呼吸速率分别比CK降低了29.53%,12.26%和21.18%,各处理均显著抑制了常绿阔叶林土壤呼吸速率(P0.05)。(2)N、R、W和CK的土壤呼吸年通量分别为1 489.85,1 854.85,1 666.32和2 114.11g/m2,N、R和W处理均显著减少了土壤呼吸年通量(P0.05)。(3)N、R、W和CK的Q_(10)(土壤呼吸对温度的敏感系数)值分别为2.37,2.98,2.43和2.53。减少降雨可能使土壤呼吸的温度敏感性升高,氮沉降和增加降雨则降低了土壤呼吸的温度敏感性。(4)分别采用指数模型和一元二次项方程拟合土壤呼吸速率与温度和体积含水量间的回归方程,表明土壤温度能解释土壤呼吸月动态变化的83.08%~94.67%,土壤体积含水量能解释土壤呼吸月动态变化的63.06%~67.30%。(5)与CK相比,N、R、W处理的微生物生物量C、N含量均显著降低。【结论】氮沉降、增加降雨和减少降雨处理均显著抑制了华西雨屏区天然常绿阔叶林的土壤呼吸。在模拟氮沉降和降水变化下,与土壤水分相比,土壤温度是该区常绿阔叶林土壤呼吸的主要影响因素。
[Abstract]:[objective] to investigate the effect of nitrogen deposition and rainfall change on soil respiration of natural evergreen broadleaved forest in Yuping area of West China. The soil respiration rate of natural evergreen broadleaved forest was measured for one year in 10 cm soil layer, and the correlation of the above three indexes was analyzed. Then, the microbial biomass C N content was measured in the 13th month of the experiment. [results] the average soil respiration rate of the treatment with N and W decreased by 29.53% 12.26% and 21.18%, respectively, compared with CK. All treatments significantly inhibited the soil respiration rate of evergreen broad-leaved forest. The annual soil respiration fluxes were 1 489.85U 1 854.85U 1 666.32 and 2 114.11g / m 2N 2 N R and W treatments significantly decreased the annual soil respiration fluxes (P 0.05 N N RW and CK values of 2.372.982.43 and 2.53, respectively). The annual soil respiration fluxes were 2.372.982.43 and 2.53, respectively, and the annual soil respiration fluxes were 2.372.982.43 and 2.53, respectively. The annual soil respiration fluxes were 2.372.982.43 and 2.53, respectively, and the annual soil respiration fluxes were 2.372.982.43 and 2.53, respectively. The results showed that the annual soil respiration fluxes were 2.372.982.43 and 2.53, respectively. The temperature sensitivity of soil respiration is increased, The temperature sensitivity of soil respiration was reduced by nitrogen deposition and increasing rainfall. The exponential model and the quadratic equation were used to fit the regression equation between soil respiration rate and temperature and volume water content, respectively. The results showed that the soil temperature could explain the monthly dynamic changes of soil respiration, and the soil volumetric water content could explain the dynamic changes of soil respiration month. 63.060.30. 5) compared with CK, the microbial biomass (Con N) of NRW treatment was significantly lower than that of CK. [conclusion] nitrogen deposition. The soil respiration of natural evergreen broad-leaved forest was significantly inhibited by increasing rainfall and decreasing rainfall. Under the simulated nitrogen deposition and precipitation changes, the soil moisture content of the natural evergreen broad-leaved forest was compared with that of soil moisture. Soil temperature is the main influencing factor of soil respiration in evergreen broadleaved forest.
【作者单位】：四川农业大学林学院;
【基金】：国家“十二五”科技支撑计划项目(2010BACO1A11) 四川省“十二五”农作物育种攻关项目(2011NZ0098-10)
【分类号】：S714

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