降雨减少对华北落叶松人工林土壤呼吸的影响

发布时间：2018-06-05 23:33

  本文选题：华北落叶松 + 降雨　； 参考：《生态环境学报》2017年08期

【摘要】：近年来随着降雨格局的变化,区域性干旱加剧,而干旱对土壤碳循环的影响情况仍不十分明确。为探究降雨减少对土壤呼吸的影响,2016年以华北落叶松(Larix principis-rupprechtii)人工林为研究对象,设置对照(CK)、减少降雨30%(W1)和减少降雨60%(W2)3个处理水平,通过人工隔离降雨模拟干旱条件对土壤呼吸速率的影响。在6—10月份生长季,采用LI-8100土壤碳通量测量系统测定每月月中、月末土壤呼吸速率,并同时测定5 cm深度土壤温湿度。结果表明:减少降雨60%使土壤湿度显著降低17.8%(P0.05),而对土壤温度的影响不显著;减少降雨30%对土壤温湿度的影响均不显著;对照、减少降雨30%和减少降雨60%的平均土壤呼吸速率分别为2.45、2.29和2.16μmol·m~(-2)·s~(-1),与对照相比,减少降雨抑制了土壤呼吸,减少降雨60%使平均土壤呼吸速率降低了11.84%(P0.05),土壤呼吸通量减少了41.01 g·m~(-2),而减少降雨30%对土壤呼吸的影响不显著;土壤呼吸速率与土壤温度呈显著指数相关(P0.05),土壤温度解释了66.2%的对照处理的土壤呼吸变异,适当减少降雨能够提高土壤呼吸速率与土壤温度的相关性;在2~7℃土壤温度下,土壤呼吸速率与土壤湿度呈显著二元线性相关(P0.05),且在2~7℃土壤温度下减少降雨提高了土壤呼吸速率和土壤湿度的相关性;在13~17℃土壤温度下,减少降雨则降低了土壤呼吸速率和土壤湿度的相关性;减少降雨提高了土壤呼吸的温度敏感性,且随着降雨减少程度的增大而增大。可见,降雨是影响华北落叶松人工林土壤呼吸的重要因子。
[Abstract]:In recent years, with the change of rainfall pattern, regional drought intensifies, but the effect of drought on soil carbon cycle is still unclear. In order to investigate the effect of rainfall reduction on soil respiration, in 2016, the Larix principis-rupprechtii plantation was used as the research object, and three treatment levels, CK, 30% rainfall and 60% W2, were set up. The effects of drought conditions on soil respiration rate were simulated by artificial rainfall isolation. During the growing season in June-October, the soil respiration rate was measured by LI-8100 soil carbon flux measurement system, and the soil temperature and humidity were measured at a depth of 5 cm. The results showed that the effect of reducing rainfall by 60% on soil moisture was significantly lower than that on soil temperature by 17.8%, but had no significant effect on soil temperature, while the effect of reducing rainfall by 30% on soil temperature and humidity was not significant. The average soil respiration rate of 30% and 60% decreased rainfall was 2.45 ~ 2.29 and 2.16 渭 mol / m ~ (-2) 路s ~ (-1) ~ (-1) ~ (-1), respectively. Compared with the control, the decrease of rainfall inhibited soil respiration. The average soil respiration rate decreased by 11.84% and the soil respiration flux decreased by 41.01 g / m ~ (-2) by 60% rainfall, but the effect of reducing rainfall by 30% on soil respiration was not significant. Soil respiration rate was significantly correlated with soil temperature (P 0.05). Soil temperature explained the variation of soil respiration in 66.2% of the control treatments. Proper reduction of rainfall could increase the correlation between soil respiration rate and soil temperature. There was a significant binary linear correlation between soil respiration rate and soil moisture, and the decrease of rainfall at 2 ~ 7 鈩，

本文编号：1983897