模拟酸雨对鼎湖山季风常绿阔叶林土壤呼吸的初期影响

发布时间：2018-05-06 12:20

本文选题：模拟酸雨 + 土壤呼吸　；参考：《广西植物》2016年02期

【摘要】：通过在鼎湖山季风常绿阔叶林(季风林)进行野外模拟酸雨试验,对不同酸雨强度处理下的林地土壤呼吸速率进行原位测定,探讨酸雨对南亚热带森林土壤呼吸的初期影响。结果表明:在两年的测定周期内,4个酸雨水平:CK(pH值4.5左右的天然湖水)、T1(pH值4.0)、T2(pH值3.5)和T3(pH值3.0)处理下的年平均土壤呼吸速率分别为(3.07±0.08)、(3.06±0.17)、(2.78±0.29)和(2.56±0.08)μmol·m~(-2)·s~(-1),其中T3处理显著低于CK和T1处理(P0.05),说明模拟酸雨抑制了季风林土壤呼吸。这种抑制作用大体上随处理时间的延长而逐渐显著,处理间的差异只在测定周期的第二年达到显著水平,且抑制作用的差异显著性只出现在湿季(P0.05)。模拟酸雨对土壤呼吸的抑制作用可能与其胁迫下土壤酸化而导致土壤微生物异养呼吸及凋落物CO_2释放量下降有关。表现为模拟酸雨导致土壤pH值降低,使得土壤酸化加剧;降低了土壤微生物量碳、氮含量,抑制了微生物活性;提高了凋落物质量残留率,抑制了凋落物分解。还与土壤呼吸结果相对应,上述指标对模拟酸雨的响应也大体上随处理时间的延长而逐渐显著。另外,土壤呼吸温度敏感系数Q_(10)值随处理pH值降低有下降的趋势,表明酸雨处理在一定程度上降低了土壤呼吸的温度敏感性。
[Abstract]:Field simulated acid rain experiments were conducted in Dinghushan monsoonal evergreen broadleaved forest (monsoon forest) to measure in situ the soil respiration rate of forest land under different acid rain intensities, and to explore the initial effect of acid rain on soil respiration in subtropical forest. The results showed that the annual average soil respiration rates under four acid rain levels (pH 4.5) and T3(pH 3.0) were 3.07 卤0.08 卤3.06 卤0.172.78 卤0.29) and 2.56 卤0.08) 渭 mol / m ~ (-1) ~ (-1) respectively, and T3 treatment was significantly lower than CK and T _ 1 ~ (1). The treatment of P0.05 indicated that simulated acid rain inhibited soil respiration in monsoon forest. The inhibition effect was more and more significant with the prolongation of treatment time, and the difference between treatments reached a significant level only in the second year of the measuring cycle, and the difference of inhibition effect only appeared in the wet season (P0.05). The inhibitory effect of simulated acid rain on soil respiration may be related to soil acidification and the decrease of soil microbial heterotrophic respiration and litter CO_2 release. The results showed that the simulated acid rain led to the decrease of soil pH value, which increased soil acidification; reduced soil microbial biomass carbon, nitrogen content, and inhibited microbial activity; increased litter quality residue rate and inhibited litter decomposition. Corresponding to the soil respiration results, the response of the above indexes to simulated acid rain was more and more significant with the increase of treatment time. In addition, the soil temperature sensitivity coefficient Q _ (10) decreased with the decrease of pH value, indicating that acid rain treatment reduced the temperature sensitivity of soil respiration to a certain extent.
【作者单位】：华南农业大学;中国科学院华南植物园;中国科学院大学;
【基金】：广东省科技计划项目(2014A020216031) 中国博士后科学基金(2014M552207) 国家自然科学基金(31500353,31428001,41430529)~~
【分类号】：S714;X517

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