鸡公山麻栎林和水杉林不同凋落物处理下土壤呼吸对降雨强度的响应

发布时间：2018-07-22 12:43

【摘要】：降雨脉冲对土壤呼吸具有瞬间的激发效应,地表凋落物是土壤有机碳的重要来源,并影响降雨的下渗过程和土壤含水量。降雨对土壤呼吸的激发效应是否受地表凋落物的影响?这一问题目前尚不清楚。针对我国亚热带-暖温带气候过渡区麻栎(Quercus acutissima)林和水杉(Metasequoia glyptostroboides)林2种林型开展不同凋落物输入水平(对照、添加凋落物和去除凋落物)下模拟降雨事件对土壤呼吸影响研究,以阐明不同凋落物条件下土壤呼吸对降雨脉冲的响应规律。结果表明:就麻栎次生林而言,对照、添加凋落物和去除凋落物处理土壤呼吸速率在降雨10 min时均达到峰值,分别为4.72、11.68和5.12μmol·m~(-2)·s~(-1),添加凋落物增强了降雨脉冲的激发效应,去除凋落物与对照处理土壤呼吸速率在降雨事件后无显著差异(P0.05)。地表凋落物层对麻栎次生林在降雨后的土壤呼吸速率变化具有重要影响。水杉林3种凋落物水平下土壤呼吸均不存在降雨激发效应,且凋落物添加与去除均显著降低水杉林土壤呼吸速率(P0.05)。麻栎林土壤呼吸与土壤湿度呈显著正相关关系(P0.05或P0.01)。水杉林添加凋落物条件下土壤呼吸速率与土壤温度呈显著正相关关系(P0.05)。该研究表明土壤呼吸对降雨脉冲的响应与森林类型、地表凋落物覆盖与否有密切关系,因此森林生态系统碳循环的变化除了考虑气候变化以外,还必须考虑林型和地表凋落物状况。
[Abstract]:Rainfall pulse has a transient stimulating effect on soil respiration. Surface litter is an important source of soil organic carbon and affects the process of rainfall infiltration and soil water content. Is the stimulative effect of rainfall on soil respiration affected by surface litter? The question is not yet clear. The effects of simulated rainfall events on soil respiration were studied in two forest types of Quercus acutissima forest and Metasequoia glyptostroboides forest in the transitional zone of subtropical and warm temperate zone in China under different litter input levels (control, litter addition and litter removal). In order to elucidate the response of soil respiration to rainfall pulse under different litter conditions. The results showed that for the secondary forest of Quercus acutissima, the soil respiration rate reached the peak at 10 min of rainfall, which were 4.72 渭 mol m ~ (-2) s ~ (-1) and 5.12 渭 mol m ~ (-2) s ~ (-1), respectively. There was no significant difference in soil respiration rate between litter removal and control treatment after rainfall event (P0.05). The litter layer has an important effect on the soil respiration rate of Quercus acutissima secondary forest after rainfall. Soil respiration of Metasequoia glyptostroboides forest was not stimulated by rainfall under three litter levels, and soil respiration rate of Metasequoia glyptostroboides forest was significantly decreased by adding and removing litter (P0.05). There was a significant positive correlation between soil respiration and soil moisture in Quercus acutissima forest (P0.05 or P0.01). There was a significant positive correlation between soil respiration rate and soil temperature in Metasequoia glyptostroboides forest with litter addition (P0.05). This study shows that the response of soil respiration to rainfall pulses is closely related to forest types, surface litter cover or not, so the changes of carbon cycle in forest ecosystems take into account not only climate change, but also climate change. Forest and surface litter conditions must also be considered.
【作者单位】：河南大学生命科学学院植物逆境重点实验室;黄河水利职业技术学院;
【基金】：国家自然科学基金(31200375) 国家博士后科学基金(2012M520066,2013T60699) 河南大学优秀青年培育基金(0000A40385)
【分类号】：S714

【相似文献】