地表凋落物对油松、沙棘人工林土壤呼吸的影响

发布时间：2018-11-21 10:30

【摘要】：通过对黄土丘陵区油松、沙棘人工林自然组(含凋落物)和去凋组(不含凋落物)土壤呼吸、5cm土壤温度和含水量的监测,研究地表凋落物对土壤呼吸的影响。在两种林分内分别设置20m×20m样地,样地内随机设置5个观测点,于2015年6月到2016年5月使用LI-8100系统进行监测。结果表明:(1)自然组油松林和沙棘林土壤呼吸季节动态及日动态均表现为单峰型变化曲线,沙棘土壤呼吸年均值[2.10μmol/(m~2·s)]显著高于油松[1.56μmol/(m~2·s),p0.05];去除凋落物后,两种林分土壤呼吸与自然组具有相似的季节及日动态特征,但土壤呼吸年均值不存在显著性差异。(2)沙棘林自然组土壤呼吸年均值显著高于去凋组[1.58μmol/(m~2·s),p0.05],凋落物呼吸对土壤总呼吸的贡献率为15.81%;油松林自然组与去凋组土壤呼吸年均值差异不显著,凋落物呼吸对土壤总呼吸的贡献率仅为1.61%。(3)自然组和去凋组中油松、沙棘林土壤呼吸与温度均存在显著指数关系(p0.05),与含水量则存在显著线性负相关关系(p0.05);两组处理土壤温度和含水量对土壤呼吸的单独解释量均较低(0.05%~37.82%),土壤呼吸主要受到温度和含水量共同作用的影响(8.01%~66.44%)。地表凋落物显著提高了沙棘林土壤呼吸的Q10和土壤呼吸量,但仅显著提高了油松林的Q10,对土壤呼吸量并未显著增加。油松林作为黄土丘陵区水土保持及生态恢复的造林树种更有利于该地区林地碳汇功能的提升。
[Abstract]:The effect of surface litter on soil respiration was studied by monitoring soil respiration, 5cm soil temperature and water content in natural group (including litter) and deregulation group (without litter) of Pinus tabulaeformis, Hippophae rhamnoides plantation in loess hilly region. 20m 脳 20m plots were set up in the two forest plots, and 5 observation points were randomly set up in the sample plots. LI-8100 system was used to monitor the plots from June 2015 to May 2016. The results showed that: (1) the seasonal and diurnal dynamics of soil respiration in natural group Pinus tabulaeformis and Hippophae rhamnoides forest showed a single peak variation curve. The annual mean of soil respiration of Hippophae rhamnoides [2.10 渭 mol/ (mt2 s)] was significantly higher than that of Pinus tabulaeformis [1.56 渭 mol/ (mt2 s), p0.05)]. After litter removal, soil respiration of the two stands had similar seasonal and daily dynamic characteristics as those of natural groups. But there was no significant difference in the annual mean of soil respiration. (2) the annual mean of soil respiration in the natural group of Hippophae rhamnoides forest was significantly higher than that in the control group [1.58 渭 mol/ (mt2 s), p0.05)], and the contribution rate of litter respiration to total soil respiration was 15.81%. There was no significant difference in annual mean of soil respiration between natural group and deregulation group in Pinus tabulaeformis forest. The contribution rate of litter respiration to soil total respiration was only 1.61%. (3) Pinus tabulaeformis var. tabulaeformis in natural group and unwithered group. There was a significant exponential relationship between soil respiration and temperature (p0.05) and a significant linear and negative correlation (p0.05) between soil respiration and water content in Hippophae rhamnoides forest. The single interpretation of soil temperature and water content to soil respiration in both groups was lower (0.05%, 37.82%), and soil respiration was mainly affected by the interaction of temperature and water content (8.01%, 66.44%). Surface litter significantly increased soil respiration Q10 and soil respiration in Hippophae rhamnoides forest, but only significantly increased Q10 in Pinus tabulaeformis forest, but did not significantly increase soil respiration. Pinus tabulaeformis forest as an afforestation tree species for soil and water conservation and ecological restoration in loess hilly region is more conducive to the enhancement of carbon sink function of forest land in this area.
【作者单位】：中国科学院教育部水土保持与生态环境研究中心;西北农林科技大学水土保持研究所;西北农林科技大学林学院;
【基金】：国家自然科学基金“黄土丘陵区油松和沙棘人工林的水分来源变化及其生理响应研究”(41501576) 公益性行业(国家气象局)科研专项(重大专项)“干旱气象科学研究—我国北方干旱致灾过程及机理”(GYHY2015060013)
【分类号】：S714

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