川西亚高山针叶林土壤有机层酶活性

发布时间：2019-03-09 18:36

【摘要】：凋落物分解在维持亚高山森林的"自肥"机制及生态系统结构和功能具有不可替代的作用。以川西亚高山森林的岷江冷杉(Abies faxoniana)和粗枝云杉(Picea aspoerata)针叶林土壤有机层的新鲜凋落物层(LL)、半分解层(FL)和腐殖质层(HL)凋落叶以及矿质土壤层土壤为对象,分别模拟凋落叶的不同分解阶段,研究凋落叶不同分解阶段与碳、氮、磷转化相关的酶活性特征。结果表明,两个树种土壤有机层凋落叶有机碳和纤维素含量以及C∶N以LL最高,木质素含量以FL最高。β-1,4-外切葡聚糖酶、β-葡聚糖苷酶和酸性磷酸酶活性随凋落叶分解程度的加深而降低,而多酚氧化酶活性则相反;过氧化物酶活性随凋落叶分解程度加深在云杉林呈降低趋势,在冷杉林则呈升高趋势。云杉林凋落叶的亮氨酸氨基肽酶、N-乙酰-β-D-氨基葡萄糖苷酶活性随分解程度加深而先升高后降低,冷杉林的N-乙酰-β-D-氨基葡萄糖苷酶活性随分解程度加深呈下降趋势。凋落叶层次和树种及其交互作用显著影响β-葡聚糖苷酶、过氧化物酶活性、多酚氧化酶、N-乙酰-β-D-氨基葡萄糖苷酶和酸性磷酸酶活性,树种对β-1,4-外切葡聚糖酶和亮氨酸氨基肽酶活性影响不显著。β-1,4-外切葡聚糖酶、β-葡聚糖苷酶、过氧化物酶和酸性磷酸酶活性与木质素?N比值呈极显著负相关,亮氨酸氨基肽酶和N-乙酰-β-D-氨基葡萄糖苷酶活性与碳含量呈极显著正相关。以上结果表明基质质量变化是影响川西亚高山森林针叶林凋落叶分解过程中酶活性变化的驱动力。
[Abstract]:Litter decomposition plays an irreplaceable role in maintaining the "self-fertilization" mechanism and ecosystem structure and function of subalpine forests. The fresh litter layer (LL),) of soil organic layer of Minjiang fir (Abies faxoniana) and spruce (Picea aspoerata) coniferous forest in Western Sichuan was studied. The semi-decomposing layer (FL) and humus layer (HL) litter and mineral soil layer soil were studied. The characteristics of enzyme activity related to the transformation of carbon, nitrogen and phosphorus in different decomposition stages of litter were studied by simulating the different decomposition stages of litter. The results showed that the content of organic carbon and cellulose in the soil organic layer of two tree species and the content of C _ (N) in litter were the highest in LL and the highest in lignin content, 尾-1,4-glucanase, and 尾-1,4-glucanase were the highest in soil organic layer. The activity of 尾-glucosidase and acid phosphatase decreased with the increase of litter decomposition, but the activity of polyphenol oxidase was opposite. The activity of peroxidase decreased in spruce forest with the deepening of litter decomposition, but increased in fir forest. The activities of leucine aminopeptidase and N-acetyl-尾-D-glucosaminidase in the litter of Picea spruce forest increased first and then decreased with the increase of decomposition degree. The activity of N-acetyl-尾-D-glucosaminidase in fir forest decreased with the increase of decomposition degree. The activities of 尾-glucosidase, peroxidase, polyphenol oxidase, N-acetyl-尾-D-glucosaminidase and acid phosphatase were significantly affected by litter level and tree species interaction. The effects of tree species on 尾-1, 4-exoglucanase and leucine aminopeptidase activities were not significant, and the activities of 尾-1, 4-exoglucanase, 尾-glucosidase, peroxidase and acid phosphatase were negatively correlated with the ratio of lignin to N, and there was no significant correlation between the activities of 尾-1, 4-exoglucanase and leucine aminopeptidase. The activities of leucine aminopeptidase and N-acetyl-尾-D-glucosaminidase were positively correlated with carbon content. The above results indicate that the change of substrate quality is the driving force of enzyme activity change during litter decomposition of coniferous forest in the alpine forests of West Sichuan.
【作者单位】：四川农业大学生态林业研究所//长江上游林业生态工程四川省重点实验室//高山森林生态系统定位研究站//水土保持与荒漠化防治省级重点实验室;长江上游生态安全协同创新中心;
【基金】：国家自然科学基金项目(31500509;31570445;31500358;31670526;31622018) 高等学校博士学科点专项科研基金项目(20135103110002) 四川省教育厅青年项目(14ZB0001) 四川农业大学科研兴趣培养项目(ky2016204);四川农业大学大学生创新训练计划项目(1510626065)
【分类号】：S714.2

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