冻融作用对金川泥炭沼泽土壤酶活性的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 冻融作用对金川泥炭沼泽土壤酶活性的影响 DOI: 10.5846/stxb202107091856 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 中央高校基本科研业务费(2412019FZ001);吉林省自然科学基金项目(20210101397JC);国家自然科学基金项目(32071599) Effects of freezing and thawing on soil enzyme activities in Jinchuan peatlands Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为研究冻融作用对泥炭沼泽土壤酶活性的影响,选取金川草本泥炭沼泽为研究对象,采集表层(0-15 cm)和深层(15-30 cm)土壤样品,进行室内冻融模拟实验。实验设置(-5-5℃)和(-10-10℃)两个冻融幅度,分析经0、1、3、5、7、15次冻融循环处理后土壤3种水解酶活性(β-1,4-葡萄糖苷酶(BG)、β-1,4-N-乙酰葡糖胺糖苷酶(NAG)和酸性磷酸酶(AP))和2种氧化酶(过氧化物酶(PER)和多酚氧化酶(PPO))的变化特征,并结合土壤有机碳、氮组分,探讨泥炭沼泽土壤酶活性与土壤活性有机碳、氮组分间的相关关系。结果表明,冻融频次与冻融幅度均显著影响了土壤有机碳、氮组分及土壤酶活性。-10-10℃冻融作用下,土壤可溶性有机碳(DOC)与可溶性有机氮(DON)含量呈现先增加后降低的变化趋势。-5-5℃的冻融作用下土壤DOC与DON释放相对-10-10℃冻融作用更为缓慢,在冻融结束后呈现增加趋势。冻融循环增加了土壤微生物碳(MBC)含量,而降低了土壤微生物氮(MBN)含量。冻融幅度对土壤MBC和MBN的影响表现为-5-5℃ ＜ -10-10℃。随着土层的增加,土壤MBC、MBN和DOC含量的幅度变化表现为0-15 cm ＜ 15-30 cm,而土壤DON含量幅度变化表现为0-15 cm ＞ 15-30 cm。冻融循环降低了土壤水解酶活性和氧化酶活性。冻融幅度对土壤水解酶活性的影响表现为-5-5℃ > -10-10℃,对土壤氧化酶活性的影响表现为-5-5℃ < -10-10℃。随着土层深度的增加,土壤水解酶活性变化的幅度表现为0-15 cm ＜ 15-30 cm,土壤氧化酶活性变化的幅度表现为0-15 cm ＞ 15-30 cm。土壤酶活性与土壤MBC和MBN含量呈正相关,而与土壤DOC含量呈显著负相关(P ＜ 0.05)。研究结果表明冻融作用初期促使部分微生物死亡,其死亡残体释放的可利用养分,促进了适应冻融作用的微生物生长,但在培养后期随着土壤养分的消耗,土壤微生物量呈现下降趋势,进而最终降低了土壤酶活性。 Abstract:The aim of this study was to analyze the influence of freezing-thawing cycles on soil enzyme activity in peatland. A laboratory freezing-thawing simulation test was carried out using soil samples from surface layer (0-15 cm) and deep layer (15-30 cm) in Jinchuan herbaceous peatland. Two freezing-thawing cycles amplitudes, namely, (-5-5℃) and (-10-10℃), were tested. Soil samples were then processed during the 1st, 3rd, 5th, 7th and 15th freezing-thawing cycles. We analyzed the activities of three hydrolases (β-1, 4-glucosidase (BG), 4-N-acetylglucosaminosidase (NAG) and acid phosphatase (AP)), two oxidases (peroxidase (PER) and polyphenol oxidase (PPO)), dissolved organic carbon and nitrogen (DOC and DON), and microbial biomass carbon and nitrogen (MBC and MBN) which were compared to the values of the initial freezing-thawing cycle. We also analyzed the relationship between the soil organic carbon and nitrogen concentrations and soil enzyme activities in peatland. The results demonstrated that freezing-thawing cycles frequency and freezing-thawing amplitudes had significant effects on soil organic carbon and nitrogen fractions and soil enzyme activities. Soil DOC and DON concentrations increased first and then decreased under -10-10℃ freezing-thawing cycling. The release of soil DOC and DON concentrations under -5-5℃ freezing-thawing cycling was slower than those under -10-10℃ freezing-thawing cycling, which showed an increasing trend at the end of freezing and thawing. Soil MBC concentrations increased but MBN concentrations decreased after freezing-thawing cycles. The effects of freezing-thawing amplitude on MBC and MBN concentrations under the amplitude of -10-10℃ were greater than those of -5-5℃. The effects of freezing-thawing cycles on MBC, MBN, and DOC concentrations gradually increased with the increases in soil depth, but the opposite phenomenon was observed with respect to the effects of freezing-thawing cycles on DON concentration. Freezing-thawing cycles had a negative influence on the soil enzyme activities. The effects of freezing-thawing cycles on the hydrolase activities under the amplitude of -5-5℃ were greater than those of the amplitude of -10-10℃, whereas oxidase activities showed an opposite pattern. The effects of freezing-thawing cycles on hydrolase activities gradually increased with soil depth increasing, but the opposite phenomenon was observed with respect to the effects of freezing-thawing cycles on oxidase activities. Soil enzyme activities were positively correlated with MBC and MBN concentration, but negatively correlated with DOC concentration (P<0.05). The results indicated that, at the early stage of freezing-thawing cycling, the available nutrients released by the dead residues of some dead microorganisms promoted the growth of microorganisms to adapt to freezing-thawing. However, with the consumption of soil nutrients at the later stage of freezing-thawing cycling, soil microbial biomass showed a downward trend, which ultimately reduced soil enzyme activities. 参考文献 相似文献 引证文献