喀斯特不同植被恢复阶段土壤有机酸季节变化与有效氮磷的关系

生态学杂志

喀斯特不同植被恢复阶段土壤有机酸季节变化与有效氮磷的关系

潘复静¹,张伟^2,4,梁月明³,王克林^2,4*,靳振江¹

(¹桂林理工大学环境科学与工程学院、广西环境污染控制理论与技术重点实验室，广西桂林 541000；^2中国科学院亚热带农业生态研究所，亚热带农业生态过程重点实验室，长沙 410125；³中国地质科学院岩溶地质研究所，自然资源部、广西壮族自治区岩溶动力学重点实验室，广西桂林 541000； ⁴中国科学院环江喀斯特生态系统观测研究站，广西环江 547100)

出版日期:2020-04-10 发布日期:2020-04-10

Seasonal changes of soil organic acid concentrations in relation to available N and P at different stages of vegetation restoration in a karst ecosystem.

PAN Fu-jing¹, ZHANG Wei^2,4, LIANG Yue-ming³, WANG Ke-lin^2,4*, JIN Zhen-jiang¹

(¹ Guangxi Key Laboratory of Theory and Technology for Environmental Pollution Control, College of Environmental and Engineering, Guilin University of Technology, Guilin 541000, Guangxi, China; ² Key Laboratory for Agroecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China; ³ Key Laboratory of Karst Dynamics, Ministry of Natural Resources & Guangxi Zhuangzu Autonomy Region, Institute of Karst Geology, Chinese Academy of Geological Sciences, Guilin 541000, Guangxi, China; ⁴ Huanjiang Observation and Research Station for Karst Ecosystems, Huanjiang 547100, Guangxi, China).

Online:2020-04-10 Published:2020-04-10

摘要/Abstract

摘要： 植物分泌有机酸在提高土壤养分有效性方面起到重要作用。为了解喀斯特地区不同植被恢复阶段土壤有机酸含量季节性变化与氮磷有效性的关系，在灌木林和原生林各选择3种优势植物，测定雨季和旱季两个季节根际土和非根际土的有机酸含量、碳氮磷含量和比值、有效性氮磷含量及微生物生物量碳。结果表明：原生林植物根际土的草酸含量高于灌木林，而苹果酸和乙酸含量则低于灌木林；根际土草酸含量均高于非根际土；2个植被根际土和非根际土的草酸含量在雨季高于旱季，而苹果酸和乙酸含量则低于旱季；土壤草酸含量与有机碳、全氮、全磷和N∶P值呈显著正相关，与C∶N呈显著负相关；土壤有效氮和有效磷与草酸和微生物生物量碳呈显著正相关。上述结果表明，植物分泌有机酸的季节性变化与土壤养分状态和自身养分需求相关，而有机酸耦合微生物对养分有效性的提高具有积极的作用。因此，根际土的有机酸季节变化可能是喀斯特生态系统中植物适应土壤养分限制的一种重要机制。

Abstract:

Soil organic acids released by plants are important for improving soil nutrient availability. To clarify the relationships between soil organic acids and the concentrations and ratios of nutrients at different stages of vegetation restoration in a karst ecosystem, we measured the concentrations of oxalic acid, malic acid, acetic acid, organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), nitrogen (AN) and phosphorus availability (AP), and microbial biomass carbon (MBC) in rhizosphere soils and bulk soils of six plant species (three for shrubland and three for primary forest) in dry and wet seasons. Our results showed that the oxalic acid concentrations of rhizosphere soils in primary forest were higher than those in shrubland in both seasons, whereas the concentrations of malic acid and acetic acid showed an opposite trend. Moreover, the concentrations of oxalic acid in rhizosphere soils in both vegetations were higher than those of bulk soils in both seasons. The concentrations of oxalic acid of rhizosphere and bulk soils were higher in the wet season than that in the dry season, whereas those of malic acid and acetic acid were lower. Furthermore, the oxalic acid concentrations were significantly positively correlated with SOC, TN, TP, AN, and N∶P ratios, and significantly negatively correlated with C∶N ratios. Soil AN and AP concentrations were significantly positively correlated with oxalic acid concentrations and MBC. Our results suggest that seasonal changes in organic acid exudate may be related to soil nutrient status and plant nutrition requirements, and that the interactions between organic acids and soil microorganisms may enhance nitrogen and phosphorus availability. Therefore, seasonal changes in organic acid concentrations of rhizosphere soils may be an important mechanism for plant adaption to soil nutrient limitations in karst ecosystems.

潘复静,张伟,梁月明,王克林,靳振江. 喀斯特不同植被恢复阶段土壤有机酸季节变化与有效氮磷的关系[J]. 生态学杂志.

PAN Fu-jing, ZHANG Wei, LIANG Yue-ming, WANG Ke-lin, JIN Zhen-jiang. Seasonal changes of soil organic acid concentrations in relation to available N and P at different stages of vegetation restoration in a karst ecosystem.[J]. cje.