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应用生态学报 ›› 2022, Vol. 33 ›› Issue (4): 939-948.doi: 10.13287/j.1001-9332.202204.001

• 研究论文 • 上一篇    下一篇

不同林龄杉木人工林土壤团聚体磷素分布特征

张喆, 黄永珍, 张超, 叶绍明, 王晟强*   

  1. 广西大学林学院, 南宁 530004
  • 收稿日期:2021-05-19 接受日期:2022-01-26 出版日期:2022-04-15 发布日期:2022-10-15
  • 通讯作者: * E-mail: shengqiang@gxu.edu.cn
  • 作者简介:张 喆, 女, 1994年生, 硕士研究生。主要从事土壤生态研究。E-mail: zhangzhe94@foxmail.com
  • 基金资助:
    广西创新驱动发展专项(桂科AA17204087-8)和国家级大学生创新训练项目(202110593049)资助。

Distribution of phosphorus fractions in soil aggregates in Chinese fir plantations with different stand ages

ZHANG Zhe, HUANG Yong-zhen, ZHANG Chao, YE Shao-ming, WANG Sheng-qiang*   

  1. Forestry College of Guangxi University, Nanning 530004, China
  • Received:2021-05-19 Accepted:2022-01-26 Online:2022-04-15 Published:2022-10-15

摘要: 探究不同林龄杉木人工林土壤团聚体各形态磷素的分布特征有利于提升杉木人工林土壤磷素有效性。本研究选取位于广西融水县的幼龄(9 a)、中龄(17 a)、成熟(26 a)杉木人工林和邻近撂荒地(CK),利用干筛法将采集到的表层(0~20 cm)原状土壤分为4个粒级团聚体(>2、1~2、0.25~1和<0.25 mm),测定各粒级团聚体中不同形态磷组分。结果表明: 1)不同林龄杉木人工林土壤团聚体组成差异显著,CK和各林龄杉木人工林中>2 mm粒级团聚体含量显著较高,随林龄的增长先增后减,在17 a时最高;土壤平均重量直径(MWD)和几何平均直径(GMD)的变化趋势与>2 mm粒级团聚体一致。2)CK和各林龄杉木人工林中各粒级土壤团聚体全磷、无机磷和有机磷含量差异均不显著,而土壤有效磷含量在>2 mm粒级团聚体中显著较高,达1.23~7.33 mg·kg-1;不同林龄杉木人工林土壤团聚体及全土全磷、有效磷和无机磷含量均显著高于CK,并随杉木林龄的增长先增后减,全土总磷和有效磷含量在9 a时最高,分别为322.40和7.33 mg·kg-1,全土无机磷含量在17 a时最高,为114.05 mg·kg-1;全土有机磷含量随杉木林龄的增长先增再减再增,在9 a时最高,为210.00 mg·kg-1。3)不同粒级土壤团聚体磷储量与土壤团聚体组成比例显著相关。CK和各林龄杉木人工林中>2 mm粒级团聚体各形态磷储量较高。除有机磷外,各形态土壤磷储量均随杉木林龄的增长先增后减。综上,林龄17 a之前,杉木人工林的种植有利于提升土壤团聚体稳定性,促进土壤磷素水平的提升;林龄17 a后,>2 mm粒级团聚体的破碎导致土壤团聚体稳定性和土壤磷素供应水平逐渐下降。因此,在杉木人工林培育栽种17 a以后应重视土壤中>2 mm粒级团聚体的保护,以保障土壤质量,维持土壤供磷水平。

关键词: 杉木林, 土壤团聚体, 无机磷, 有机磷

Abstract: Exploring the distribution of phosphorus (P) fractionsin soil aggregates is helpful to improve soil P availa-bility during Chinese fir planting. In this study, soil samples were collected in the 0-20 cm soil layer from Chinese fir plantations with different stand ages (9 a, 17 a, and 26 a) and one nearby abandoned land (CK) in Rongshui County, Guangxi, China. Soil aggregates were classified into >2 mm, 1-2 mm, 0.25-1 mm, and <0.25 mm size classes through dry-sieving process, and then soil P fractions in different sized aggregates were measured. These results showed that: 1) The composition of soil aggregates showed significant difference among different stand ages. As the major aggregate fractions in soil, the contents of >2 mm aggregates increased firstly and then decreased over time, and peaked in the 17 a Chinese fir plantation. The changes of soil mean weight diameter (MWD) and geometric mean diameter (GMD) during Chinese fir planting were the same as the content of >2 mm aggregates. 2) Soil total P, inorganic P, and organic P contents did not differ among different sized aggregates. However, soil available P content was mainly distributed in >2 mm aggregates with a range of 1.23-7.33 mg·kg-1. Compared with CK, soil total P, available P, and inorganic P contents were significantly higher in Chinese fir plantations, and their contents increased firstly and then decreased over time. Soil total P (322.40 mg·kg-1) and available P (7.33 mg·kg-1) contents were the highest in the 9 a plantations, and soil inorganic P content (114.05 mg·kg-1) was the highest in the 17 a plantation. Moreover, soil organic P content showed an order of 9 a > 26 a >17 a > CK, with the highest content (210.00 mg·kg-1) in the 9 a plantation. 3) The distribution of P stock in soil aggregates was related to the contents of different sized aggregates, with >2 mm aggregates having the highest P stock. Except for organic P, soil P stock increased firstly and then decreased with the increases of stand age. In conclusion, Chinese fir planting was helpful to improve soil aggregate stability and to promote the increase of soil P level before the stand age of 17 a. However, Chinese fir planting could result in the degradation of soil aggregates and in the decrease of soil P level after 17 a. The formation and stabilization of >2 mm aggregates played an important role in the maintenance of soil quality and soil P supply level after 17 a Chinese fir planting.

Key words: Chinese fir plantation, soil aggregate, inorganic phosphorus, organic phosphorus