Variation in soil lignin protection mechanisms in five successional gradients of mixed broadleaf–pine forests. Issue 1 (19th February 2020)

• Record Type: Journal Article
• Authors: Feng, Yue; Han, Shijie; Chen, Wei; Gu, Yue; Stewart, Catherine E.; Zhang, Junhui; Geng, Shicong; Chen, Zhijie; Setälä, Heikki
• Is Part Of: Soil Science Society of America Journal. Volume 84:Issue 1(2020)
• Page Start: 232
• Page End: 250
• Publication Date: 2020-02-19
• Subjects: Soils -- United States -- Periodicals; Soil science -- Periodicals; Periodicals; 631.4973
• DOI: 10.1002/saj2.20032
• Languages: English
• ISSNs: 0361-5995

Abstract

Abstract: Over 200 yr of ecosystem succession in northeastern China, conifers have replaced broadleaf trees. Vegetation changes during forest succession may affect soil organic C (SOC) stability, which is associated with altered protection mechanisms. Lignin phenol composition, a predictor of soil organic matter variation, was assessed for macroaggregates, microaggregates, and silt–clay (SC) fractions from successional gradients in five forests aged 19 to 239 yr in the Changbai Mountains nature reserve. The large macroaggregates (4.00–8.00 and 2.00–4.00 mm) comprised 45.17 to 59.87% of bulk dry weight and 40.22 to 60.89% of SOC in the 19‐, 32‐, and 48‐yr‐old pioneer forests. However, we detected increased mass proportions and SOC contents in small macroaggregates (1.00–2.00 and 0.25–1.00 mm) in the mixed broadleaf–Korean pine ( Pinus koraiensis Siebold & Zucc.) forest after 122 yr. Lignin in bulk soil and aggregates in the 122‐yr‐old stand had lower acid/aldehyde ratios for the vanillyl and syringyl types than other stands, indicating less lignin decomposition. The highest C (198.20 g kg −1 soil) and lignin concentrations (6.14 mg 100 mg −1 C) were detected in the bulk soil from the 239‐yr‐old stand, where SC fraction occupied 56.18% of the C and 84.17% of the lignin content in bulk soil. Forest succession from broadleaf to a broadleaf–pine mixture shifted SOC sequestration and lignin protection from aggregates to SC fractions, along with the development of plant litter composition, fine‐root biomass and turnover, and microorganism biomass, which prompted effective long‐term SOC accumulation in successional forest communities.