Institute for Forest Resources & Environment of Guizhou, Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, College of Forestry, Guizhou University, Guiyang, China.
Institute for Forest Resources & Environment of Guizhou, Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou Province, College of Forestry, Guizhou University, Guiyang, China.
Sci Total Environ. 2024 Jan 10;907:167889. doi: 10.1016/j.scitotenv.2023.167889. Epub 2023 Oct 17.
Increased productivity generally promotes the accumulation of soil organic carbon (SOC) stocks. The productivity of mixed forests is mainly influenced by plant species richness (PSR), mixed forest age (MFA), and mixed species proportion (MSP). However, the influence of PSR, MFA, and MSP on SOC stocks along the soil profiles in Pinus massoniana mixed forests remains to be determined. We conducted a meta-analysis employing paired observations of SOC stocks from 1010 paired mixed and pure stands of P. massoniana from 110 publications. The findings revealed that SOC stocks were highly dependent on MFA and increased with increasing MFA in various soil layers, rather than the expected influence of PSR. MFA contributed 48.97 %, 83.20 %, and 38.41 % to the increased SOC stocks in the topsoil, midsoil, and subsoil, respectively. Furthermore, MSP also significantly affected the increase in SOC stock in the topsoil and midsoil when 40 % < MSP ≤ 60 %. Over the next 60 years, subsoil SOC accumulation will be limited by increased PSR and MSP in mixed forests. Mixing between P. massoniana and broadleaf tree species (especially Schima superba and Lespedeza bicolor) significantly enhanced SOC stocks along the soil profiles. SOC stocks along the soil profiles decreased with increasing dominant mixed tree species richness (e.g., broadleaf, deciduous broadleaf, arbuscular mycorrhizal, and the sum of conifer and broadleaf trees). Incorporating lower PSR (e.g., 2 ≤ N ≤ 10) and dominant mixed tree species richness (e.g., N = 2) practices may be optimization options for increasing SOC stocks. Overall, based on the expected goals, including optimizing productivity, enhancing carbon storage, mitigating climate change, and promoting biodiversity conservation, we emphasize the importance of incorporating MFA, MSP, tree species identity, and subsoil into forest management.
生产力的提高通常会促进土壤有机碳（SOC）储量的积累。混交林的生产力主要受植物物种丰富度（PSR）、混交林年龄（MFA）和混交物种比例（MSP）的影响。然而，PSR、MFA 和 MSP 对马尾松混交林土壤剖面中 SOC 储量的影响仍需确定。我们通过对 110 篇文献中 1010 对马尾松纯林和混交林 SOC 储量的配对观测进行了荟萃分析。结果表明，SOC 储量高度依赖于 MFA，并且随着各土层 MFA 的增加而增加，而不是 PSR 的预期影响。MFA 分别对表土、中土层和底土层中 SOC 储量的增加贡献了 48.97%、83.20%和 38.41%。此外，当 40%<MSP≤60%时，MSP 也显著影响表土和中土层 SOC 储量的增加。在未来 60 年，混交林增加的 PSR 和 MSP 将限制底土 SOC 的积累。马尾松与阔叶树种（特别是木荷和胡枝子）的混合显著增加了土壤剖面中的 SOC 储量。随着主要混交树种丰富度（如阔叶、落叶阔叶、丛枝菌根和针叶树与阔叶树的总和）的增加，土壤剖面中的 SOC 储量减少。较低的 PSR（如 2≤N≤10）和主要混交树种丰富度（如 N=2）的做法可能是增加 SOC 储量的优化选择。总的来说，基于优化生产力、增强碳储存、缓解气候变化和促进生物多样性保护等预期目标，我们强调了将 MFA、MSP、树种身份和底土纳入森林管理的重要性。
