College of Life Science and Technology, National Engineering Laboratory for Applied Technology in Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China; Lutou National Station for Scientific Observation and Research of Forest Ecosystems in Hunan Province, China; Technology Innovation Center for Ecological Protection and Restoration in Dongting Lake Basin, MNR, China.
College of Life Science and Technology, National Engineering Laboratory for Applied Technology in Forestry & Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, China; Lutou National Station for Scientific Observation and Research of Forest Ecosystems in Hunan Province, China; Technology Innovation Center for Ecological Protection and Restoration in Dongting Lake Basin, MNR, China.
Sci Total Environ. 2024 Jan 20;909:168349. doi: 10.1016/j.scitotenv.2023.168349. Epub 2023 Nov 12.
Forest ecosystem productivity and function is strongly influenced by the interaction between soil organisms and their resource use that can be impeded by an imbalance of ecological stoichiometry. Soil microorganisms are known to have an important role in biogeochemical cycling which is strongly influenced by ecological stoichiometry. However, there is limited understanding of how soil micro-food web respond to stoichiometric imbalances during forest restoration. Here, we investigated the effect of forest restoration on soil physio-chemical properties and the structure and function of soil micro-food web along a chronosequence of transformation stages: (i) early stage monoculture plantation of Chinese fir (Cunninghamia lanceolata) comprised of three age classes (5, 10 and 20 years); (ii) mid-stage conifer-broadleaved mixed forest; and (iii) late-stage mixed species broadleaved forest in south China. Results showed that forest restoration from C. lanceolata monocultures to mixed species broadleaved forest significantly increased soil organic carbon and total nitrogen. Soil bacteria, fungi, protists and nematodes abundance increased and the co-occurrence networks of soil biota became more complex and stable along the restoration chronosequence. In contrast, soil nitrogen and phosphorus limitations, particularly phosphorus limitation, increased along the chronosequence. In addition, soil exoenzyme activity suggested that the microbial investment in resource acquisition shifted from C- to nutrient-acquiring enzymes from the earlier to the later restoration stages. Availability of soil resources (e.g., dissolved organic carbon, ammonium, and available phosphate) appeared to have an important role in regulating soil food web composition, structure and stability during forest restoration. We conclude that nutrient limitation, particularly phosphorus limitation, likely has an important role in determining the stability of soil food webs during forest restoration. These findings contribute to our understanding of the relationships between soil nutrient limitation and soil micro-food web, and have implications for carbon sequestration through forest restoration and management in southern China.
森林生态系统生产力和功能受到土壤生物与其资源利用之间相互作用的强烈影响，而这种相互作用可能会受到生态化学计量平衡的阻碍。土壤微生物在生物地球化学循环中起着重要作用，而生态化学计量对生物地球化学循环有很强的影响。然而，对于森林恢复过程中土壤微食物网对化学计量失衡的响应，人们的了解有限。在这里，我们研究了森林恢复对土壤理化性质以及土壤微食物网结构和功能的影响，研究对象沿着转化阶段的时间序列：（i）由三个年龄组（5、10 和 20 年）组成的早期杉木（Cunninghamia lanceolata）单一栽培人工林；（ii）中期针叶树-阔叶树混交林；（iii）华南晚期混交阔叶树种人工林。结果表明，从杉木单一栽培向混交阔叶树种人工林的森林恢复显著增加了土壤有机碳和总氮。土壤细菌、真菌、原生动物和线虫的丰度增加，土壤生物群落的共生网络沿着恢复时间序列变得更加复杂和稳定。相比之下，土壤氮素和磷素限制，特别是磷素限制，沿着时间序列增加。此外，土壤外切酶活性表明，从早期到后期恢复阶段，微生物在资源获取方面的投资从 C 酶转向养分获取酶。土壤资源的可用性（例如，溶解有机碳、铵和有效磷）似乎在调节森林恢复过程中土壤食物网的组成、结构和稳定性方面起着重要作用。我们得出结论，养分限制，特别是磷素限制，可能在决定森林恢复过程中土壤食物网的稳定性方面起着重要作用。这些发现有助于我们理解土壤养分限制与土壤微食物网之间的关系，并对中国南方通过森林恢复和管理进行碳固存具有重要意义。
