College of Horticulture and Forestry Sciences / Hubei Engineering Technology Research Center for Forestry Information, Huazhong Agricultural University, Wuhan 430070, China.
Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
Sci Total Environ. 2021 May 1;767:144322. doi: 10.1016/j.scitotenv.2020.144322. Epub 2020 Dec 25.
The spatial heterogeneity of light and nutrient deficiency occurs in many forest understories. Proper fertilization management of unhealthy forests can benefit forest understory diversity and improve the stability of degraded soil; and clonal integration is a major advantage of resource sharing for many forest understory vegetation, such as pteridophytes. In this study, we tested whether understory soil fertilization and clonal integration under light heterogeneity were able to increase the performance and diversity of understory vegetation and soil microbial communities in nature. Field experiments-with or without phosphorus (P) addition, with intact or severed rhizome, and under homogeneous or heterogeneous light environments-were conducted in the understory of a typical evergreen forest in southeast China. Light heterogeneity, P addition and clonal integration promoted the growth, diversity and evenness of ferns and soil microbial biomass C, N and P (MBC, MBN and MBP) at both experimental plot and patch level. They also increased Chao1 richness and Shannon diversity of soil fungal communities at patch level, especially in the high light patches with P addition. The positive effects of P addition and clonal integration on the growth and diversity of ferns and soil microbial biomass were greatly increased under heterogeneous light. The positive effects of clonal integration on the growth were the greatest in the heterogeneous high light patches. Moreover, the interactive effect of P addition and clonal integration increased soil MBN and MBP. Clonal integration promoted the increased growth and diversity of ferns and soil MBC in the heterogeneous light environment (9.35%-35.19%), and enhanced soil MBN and MBP in the P addition treatment (9.03%-12.96%). The interactive effect of P addition and clonal integration largely led to the transition of fungal groups from slow-growing oligotrophic types to fast-growing copiotrophic types. Our results show that the interactions between clonal integration and/or P addition under light heterogeneity increase the benefits of ferns in light-rich patches, and further promote integrative performance of ferns and soil microbial communities.
光和养分缺乏的空间异质性在许多森林林下发生。对不健康森林进行适当的施肥管理可以有益于林下多样性，并提高退化土壤的稳定性；克隆整合是许多森林林下植被（如蕨类植物）资源共享的主要优势。在这项研究中，我们测试了林下土壤施肥和光异质性下的克隆整合是否能够提高自然条件下林下植被和土壤微生物群落的性能和多样性。在东南中国典型常绿森林的林下进行了野外实验——有无磷（P）添加、完整或切断根茎、均匀或不均匀光环境。光异质性、P 添加和克隆整合促进了蕨类植物和土壤微生物生物量 C、N 和 P（MBC、MBN 和 MBP）在实验斑块和斑块水平上的生长、多样性和均匀性。它们还增加了土壤真菌群落的 Chao1 丰富度和 Shannon 多样性，特别是在有 P 添加的高光斑块中。在异质光下，P 添加和克隆整合对蕨类植物和土壤微生物生物量的生长和多样性的积极影响大大增加。在异质高光斑块中，克隆整合对生长的积极影响最大。此外，P 添加和克隆整合的相互作用增加了土壤 MBN 和 MBP。克隆整合促进了异质光环境下蕨类植物和土壤 MBC 的生长和多样性的增加（9.35%-35.19%），并增强了 P 添加处理下的土壤 MBN 和 MBP（9.03%-12.96%）。P 添加和克隆整合的相互作用在很大程度上导致了真菌群从生长缓慢的寡养型向生长迅速的富养型的转变。我们的结果表明，光异质性下克隆整合和/或 P 添加的相互作用增加了富光斑块中蕨类植物的收益，并进一步促进了蕨类植物和土壤微生物群落的综合性能。
