Hu Xuan, Shu Qi, Guo Wen, Shang Zean, Qi Lianghua
Key Laboratory of National Forestry and Grassland Administration/Beijing for Bamboo & Rattan Science and Technology, International Centre for Bamboo and Rattan, Beijing 100102, China.
National Positioning and Monitoring Station for Ecosystem of Bamboo and Rattan, Sanya 572000, China.
Plants (Basel). 2022 May 19;11(10):1344. doi: 10.3390/plants11101344.
The characteristics of plant and soil bacterial communities in forest ecosystems have been reported, but our understanding of the relationship between plant communities and soil bacteria in different stages of secondary tropical rainforest succession is still poor. In June 2018, three different natural successional stages of tropical lowland rainforests, early (33 years), early-mid (60 years), and mid successional stage (73 years), in Hainan Island, China, were selected for this study. By conducting field investigation and 16S rRNA gene high-throughput sequencing, the composition and diversity of tree communities, the niche overlap of tree species with legumes among tree species, and the diversity and composition of soil bacterial communities and co-occurrence networks within communities across the successional stages were investigated. The results showed that plant richness and species diversity increased significantly during the secondary succession of tropical lowland rainforests. The order of positive correlations between nitrogen-fixing legumes and other species in plant communities was early-mid > mid > early successional stage. Soil nutrient content and soil bacterial richness were highest in the early-mid stages of succession, followed by mid and early stages of succession. Organic matter (OM), total nitrogen (TN), alkali nitrogen (AN), and available phosphorus (AP) had a stronger positive impact on soil bacterial communities. Co-occurrence network analysis showed that with the advancement of rainforests succession, the negative correlation between soil bacterial species decreased, and the community stability increased. Overall, as a result of tropical lowland rainforest secondary natural succession, the richness and diversity of plant communities increased, which altered the living conditions of nitrogen-fixing legumes and the soil properties, and the network complexity of soil bacterial communities increased with the rising of rainforest soil nutrient content.
森林生态系统中植物和土壤细菌群落的特征已有报道，但我们对热带次生雨林演替不同阶段植物群落与土壤细菌之间关系的了解仍然不足。2018年6月，本研究选取了中国海南岛热带低地雨林的三个不同自然演替阶段，即早期（33年）、中早期（60年）和中期演替阶段（73年）。通过实地调查和16S rRNA基因高通量测序，研究了不同演替阶段树木群落的组成和多样性、树种与豆科植物的生态位重叠、土壤细菌群落的多样性和组成以及群落内的共现网络。结果表明，热带低地雨林次生演替过程中植物丰富度和物种多样性显著增加。植物群落中固氮豆科植物与其他物种之间正相关的顺序为中早期>中期>早期演替阶段。土壤养分含量和土壤细菌丰富度在演替的中早期最高，其次是中期和早期。有机质（OM）、总氮（TN）、碱解氮（AN）和有效磷（AP）对土壤细菌群落有更强的正向影响。共现网络分析表明，随着雨林演替的推进，土壤细菌物种之间的负相关性降低，群落稳定性增加。总体而言，由于热带低地雨林的次生自然演替，植物群落的丰富度和多样性增加，这改变了固氮豆科植物的生存条件和土壤性质，土壤细菌群落的网络复杂性随着雨林土壤养分含量的升高而增加。
