Soil Abiotic Properties and Plant Functional Traits Mediate Associations Between Soil Microbial and Plant Communities During a Secondary Forest Succession on the Loess Plateau

Abstract

In the context of secondary forest succession, aboveground-belowground interactions are known to affect the dynamics and functional structure of plant communities. However, the links between soil microbial communities, soil abiotic properties, plant functional traits in the case of semi-arid and arid ecosystems, are unclear. In this study, we investigated the changes in soil microbial species diversity and community composition, and the corresponding effects of soil abiotic properties and plant functional traits, during a ≥150-year secondary forest succession on the Loess Plateau, which represents a typical semi-arid ecosystem in China. Plant community fragments were assigned to six successional stages: 1–4, 4–8, 8–15, 15–50, 50–100, and 100–150 years after abandonment. Bacterial and fungal communities were analyzed by high-throughput sequencing of the V4 hypervariable region of the 16S rRNA gene and the internal transcribed spacer (ITS2) region of the rRNA operon, respectively. A multivariate variation-partitioning approach was used to estimate the contributions of soil properties and plant traits to the observed microbial community composition. We found considerable differences in bacterial and fungal community compositions between the early (S1–S3) and later (S4–S6) successional stages. In total, 18 and 12 unique families were, respectively, obtained for bacteria and fungi, as indicators of microbial community succession across the six stages. Bacterial alpha diversity was positively correlated with plant species alpha diversity, while fungal diversity was negatively correlated with plant species diversity. Certain fungal and bacterial taxa appeared to be associated with the occurrence of dominant plant species at different successional stages. Soil properties (pH, total N, total C, NH 4 -N, NO 3 -N, and PO 4 -P concentrations) and plant traits explained 63.80% and 56.68% of total variance in bacterial and fungal community compositions, respectively. These results indicate that soil microbial communities are coupled with plant communities via the mediation of microbial species diversity and community composition over a long-term secondary forest succession in the semi-arid ecosystem. The bacterial and fungal communities show distinct patterns in response to plant community succession, according to both soil abiotic properties and plant functional traits.

Legacy Effects Overshadow Tree Diversity Effects on Soil Fungal Communities in Oil Palm-Enrichment Plantations

“…In agreement to our results, long-lasting land-use effects on the soil fungal community composition were demonstrated even after 80 years of natural succession from farming and logging in tropical forests of Puerto Rico [68]. Furthermore, Chai et al [77] demonstrated that significant compositional differences of the fungal community between managed and recovering sites were only apparent after more than a decade of natural succession from farmland to secondary forest. No differences were found in early establishment phases up to 15 years after stopping management [77].…”

“…Furthermore, Chai et al [77] demonstrated that significant compositional differences of the fungal community between managed and recovering sites were only apparent after more than a decade of natural succession from farmland to secondary forest. No differences were found in early establishment phases up to 15 years after stopping management [77]. Agroforestry systems promote compositional shifts in the fungal community and abundance of mycorrhizal fungi compared to monocultures for a variety of tropical crops, including coffee [78], cacao [35], and rubber [28].…”

The role of intraspecific trait variability and soil properties in community assembly during forest secondary succession

“…The distance between any two plots at the same stage was more than 1 km to include different community types and avoid spatial autocorrelation in variables and pseudo-replications (Conti and D ıaz 2013). The plot size was 20 9 20 m. Specifically, our previous survey and study (Chai et al 2019). S1-S6 represent 1-4, 4-8, 8-15, 15-50, 50-100, and 100-150 yr after abandonment, respectively. ensured that all the plots had the same agricultural history and are now on a similar trajectory toward climax forest under natural conditions (Chai et al 2015).…”

Soil Property and Plant Diversity Determine Bacterial Turnover and Network Interactions in a Typical Arid Inland River Basin, Northwest China

“…Distribution patterns and drivers of soil microbes have attracted extensive attention over the past several years. Previous studies have provided evidences that environmental heterogeneity could drive the composition and distribution of the microbial community (Maestre et al, 2015; Chai et al, 2019; Vieira et al, 2019; Zhang L. et al, 2019). For instance, Zhang K. et al (2019) confirmed that differences in salinity negatively correlated with the similarity of the microbial community in a desert ecosystem, and the composition of the bacterial community converged on salt-tolerant species with increasing habitat salinity (Rath et al, 2019).…”

“…In addition, some studies have indicated that soil water content (WC; Zhang et al, 2013; Maestre et al, 2015) and soil texture (Hu et al, 2014) have also affected a shift in the microbial community composition. Plant attributes, including plant diversity and functional traits, may be another factor that regulates microbes directly by determining the quality and quantity of leaf litter and root exudates or indirectly by influencing soil physiochemical properties (Soussi et al, 2016; Chai et al, 2019). However, it is still unclear how soil properties and plant attributes simultaneously drive the local assemblage and distribution of microorganisms.…”