Positive effects of plant diversity on soil microbial biomass and activity are associated with more root biomass production

Abstract

This study aims to explore relationships between plant diversity and soil microbial function and the factors that mediate the relationships. Artificial plant communities (1, 2, 4 and 8 species) were established filled with natural and mine tailing soils, respectively. After 12 months, the plant species richness positively affected the soil microbial functional diversity in both soil environments but negatively affected microbial biomass and soil basal respiration in the natural soil. The root biomass positively correlated with the microbial biomass, cultural bacterial activity and soil basal respiration in both soil environments. Moreover, the D i (deviations between observed performances and expected performances from the monoculture performance of each species of mixture) of microbial biomass, cultural bacterial activity and soil basal respiration positively correlated with the D i of root biomass in both soil environments. Consistent with stress-gradient hypothesis, the D mix (over-function index) of aboveground biomass positively correlated plant species richness in the mine tailing soil. Results suggest that the root biomass production is an important mechanism that affects the effects of plant diversity on soil microbial functions. Different responses of soil microbial function to increasing plant diversity may be due to root biomass production mediated by other factors. ARTICLE HISTORY

Land‐use drives the temporal stability and magnitude of soil microbial functions and modulates climate effects

“…Bardgett et al (1997),Loreau et al (2001),Lucas et al (2013),Wang et al (2017) D Temporal variability of soil microbial biomass is strongly influenced by soil pH in both arable and grassland ecosystems.Wardle (1998) E Climate effects on functional diversity, microbial biomass, and basal respiration are driven by soil moisture and precipitation; climate effects on F/B are generally weak. Liu et al (2009), Strickland and Rousk (2010), Li et al (2017) F Plant diversity strongly affects soil moisture; absence of tillage improves moisture retention in upper soil layer.…”

Trait differences between and within ranges of an invasive legume species

“…Even if one assumed such a correlation, whether increased size confers greater competitive ability against native species in the introduced range would likely depend on whether competition occurs above or belowground. If competitors are indeed the agent of selection on size in the invasive range of M. polymorpha, then the increased investment in belowground biomass by invasive genotypes suggests that size is driven by competition for nutrients or rhizobia in the soil, rather than aboveground competition for light or space (Wang et al, 2017;Eisenhauer et al, 2017).…”

Soil microbial activity in a Mediterranean garrigue responds more to changing shrub community than to reduced rainfall

“…For example, plant roots may have an important role through stronger competition of a denser root system in higher diverse plant communities, which may decrease the availability of certain resources (Eviner and Chapin 2003). For instance, Wang et al (2017) showed that species richness negatively affected the soil microbial biomass and soil basal respiration in artificial plant communities and suggested that higher root biomass production and increased competition for limiting resources were the cause. This could also be the case in our study system, where root growth for a given species is influenced by the identity of neighbors (Shihan et al, personal communication).…”