Invasive plants differentially affect soil biota through litter and rhizosphere pathways: a meta‐analysis

Abstract

Invasive plants affect soil biota through litter and rhizosphere inputs, but the direction and magnitude of these effects are variable. We conducted a meta‐analysis to examine the different effects of litter and rhizosphere of invasive plants on soil communities and nutrient cycling. Our results showed that invasive plants increased bacterial biomass by 16%, detritivore abundance by 119% and microbivore abundance by 89% through litter pathway. In the rhizosphere, invasive plants reduced bacterial biomass by 12%, herbivore abundance by 55% and predator abundance by 52%, but increased AM fungal biomass by 36%. Moreover, CO2 efflux, N mineralisation rate and enzyme activities were all higher in invasive than native rhizosphere soils. These findings indicate that invasive plants may support more decomposers that in turn stimulate nutrient release via litter effect, and enhance nutrient uptake by reducing root grazing but forming more symbioses in the rhizosphere. Thus, we hypothesise that litter‐ and root‐based loops are probably linked to generate positive feedback of invaders on soil systems through stimulating nutrient cycling, consequently facilitating plant invasion. Our findings from limited cases with diverse contexts suggest that more studies are needed to differentiate litter and rhizosphere effects within single systems to better understand invasive plant‐soil interactions.

Enhanced activity of soil nutrient‐releasing enzymes after plant invasion: a meta‐analysis

“…This positive priming of soil microbial activity after extra energy inputs to soil has been widely reported (Kuzyakov 2010, Xiao et al 2015, and our analysis also found that invaded soils have significantly higher soil microbial biomass and basal respiration than noninvaded soils (Appendix S1: Fig. S5), suggesting higher activities of soil microbes after plant invasion (Zhang et al 2019). In specific examples, invasive plants have been shown to secrete root exudates actively that are rich in amino acids and proteins (Bais et al 2006).…”

“…S5), suggesting higher activities of soil microbes after plant invasion (Zhang et al. ). In specific examples, invasive plants have been shown to secrete root exudates actively that are rich in amino acids and proteins (Bais et al.…”

Contrasting latitudinal clines of nematode diversity in Spartina alterniflora salt marshes between native and introduced ranges

“…Belowground organisms play important roles in regulating ecosystem functioning in terrestrial ecosystems (Bardgett & van der Putten, 2014; Zhang, Li, Wu, & Hu, 2019), mediating the cycling of carbon and other elements, and affecting aboveground community dynamics (Morriën et al, 2017). Compared with the well‐known geographic patterns in the diversity and abundance of aboveground organisms (Hillebrand, 2004; Mannion, Upchurch, Benson, & Goswami, 2014), the geographic patterns of belowground organisms are relatively understudied (but see Decaëns, 2010; Hendershot, Read, Henning, Sanders, & Classen, 2017; Maraun, Schatz, & Scheu, 2007).…”

A survey of invasive plants on grassland soil microbial communities and ecosystem services

“…Changes in plant species composition affect the quantity and quality of root exudates to the soil 1-3 alter rates of nutrient cycling [4][5][6] , and change inputs of organic matter to the soil 1 . Despite an increasing knowledge of how invasive plants change these soil properties, relatively little is known about how invasive plants influence soil microbial community structure and function 2,4,5,7,8 . Changes in the chemical and physical properties of soil, as well as in litter and exudate inputs, are almost certain to impact microbial community assembly processes and community composition, which in turn, will alter ecosystem services.…”