Microbial ecology of biological invasions

Abstract

Invasive microbes, plants and animals are a major threat to the composition and functioning of ecosystems; however, the mechanistic basis of why exotic species can be so abundant and disruptive is not well understood. Most studies have focused on invasive plants and animals, although few have considered the effects of invasive microbes, or interactions of invasive plant and animal species with microbial communities. Here, we review effects of invasive plants on soil microbial communities and discuss consequences for plant performance, plant community structure and ecosystem processes. In addition, we briefly discuss effects of invasive soil microbes on plant communities, which has been less well studied, and effects of invasive animals on soil decomposers and ecosystem functioning. We do this by considering each of three important functional groups of microbes, namely soil microbial parasites and pathogens, mutualistic symbionts and decomposers. We conclude that invasive plants, pathogenic and symbiotic soil microbes will have strongest effects on the abundance of individual species, community diversity and ecosystem functioning. Invasive decomposer microbes probably have little impact, because of limited specificity and great functional redundancy. However, invasive plants and animals can have major effects on microbial decomposition in soil. We propose that understanding, predicting and counteracting consequences of enhanced global homogenization of natural communities through introducing exotic plants, animals and microbes will require future studies on how pathogenic, symbiotic and decomposer soil microbes interact, how they are influenced by higher trophic level organisms and how their combined effects are influencing the composition and functioning of ecosystems.

Fungal Assemblages Associated with Roots of Halophytic and Non-halophytic Plant Species Vary Differentially Along a Salinity Gradient

“…Conversely, the generalist I. viscosa, which can be acting as an invasive plant in the surroundings of the salt marsh due to some degree of habitat degradation [36], presented a single, general association of endophytes capable to withstand diverse physical conditions. Analogous phenomena have been observed in the interaction between plants and root-feeding nematodes: While invasive plant species occupying the habitat of native species are mostly colonized by generalist nematodes, the latter is most commonly colonized by feeding specialists [37].…”

Alien species in a warmer world: risks and opportunities

“…Lack of knowledge and research needs Most of the current information about range shifts and invasions comes from the plant and animal kingdoms, whereas little is known about invasions of alien microorganisms [85]. For example, modern forestry practice uses commercial mixtures of symbiotic ectomycorrhizal fungi for successful establishment of trees in silviculture [86], transporting them away from their native distribution range.…”

Rhododendron aureum Georgi formed a special soil microbial community and competed with above‐ground plants on the tundra of the Changbai Mountain, China

“…Soil microbes play a key role in ecosystems and mediate many ecological processes that are critical to decomposition, nutrient cycling, and plant community dynamics(Fierer et al., 2012; Van der Putten, Klironomos, & Wardle, 2007). In addition, they can act as a source and sink for plant nutrients (Nannipieri et al., 2012).…”