Leaf bacterial diversity mediates plant diversity and ecosystem function relationships

Abstract

Research on biodiversity and ecosystem functioning has demonstrated links between plant diversity and ecosystem functions such as productivity. At other trophic levels, the plant microbiome has been shown to influence host plant fitness and function, and host-associated microbes have been proposed to influence ecosystem function through their role in defining the extended phenotype of host organisms However, the importance of the plant microbiome for ecosystem function has not been quantified in the context of the known importance of plant diversity and traits. Here, using a tree biodiversity-ecosystem functioning experiment, we provide strong support for the hypothesis that leaf bacterial diversity is positively linked to ecosystem productivity, even after accounting for the role of plant diversity. Our results also show that host species identity, functional identity and functional diversity are the main determinants of leaf bacterial community structure and diversity. Our study provides evidence of a positive correlation between plant-associated microbial diversity and terrestrial ecosystem productivity, and a new mechanism by which models of biodiversity-ecosystem functioning relationships can be improved.

Plant host identity and soil macronutrients explain little variation in sapling endophyte community composition: Is disturbance an alternative explanation?

“…Bacterial endophyte communities could exhibit broad overlap among host tree species, which occur among conifer species in western North America (Carrell, Carper, & Frank, ; Carrell & Frank, ). Conversely, bacterial endophyte communities may be highly host‐specific, which matches our current understanding of leaf epiphyte communities (Kembel et al, ; Kim et al, ; Laforest‐Lapointe, Meisier, & Kembel, ; Laforest‐Lapointe, Paquette, Messier, & Kembel, ; Lambais et al, ). If high specificity is typical, this may have profound implications for plant performance because plant species can vary dramatically in susceptibility to their bacterial endophytes, which are often pathogens (Griffin et al, ; Griffin, Wright, Morin, & Carson, ).…”

Ectomycorrhizal fungal diversity predicted to substantially decline due to climate changes in North American Pinaceae forests

“…ECMF differ in foraging and dispersal strategy and enzymatic abilities, which can lead to a positive relationship between ECMF diversity and seedling growth from a range of 1–4 ECMF species in experimental tree seedlings (Baxter & Dighton, , ). Recent work suggests that species loss results in declines in ecosystem productivity and resiliency across a broad range of taxa (Duffy et al, ), including plant–microbial symbionts (Laforest‐Lapointe et al, ). However, it remains unclear how a system with ~100 ECMF species will respond to a 25%–30% loss or gain in ECMF diversity.…”

“…Forecasting changes in the diversity and composition of microbial communities under anticipated future climates is valuable for concentrating conservation efforts (van der Linde et al, ) and predicting changes to ecosystem function (Bissett, Brown, Siciliano, & Thrall, , Duffy et al, , Koide, Fernandez, & Malcolm, ). Loss of host species results in decreased ecosystem productivity and stability across a broad range of taxa (Duffy et al, ), including effects on microbes (Duffy et al, , Laforest‐Lapointe et al, ). Recent advances in molecular methods have made it possible to characterize current continental‐scale diversity patterns of soil microbes (van der Linde et al, ; Talbot et al, ; Tedersoo et al, ; Tedersoo, Bahram, et al, ).…”

Temporal dynamics of soil bacterial communities and multifunctionality are more sensitive to introduced plants than to microbial additions in a multicontaminated soil

“…Because of the disparate soil enzyme activities and physicochemical properties, we divided soil ecosystem multifunctionality into two groups: multienzyme activities (PPO, DHA, and UE) and multinutrient levels (AN, AK, and AP). We then quantified the multifunctionality index for each soil sample using the first axis of a principal component analysis (this explained 80% of the variation in these two groups of variables) according to Laforest‐Lapointe, Paquette, Messier, and Kembel ().…”