Plant genotype controls wetland soil microbial functioning in response to sea-level rise
Abstract. Climate change can strongly alter soil microbial functioning via
plant–microbe interactions, often with important consequences for ecosystem
carbon and nutrient cycling. Given the high degree of intraspecific trait
variability in plants, it has been hypothesized that genetic shifts within
plant species yield a large potential to control the response of
plant–microbe interactions to climate change. Here we examined if sea-level
rise and plant genotype interact to affect soil microbial communities in an
experimental coastal wetland system, using two known genotypes of the
dominant salt-marsh grass Elymus athericus characterized by differences in their sensitivity
to flooding stress – i.e., a tolerant genotype from low-marsh environments
and an intolerant genotype from high-marsh environments. Plants were exposed
to a large range of flooding frequencies in a factorial mesocosm experiment,
and soil microbial activity parameters (exo-enzyme activity and litter
breakdown) and microbial community structure were assessed. Plant genotype
mediated the effect of flooding on soil microbial community structure and
determined the presence of flooding effects on exo-enzyme activities and
belowground litter breakdown. Larger variability in microbial community
structure, enzyme activities, and litter breakdown in soils planted with the
intolerant plant genotype supported our general hypothesis that effects of
climate change on soil microbial activity and community structure can depend
on plant intraspecific genetic variation. In conclusion, our data suggest
that adaptive genetic variation in plants could suppress or facilitate the
effects of sea-level rise on soil microbial communities. If this finding
applies more generally to coastal wetlands, it yields important implications
for our understanding of ecosystem–climate feedbacks in the coastal zone.
期刊:
Biogeosciences
2021
作者:
Peter Mueller,Fabian Horn,Kai Jensen,Stefanie Nolte,Svenja Reents,Susanne Liebner,Hao Tang
DOI:10.5194/bg-18-6133-2021
