PS 81-209
Metagenomic assessment of soil fungal community variation in native and introduced maples
Nearly 1/3 of Pennsylvania’s vascular flora is composed of plant species not native to North America. A small subset of these non-native species have exhibited extremely high population growth rates and become prolific in their new range.
Despite extensive research, few generalizations have been found to explain or predict which introduced plant species become weedy. Although numerous studies have examined the role of species interactions in this process, the majority of these studies have focused on aboveground competitors, herbivores, and pathogens. The purpose of our study was to elucidate patterns in belowground fungal communities of maples (Sapindaceae : Acer) that may contribute to weediness. As described by Moora and colleagues (2011) we expected to find (1) a greater diversity of soil fungi associated with native species compared to introduced species which should have fewer co-adapted associates and (2) that weedy plants should be associated with common widespread fungal taxa, while rare fungal taxa would be more often associated with benign species.
Rhizospheric soil samples were collected for five species of maples from six sites across central Pennsylvania. The highly variable ITS region was sequenced on the Illumina platform and fungal community composition was quantified and compared using QIIME and USEARCH.
Results/Conclusions
We found 4,477 OTUs across all samples. Among these we found core fungal communities of introduced maples (as a group) were a reduced subset of the communities found with native maples (75% of core community members of introduced species were also part of core assemblage of native species). However, when looking species by species, the different introduced maples often had fungal assemblages as diverse as the native species.
Although we observed greater similarity in the fungal communities among weedy species than among benign species (there was a larger core microbiome for weedy species), we also found that each weedy species had a rich unique core community.
How, or whether, any of the differences observed here mechanistically contribute to invasiveness in general is an open question. Although we found predicted differences between some of the individual species, taken as a group, there appear to be few commonalities between native or non-native species, or weedy or benign species. Furthermore, this in situ study doesn’t tell us whether fungal community differences are imparting different demographic abilities to the maples or whether the inherent differences in the maples are driving the variations in fungal communities (controlled field experiments are planned to address this).