Plant community composition is influenced by successional stage of the soil community

Background/Question/Methods

The soil community has been shown to contribute to the maintenance of plant diversity however the role of the soil community in causing shifts in plant community composition over time is less well understood.  We evaluated the effect of soil communities collected from an early secondary successional field and a late successional field on plant communities constructed from four plant families, with representatives of early through late successional species.   We also included an AMF only soil treatment in order to evaluate the relative impact of AMF on plant community composition. 

Results/Conclusions

We found that soils containing AMF promoted plant diversity (F_3,37=12.72, p<0.0001) and belowground productivity (F_3,37=12.28, p<0.0001).  Soils containing AMF also promoted biomass production in mid- and late successional plants (F _1,37=24.26, p<0.0001 and F _1,37=11.24, p<0.05, respectively), but not in early successional plants.  Early successional plants performed better in the late successional soil community (F _1,37=7.49, p<0.05), while late successional plants performed better in the early successional soil community (F _1,37=4.43, p<0.05); a response we attribute to greenhouse conditions exacerbating the effects of host-specific pathogens.  Our results present additional evidence suggesting that the soil community is vital to  structuring plant communities and contributes to understanding whether the soil community drives plant community transition during succession.