Tree establishment in ericaceous understory – importance of mycorrhizal networks and guild interactions

The idea that trees benefit from belowground connections through common mycorrhizal networks has recently taken hold in society.

The scientific evidence for functional importance of common mycorrhizal networks in forests is, however, sparse because field experiments that isolate network effects from alternative explanations are difficult to design.

Many ectomycorrhizal fungi form large mycelia that grow intermingled in diverse communities together with roots from multiple trees, and common networks are likely to be widespread in forests, albeit their benefit for seedlings is still unsettled.

The boreal forest also has a dense understory of ericaceous dwarf shrubs, which associate with ericoid mycorrhizal fungi with functional traits that contrast those of ectomycorrhizal fungi.

The overall purpose of this project is to disentangle the effects of mycorrhizal networks, mycorrhizal fungal communities and interactions with understory shrubs on pine seedling performance as well as on longer-term soil organic matter dynamics and nutrient cycling in boreal forest.

The project uses a unique ongoing field experiment with factorial elimination of shrubs and pine roots and implement the most updated approach to isolate effects of mycorrhizal networks on seedling performance.

The project also investigates fungal functional traits based on a novel meta-transcriptomics and evaluates long-term consequences of mycorrhizal guild interactions on soil organic matter quality and stocks.