Pine invasion drives loss of soil fungal diversity. Is there a chance of recovery following pine removal?
Sarah J. Sapsford , A. Wakelin, D. A. Peltzer, I. A. Dickie
Harry Butler Institute, Murdoch University, Western Australia; School of Biological Sciences, University of Canterbury, Christchurch, New Zealand

The widespread co-invasion of non-native pine trees with their non-native ectomycorrhizal fungi causes a loss of both aboveground plant diversity and belowground soil fungal communities. The effects of pine invasions on an ecosystem can also remain as legacies even after the plant species have been removed. Our aim was to determine whether the below-ground legacies of pine persist in an ecosystem and, if so, for how long. We also aimed to determine whether removal of pine at a specific density exacerbates legacies. We sampled soils across 22 sites on the South Island of New Zealand and extracted and sequenced for fungi from each sample. We determined that legacies of pine persist in the soil for quite a few years after pine removal. Specifically, fungal species that are closely associated with pines, and are necessary for pines to establish in an area, can remain in the soil for at least 5 years after removal. It is possible these fungal species may be persisting on scattered reinvading pine seedling or trees that were not completely killed during removal. The persistence of these pine-associated fungi may allow future reinvasion.