Edaphic properties related with changes in diversity and composition of fungal communities associated with Pinus radiata

Effective symbiosis with ectomycorrhizal (ECM) fungi is important for the successful growth and establishment of Pinus radiata. However, the structure of ECM communities varies across soil (edaphic) and environmental conditions, and thus affects the potential range of symbiotic associations. To improve our understanding of these factors, we characterised the range of ECM fungi present across six sites varying in edaphic properties. We also assessed ECM fungi in root tips of P. radiata planted two years earlier at these sites to assess the extent in overlap between root and soil ECM communities. The structure of the ECM community varied substantially with site. Across all sites, correlations were identified between soil pH and metrics describing ECM community structure in both soil and root samples, indicating soil pH was contributing to the differences in the fungal communities between sites. Mineralisable nitrogen, soil carbon, and phosphorus content also varied with site, but were not significantly related to descriptors of the ECM communities. Root tips and surrounding soils shared some taxa but were inhabited by diverse communities of fungi, and a number of ECM P. radiata associations unique to New Zealand were identified. It is possible that the establishment of linkages between metrics could provide an opportunity to begin predicting the response of ECM populations to site modification, and potentially increase the growth of radiata pine and improve forest health through enhanced resilience to disturbance.