Changes in fungal community of Scots pine (Pinus sylvestris) needles along a latitudinal gradient in Sweden

• The fungal community of Scots pine needles was studied using 454-sequencing.
• Fungal community composition changed gradually along a latitude gradient.
• Healthy needles in natural stands displayed a reversed latitude diversity gradient.
• Diseased needles hosted a more diverse fungal flora compared to healthy needles.
• Two cryptic species within Lophodermium pinastri were detected.

Conifer needles are typically long lived and can host a diverse community of fungal species with various effects on their host tree. The purpose of this study was to analyse shifts in the fungal community of Scots pine (Pinus sylvestris) needles on different spatial scales using 454 pyrosequencing. The fungal community composition changed gradually along a north-south gradient through Sweden, representing boreal to temperate vegetation zones. OTU richness and Shannon's diversity index increased with increasing latitude, but only in naturally regenerated forests. On the tree level, needles with symptoms of disease hosted a more diverse mycobiota compared to healthy needles, presumably supporting more pathogenic or saprotrophic species. This study provides a better insight into the patterns of fungal communities of Scots pine needles and highlights the need for further experimental research to identify specific environmental factors shaping the abundance of different fungal species.