Fungal Ecology of Temperate Rainforest habitats

Abstract

The Celtic rainforests of Wales are ancient, biodiverse woodlands found along the west coast, part of the temperate rainforest ecosystem. Once widespread, they are now fragmented, mostly surviving in steep valleys. These rainforests face significant threats from habitat loss, invasive species, and diseases, particularly affecting native oak species (Quercus petraea and Quercus robur). This thesis investigates fungal diversity within the Celtic rainforests of Wales, comparing it to broader Welsh oak woodlands using environmental DNA (eDNA) metabarcoding. The study integrates leaf, soil, and air samples collected from both temperate oak woodlands and the unique temperate rainforest ecosystem to examine fungal community structure.

Contrary to initial expectations, fungal richness did not significantly differ between the two ecosystems, but their fungal assemblages were distinct. Ectomycorrhizal fungi were more abundant in soil samples from temperate rainforest sites, while foliar pathogens like Erysiphe alphitoides were less common on oak leaves in the rainforests. Air samples revealed distinct seasonal variations in fungal DNA abundance. The study also explored the
impact of anthropogenic factors, such as atmospheric nitrogen deposition, on fungal communities. A strong positive correlation was found between E. alphitoides abundance and nitrogen dioxide (NO2) levels, suggesting that urban pollution exacerbates fungal pathogen proliferation. Nitrogen fertilization trials on oak saplings further indicated enhanced pathogen severity and altered growth dynamics, pointing to nitrogen enrichment’s influence on oakfungal interactions.

The study advances the use of eDNA metabarcoding for monitoring fungal biodiversity, highlights the effects of environmental stressors on fungal communities, and provides a detailed ecological profile of Welsh oak woodlands. This research offers valuable insights for conservation efforts focused on these unique and threatened ecosystems

Date of Award	2025
Original language	English
Awarding Institution	Aberystwyth University
Sponsors	Llywodraeth Cymru KESS-2
Supervisor	Gareth Griffith (Supervisor)