Are there keystone ectomycorrhizal fungi that mediate tree invasion of lowland heathlands? - COMPLETED 2008
Ectomycorrhizal fungi are essential symbiotic partners of the vast majority of temperate trees. These fungi play a critical role in plant nutrition by exchanging mineral nutrients captured from the soil for access to plant organic carbon. However, we know surprisingly little about how the availability of ectomycorrhizal fungi affects the establishment of tree seedlings in natural environments. Heathlands are unique ecosystems that are threatened worldwide by ectomycorrhizal tree invasion. The trees shade out native heath shrubs and eventually the heathland becomes woodland. In the British Isles, heathlands are a cherished component of the landscape and they are high-profile habitats for biodiversity and conservation. Lowland heathlands have experienced the most dramatic decline in the last century, largely due to invasion by birch and pine, both of which are obligately ectomycorrhizal trees.
Starting in 2005 and continuing until 2008, this study used a combined field and laboratory approach to uncover the distribution of ectomycorrhizal fungi in lowland heaths and unravel the initial symbiotic events involved with tree establishment. We relied heavily on molecular ecology approaches because ectomycorrhizal fungi are diverse and, although often large and long-lived, they are largely cryptic organisms. At the time of this study, these powerful approaches had been rarely applied to the study of British ectomycorrhizal fungi. Our results were broadly relevant because they were being carried out throughout multiple seasons at different locations, they were amenable to comparison with other heathland systems, and they provided stepping stones for performing ecologically-significant work in the future aimed at addressing ectomycorrhizal tree invasion of heathlands.
- Collier, F.A. & Bidartondo, M.I. (2009). Waiting for fungi: the ectomycorrhizal invasion of lowland heathlands. Journal of Ecology 97, 950–963
- Collier, F.A. (2009). The mycorrhizal fungi involved in the tree invasion of lowland heathlands. PhD Thesis, Imperial College London, England.