The fungi in the unimproved (low-nitrogen) grasslands of northern Europe are the subject of great conservation interest, as indicators of ecological continuity. The fungi concerned fall into four main groups, the waxcap fungi (Hygrocybe species), the Clavariaceae and similar species, Entoloma species and members of the Geoglossaceae.
Survey and monitoring of many of these fungi is problematic due to the ephemeral and unpredictable appearance of their fruit bodies. Identification is also difficult, as many species are highly variable in size, shape and colour, and cannot be reliably distinguished in the field. A partnership between CABI, Kew and the University of Aberystwyth from August 2010 - January 2013 will investigate the molecular phylogeny of two of the waxcap fungi groups in the UK and carry out preliminary work on their nutritional and mycorrhizal status. The project is being supported financially by DEFRA and Scottish Natural Heritage.
A key requirement for many fungi of conservation concern in the UK is the need for molecular diagnostic tools, to assist in species definition (including recognition of cryptic taxa). Identification of diagnostic (barcoding) sequences will allow detection of non-fruiting populations, a particularly important task bearing in mind the ephemeral and irregular fruiting events of many fungi.
The fungal species of unimproved grasslands have not been studied in any detail using molecular methods. Bearing in mind the critical nature of morphological species definition for many of these fungi, the existence of cryptic species might be expected, and phylogenetic studies would also lead to detection of correlated morphological traits that will improve the robustness of traditional identification methods.
We intend to focus on two genera from the grassland system, the waxcaps themselves (Hygrocybe spp.) and the earthtongues (Geoglossum and relatives). Both groups have been the subject of long-term monitoring exercises, they have excited the attention of non-specialists, their presence has led to some of the few SSSIs in the UK designated for their non-lichenized fungi, and are included in of the sites analyzed in the Important Fungus Areas survey. Three species are included in the BAP signposting exercise (Hygrocybe spadicea, Geoglossum atropurpureum and Microglossum olivaceum), with a further 11 taxa placed on the provisional UK Red Data List for fungi – two of which have been proposed for inclusion in Schedule 1 of the Bern Convention. All four national statutory conservation bodies have funded survey and monitoring of these fungi. Despite all of this interest, neither group has been the subject of a modern systematic revision using molecular methods. Few authentic sequences are available, and the work to identify diagnostic barcode sequences has not been carried out.
We will use freshly gathered samples and authentic material from Kew’s incomparable collections. Fresh collections will be sourced with support from the extensive existing network of local recording groups with interests in waxcap species, and targetted workshops/survey exercises. DNA extraction, sequencing and analysis will be carried out according to standard methods, with preliminary phylogenies based on ITS sequences and additional genes used subsequently to increase the robustness of evolutionary reconstructions. Correlations will be sought between genotypes and morphological/ecological characteristics, focusing on areas of conflict between the new phylogenies and traditional classifications. The outcome will be a stable taxonomic system with potential for use in a wide range of ecological and conservation studies.
This project will give us the capacity to develop novel monitoring methods, as recommended in the UK Strategy for conservation of fungi "Saving the Forgotten Kingdom". Next-generation sequencing approaches allow us to analyze fungal populations extracted directly from soil cores. This makes it possible not only to identify which species are present but also to study their relative abundance. This allows the analysis of non-fruiting fungal communities and can potentially reduce substantially the need for multiple field surveys to detect all the species that may be present. The work may also lead to more robust methodologies for selection of grassland SSSIs. Whilst issues of sampling intensity and the heterogeneous distribution of grassland fungi make it likely that traditional field surveys will still be useful, the ability to generate a species inventory by genetic means holds huge potential for fungal conservation.
This project will allow us to (a) define species using more objective criteria, using a combination of morphological and molecular methods; (b) recognize cryptic species that may need to be considered for conservation management; (c) gain a better understanding of the ecology of waxcap fungi, (d) designate barcode sequences to allow development of novel monitoring tools for non-fruiting populations, and (e) reinvigorate the partnership between the scientific and lay communities to study these beautiful species.