Rust Fungus Red Data List and Census Catalogue for Wales

The rust fungi are a group of specialised plant pathogens. Conserving them seems to fly in the face of reason. Yet as our population grows and food supplies become more precarious, controlling pathogens of crop plants becomes more imperative. Breeding resistance genes into such plants has proved to be the most cost effective solution. Such resistance genes evolve only in plants challenged by pathogens. We hope this report will assist in prioritising the conservation of natural ecosystems and traditional agro-ecosystems that are likely to be the richest sources of resistance genes. Despite its small size (11% of mainland Britain) Wales has supported 225 rust fungi taxa (including 199 species) representing 78% of the total British mainland rust species. For the first time using widely accepted international criteria and data collected from a number of mycologists and institutions, a Welsh regional threat status is offered for all native Welsh rust taxa. The results are compared with other published Red Lists for Wales. Information is also supplied in the form of a census catalogue, detailing the rust taxa recorded from each of the 13 Welsh vice-counties. Of the 225 rust taxa so far recorded from Wales 7 are probably extinct (3% of the total), and 39 (18%) are threatened with extinction. Of this latter total 13 taxa (6%) are considered to be Critically Endangered, 15 (7%) to be Endangered and 13 (6%) to be Vulnerable. A further 20 taxa (9%) are Near Threatened, whilst 15 taxa (7%) lacked sufficient data to permit evaluation. Just over a third of Welsh rust fungi taxa require some form of action, either to better understand their status, or reverse known ongoing declines. This is a similar figure to those presented elsewhere for bryophytes and lichens but higher than the 19% of vascular plants requiring action.