North Kerry Waxcap Survey 2012 - the Northern Ireland Fungus Group

value beyond mycology. It was noticeable that when comparing waxcap distribution with the
fields found to be most favoured by chough feeding on leatherjackets (Anon, 2004) that they
were completely coincident.
Waxcap grasslands however are often not particularly good for higher plants which can mean
that they are missed when designating sites for nature conservation. Statistical studies in
Sweden have shown that there is a low congruence between the diversity of Hygrocybe spp.
and higher plants (Öster, 2008) indicating that reliance on higher plants when protecting sites
could well miss sites of high mycological value.
The great unknown however is just what these species are actually doing in the soil. One
study (Griffith et al., 2002) points to some possible answers based on stable isotope analysis.
Stable isotopes of Carbon ( 13 C) and Nitrogen ( 15 C) occur naturally and work looking at the
patterns of 13 C and 15 C enrichment in ectomycorrhizal and saprophytic fungi have shown quite
different enrichment patterns. Waxcaps, however, appear different to normal saprophytic fungi
as they are more depleted in 13 C and more enriched in 15 N. Clavarioids and Geoglossaceae
are even more extreme in this trend, but Entolomas are more typical of saprophytic fungi. This
could mean that Hygrocybe spp., Clavarioids and Geoglossaceae could be deep humic
decayers rather than normal surface litter decayers adapted to N poor conditions.
Assessing site quality from fungal data
The first recognition of grassland fungi in Ireland was a paper by (Feehan and McHugh, 1992)
on the Curragh and since the early 1990s, interest has been growing in this group as it has
been recognised that this unique community is seriously threatened across Europe.
Various systems have been proposed to rank sites for grassland sites for their fungal
conservation value. (Rald, 1985) in Denmark proposed a system based on the number of
species of Hygrocybe, (Nitare, 1988) looked at systems in Sweden, (Jordal, 1997) in Norway
and the British Mycological Society instigated a survey giving the surveyed sites a CHEG
score (Clavariaceae, Hygrocybe, Entoloma and Geoglossaceae) (Rotheroe et al., 1996).
Rotheroe then proposed a system that included a weighted score for rarer species that are
restricted to species rich sites (Rotheroe, 1999). This was further developed by McHugh et al
(2002) when we proposed a weighted scoring system for Ireland. One of the main drivers for
this was due the lack of mycological recording in Ireland, we wanted to highlight sites for
further visits that had species thought to be rarer or more valuable indicator species.
Weighting species is controversial as in reality the data is not available to weight them with
confidence (Griffith et al., 2006; Griffith et al., In Press) but the point was to use this in
conjunction with standard CHEG scores and highlight possible interesting sites (McHugh et al.,
2001).
Most of the scoring systems above base their score on species and do not include varieties in
the calculation (Rald, 1985), (Nitare, 1988), (Boertmann, 1995), (Vesterholt et al., 1999) and
(McHugh et al., 2001). However, some surveys have counted varieties (Rotheroe, 1999) and
(Newton et al., 2002) so it is very important to be clear about the basis of the system used
when comparing data across regions. For this purpose, the definition of species used in all the
Irish surveys follows the Checklist of the Basidiomycetes of the British Isles (Legon and
Henrici, 2005) and Spooner’s key for Geoglossaceae (Spooner, 1998) with three exceptions
to remain consistent with the continental surveys.
• Hygrocybe pratensis var. pallida is the only variety included in the scoring following
Vesterholt 1999
• Although the Checklist of the Basidiomycetes of the British Isles (Legon 2005) did list
Hygrocybe conicoides as a species rather than Hygrocybe conica var. conicoides,
Boertmann’s book and his recent interpretation of Hygrocybe in Funga Nordica
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