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Fungi in the Burren
Field Mycology Volume 2(1), January 2001
FUNGI IN THE BURREN Tom Harrington Department of Life Sciences, University of Limerick, Limerick, Ireland
summer and autumn. Most of the survey is located on the northern and eastern hills. Ten permanent plots have been included in the survey since 1997.
Introduction he Burren, a 250 square kilometre area of karstic limestone in western Ireland, is famous for its remarkable flora which combines arctic-alpine and Mediterranean plants growing in close association. Recent work has shown moreover that the Burren also harbours an unusual macromycete biota associated with mountain avens (Dryas octopetala) (Harrington, 1996). Dryas, which has survived in the Burren since the last glaciation, is very abundant here, from sea level to the summits of the hills (ca. 300m) and it dominates the grass-heath vegetation of higher ground. In arctic and alpine environments Dryas is associated with many specialised arctic-alpine fungi for example Lactarius dryadophilus and Marasmius epidryas. Since 1992 I have surveyed the macromyctes of Dryas vegetation in late
T
The Fungi A total of 96 species of macromycetes have been recorded to date. Cortinarius is the largest genus represented (19 species) followed by Entoloma (4) and Hygrocybe (7). No arctic-alpine fungi have so far been found in the Burren. The most unusual feature of the biota however is the presence of 35 basidiomycetes which are normally mycorrhizal on forest trees. Most of these have not previously been found in association with Dryas, notably: Cantharellus aurora, Cortinarius croceocaeruleus, C. spilomeus, C. cinnamomeus, C. brunneus, Lactarius citriolens, L. deliciosus, L. uvidus, L. zonarius, Boletus luridus, B. erythropus, Hebeloma sinapizans, H. circinans,
Cantharellus aurora, the most abundant species forming mycorrhiza with Dryas on the Burren, clearly showing the shallowly wrinkled undersurface. Photograph © T. Harrington.
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Field Mycology Volume 2(1), January 2001 coniferarum, C. mussivus and C. odorifer which have not been previously recorded growing with Dryas. C. caesiocanescens is associated mainly with pine in Central Europe. In Northern Europe, C. odorifer and C. mussivus are typical of pine forests on calcareous ground (Brandrud et al., 1990, 1992) although C. odorifer associates with pines as far south as the Mediterranean (Malençon & Bertault, 1970). C. atrovirens (see back cover) is an Abies associate in Central Europe but occurs with pine in Northern Europe. The rest of the macromycetes of the Dryas heaths are woodland or grassland saprotrophs. Collybia dryophila, Mycena pura, M. alcalina, Marasmius androsaceus, Hygrocybe The spectacular Cortinarius odorifer, a species with a strong odour of nitrata, H. virginea var. anise, is usually associated with conifers but is found with Dryas on the virginea, Melanoleuca Burren.Photograph © T. Harrington. grammopodia and M. exscissa are very Hydnum repandum, Tricholoma scalpturatum, common. Clitocybe costata, C. fragrans, C. and T. myomyces. Craterellus aurora, which geotropa and C. nebularis are frequent. occurs in almost every Dryas mat in the Clitopilus prunulus, Lepista nuda and L. luscina Burren, is normally found in boreal and are found sporadically. Entoloma serrulatum montane conifer forests in other parts of and E. sericeum are very common while other Europe. It used to be known as Cantharellus Entoloma spp. are of sporadic occurrence (E. (or Craterellus) lutescens, but is not the same bloxamii, E. incana, E. roseum, and E. sarcituas the common C. tubaeformis var. lutescens. lum among others). The diversity of this Hebeloma circinans, a species of montane group in the Burren merits more intensive coniferous forests in Europe, has previously study. been recorded with Dryas in the Alps. Most intriguing of all however is the Ecological considerations presence of five species of Cortinarius sub- The 15 most common fungi encountered in genus Phlegmacium: C. atrovirens, C. caesio- the plots are shown in Table 1. Cantharellus canescens, C. calochrous ssp. coniferarum var. aurora was far the most abundant species and 31
Field Mycology Volume 2(1), January 2001 was also the most former on Dryas.
fungi is the presence of so many woodland mycorrhizal species even though the area is devoid of trees. This is primarily due to the prolific ability of Dryas to form mycorrhizas with a wide range of basidiomycetes. A cursory survey of the literature indicates that Dryas is associated in arctic-alpine habitats with over 100 putative mycorrhizal fungi including many specialised arctic-alpine fungi, particularly in the genera Cortinarius, Russula, Lactarius, Inocybe and Hebeloma. Some of these fungi may have occurred with Dryas in the Burren in late glacial times but do not seem to be found here today. Instead the 'Dryas niche' in the Burren has been occupied by forest fungi including many mycorrhizal species. Forest mycorrhizal fungi such as Boletus edulis and Cortinarius infractus have in fact been recorded previously with D. octopetala in North America and Europe, in areas devoid of forest cover (Kühner and Lamoure, 1986). However, the assemblage of forest fungi with Dryas in the Burren is unusual because one would typically expect to find such an assemblage in calcareous pine or spruce woods in continental Europe. Cortinarius atrovirens, C. caesiocanescens, C. mussivus and C. odorifer have not been recorded in Ireland outside the Burren region (Muskett and Malone, 1980). Scots pine woodland disappeared from the Burren at least 2,500 years ago and much earlier in the rest of Ireland. Is it possible that these Dryas fungi are remnants of a long-extinct pine forest mycota? Survival of a relict forest mycobiota in a secondary plant community has been observed elsewhere albeit on a shorter time scale, for example in the secondary Arctostaphylos uva-ursi community of cleared Douglas fir forest in the Pacific Northwest (Molina and Trappe, 1982). Similarly, Watling (1981) has observed that Salix repens communities on former woodland areas in Scotland support many woodland fungi. However if the Burren mycota (or at least the woodland component) is a remnant, it is rather surprising that some genera such as Russula and Inocybe do not appear to be represented at all, even though both form mycorrhizas on Dryas and are well represented in calcareous pine woods.
aggressive mycorrhiza-
Table 1 Species Cantherellus aurora Boletus luridus Cortinarius odorifer Collybia dryophila Cortinarius calochrous Cortinarius infractus Cortinarius brunneus Cortinarius caesiocanescens Cortinarius lepidopus Stropharia semiglobata Entoloma serrulatum Cortinarius cinnamomeobadius Entoloma sericeum Mycena pura Cortinarius mussivus
%* 43.5 9.1 9.0 4.4 3.5 3.1 3.0 2.3 2.3 2.1 1.9 1.5 1.4 1.1 0.9
*% of total sporocarp biomass over 3 years sampling
Thirteen fungi have been shown from DNA and morphological evidence to be mycorrhizal on Dryas in the Burren. Fourteen other mycorrhizal morphotypes found on Dryas roots have not yet been positively identified as mycorrhizas of any member of the "sporocarp community". Mycorrhizas of some common species such as Boletus luridus and Cortinarius spilomeus have not been positively identified on Dryas at all and it is possible that these are mycorrhizal on other hosts, for example Helianthemum canum or Arctostaphylos uva-ursi, both of which have a much more restricted distribution in the Burren than Dryas. The diversity of fungi in the Burren, the grassland saprotrophs and Entoloma in particular, has tended to fluctuate greatly between years and with location. On higher ground where the soils are very shallow and organic, Dryas is abundant, and the woodland saprotrophs and mycorrhizal fungi are predominant. Lower areas have soils with a higher mineral content and support a grassy vegetation with less Dryas and a greater diversity of grassland saprotrophs. Discussion The most unusual feature of the Dryas-heath 32
Field Mycology Volume 2(1), January 2001 Malençon, G. & Bertault, R. (1970). Flore des Champignons Supérieurs du Maroc.Tome 1. Rabat. Molina, R. & Trappe, J.M. (1982). Lack of mycorrhizal specificity by the ericaceous hosts Arbutus menziesii and Arctostaphylos uva-ursi. New Phytologist 90, 495-509. Muskett, A.E. & Malone, J.P. (1980). Catalogue of Irish fungi-II Hymenomycetes. Proceedings of the Royal Irish Academy 80(B), 197-276. Watling. R, (1981). Relationships between macromycetes and the development of higher plant communities. In: The Fungal Community. Its Organization and Role in the Ecosystem.Wicklow, D.T. & Carroll, G.C. (eds). NY.
Acknowledgements I wish to thank Tor Erik Brandrud, Roy Watling, Hubert Fuller and David Mitchel for their help and advice. References Brandrud, T.E., Lindström, H., Marklund, H., Melot, J. & Muskos, S. (1990, 1992). Cortinarius, Flora Photographica. Vol. 1 and 2. Cortinarius HB, Matfors, Sweden. Harrington,T. (1996). Observations on the macrofungi of Dryas communities in the Burren, western Ireland. Irish Naturalists Journal 24(10), 413-414. Kühner, R. & Lamoure, D. (1986). Catalogue des Agaricales (Basidiomycetes) de la zone alpine du parc national de la Vanoise et des régions limitrophes. Travaux Scientifique du Parc National de laVanoise. 15, 103-187.
[Editor’s note: The photograph labelled Cortinarius odorifer in Notes and Records in the last issue of FM on page 135 is almost certainly C. dionysae, another species with a strong odour but of meal instead of anise. It differs also in its blue tints in the stem and duller ochre colours in cap and stem base. C. dionysae was also recorded on the recent Fermanagh foray in Northern Ireland.]
The dramatic landscape of the Burren in Western Ireland, home to a unique assemblage of fungi growing in association with mountain avens (Dryas octopetala). Photograph © T. Harrington.
33
FUNGI IN THE BURREN Tom Harrington Department of Life Sciences, University of Limerick, Limerick, Ireland
summer and autumn. Most of the survey is located on the northern and eastern hills. Ten permanent plots have been included in the survey since 1997.
Introduction he Burren, a 250 square kilometre area of karstic limestone in western Ireland, is famous for its remarkable flora which combines arctic-alpine and Mediterranean plants growing in close association. Recent work has shown moreover that the Burren also harbours an unusual macromycete biota associated with mountain avens (Dryas octopetala) (Harrington, 1996). Dryas, which has survived in the Burren since the last glaciation, is very abundant here, from sea level to the summits of the hills (ca. 300m) and it dominates the grass-heath vegetation of higher ground. In arctic and alpine environments Dryas is associated with many specialised arctic-alpine fungi for example Lactarius dryadophilus and Marasmius epidryas. Since 1992 I have surveyed the macromyctes of Dryas vegetation in late
T
The Fungi A total of 96 species of macromycetes have been recorded to date. Cortinarius is the largest genus represented (19 species) followed by Entoloma (4) and Hygrocybe (7). No arctic-alpine fungi have so far been found in the Burren. The most unusual feature of the biota however is the presence of 35 basidiomycetes which are normally mycorrhizal on forest trees. Most of these have not previously been found in association with Dryas, notably: Cantharellus aurora, Cortinarius croceocaeruleus, C. spilomeus, C. cinnamomeus, C. brunneus, Lactarius citriolens, L. deliciosus, L. uvidus, L. zonarius, Boletus luridus, B. erythropus, Hebeloma sinapizans, H. circinans,
Cantharellus aurora, the most abundant species forming mycorrhiza with Dryas on the Burren, clearly showing the shallowly wrinkled undersurface. Photograph © T. Harrington.
30
Field Mycology Volume 2(1), January 2001 coniferarum, C. mussivus and C. odorifer which have not been previously recorded growing with Dryas. C. caesiocanescens is associated mainly with pine in Central Europe. In Northern Europe, C. odorifer and C. mussivus are typical of pine forests on calcareous ground (Brandrud et al., 1990, 1992) although C. odorifer associates with pines as far south as the Mediterranean (Malençon & Bertault, 1970). C. atrovirens (see back cover) is an Abies associate in Central Europe but occurs with pine in Northern Europe. The rest of the macromycetes of the Dryas heaths are woodland or grassland saprotrophs. Collybia dryophila, Mycena pura, M. alcalina, Marasmius androsaceus, Hygrocybe The spectacular Cortinarius odorifer, a species with a strong odour of nitrata, H. virginea var. anise, is usually associated with conifers but is found with Dryas on the virginea, Melanoleuca Burren.Photograph © T. Harrington. grammopodia and M. exscissa are very Hydnum repandum, Tricholoma scalpturatum, common. Clitocybe costata, C. fragrans, C. and T. myomyces. Craterellus aurora, which geotropa and C. nebularis are frequent. occurs in almost every Dryas mat in the Clitopilus prunulus, Lepista nuda and L. luscina Burren, is normally found in boreal and are found sporadically. Entoloma serrulatum montane conifer forests in other parts of and E. sericeum are very common while other Europe. It used to be known as Cantharellus Entoloma spp. are of sporadic occurrence (E. (or Craterellus) lutescens, but is not the same bloxamii, E. incana, E. roseum, and E. sarcituas the common C. tubaeformis var. lutescens. lum among others). The diversity of this Hebeloma circinans, a species of montane group in the Burren merits more intensive coniferous forests in Europe, has previously study. been recorded with Dryas in the Alps. Most intriguing of all however is the Ecological considerations presence of five species of Cortinarius sub- The 15 most common fungi encountered in genus Phlegmacium: C. atrovirens, C. caesio- the plots are shown in Table 1. Cantharellus canescens, C. calochrous ssp. coniferarum var. aurora was far the most abundant species and 31
Field Mycology Volume 2(1), January 2001 was also the most former on Dryas.
fungi is the presence of so many woodland mycorrhizal species even though the area is devoid of trees. This is primarily due to the prolific ability of Dryas to form mycorrhizas with a wide range of basidiomycetes. A cursory survey of the literature indicates that Dryas is associated in arctic-alpine habitats with over 100 putative mycorrhizal fungi including many specialised arctic-alpine fungi, particularly in the genera Cortinarius, Russula, Lactarius, Inocybe and Hebeloma. Some of these fungi may have occurred with Dryas in the Burren in late glacial times but do not seem to be found here today. Instead the 'Dryas niche' in the Burren has been occupied by forest fungi including many mycorrhizal species. Forest mycorrhizal fungi such as Boletus edulis and Cortinarius infractus have in fact been recorded previously with D. octopetala in North America and Europe, in areas devoid of forest cover (Kühner and Lamoure, 1986). However, the assemblage of forest fungi with Dryas in the Burren is unusual because one would typically expect to find such an assemblage in calcareous pine or spruce woods in continental Europe. Cortinarius atrovirens, C. caesiocanescens, C. mussivus and C. odorifer have not been recorded in Ireland outside the Burren region (Muskett and Malone, 1980). Scots pine woodland disappeared from the Burren at least 2,500 years ago and much earlier in the rest of Ireland. Is it possible that these Dryas fungi are remnants of a long-extinct pine forest mycota? Survival of a relict forest mycobiota in a secondary plant community has been observed elsewhere albeit on a shorter time scale, for example in the secondary Arctostaphylos uva-ursi community of cleared Douglas fir forest in the Pacific Northwest (Molina and Trappe, 1982). Similarly, Watling (1981) has observed that Salix repens communities on former woodland areas in Scotland support many woodland fungi. However if the Burren mycota (or at least the woodland component) is a remnant, it is rather surprising that some genera such as Russula and Inocybe do not appear to be represented at all, even though both form mycorrhizas on Dryas and are well represented in calcareous pine woods.
aggressive mycorrhiza-
Table 1 Species Cantherellus aurora Boletus luridus Cortinarius odorifer Collybia dryophila Cortinarius calochrous Cortinarius infractus Cortinarius brunneus Cortinarius caesiocanescens Cortinarius lepidopus Stropharia semiglobata Entoloma serrulatum Cortinarius cinnamomeobadius Entoloma sericeum Mycena pura Cortinarius mussivus
%* 43.5 9.1 9.0 4.4 3.5 3.1 3.0 2.3 2.3 2.1 1.9 1.5 1.4 1.1 0.9
*% of total sporocarp biomass over 3 years sampling
Thirteen fungi have been shown from DNA and morphological evidence to be mycorrhizal on Dryas in the Burren. Fourteen other mycorrhizal morphotypes found on Dryas roots have not yet been positively identified as mycorrhizas of any member of the "sporocarp community". Mycorrhizas of some common species such as Boletus luridus and Cortinarius spilomeus have not been positively identified on Dryas at all and it is possible that these are mycorrhizal on other hosts, for example Helianthemum canum or Arctostaphylos uva-ursi, both of which have a much more restricted distribution in the Burren than Dryas. The diversity of fungi in the Burren, the grassland saprotrophs and Entoloma in particular, has tended to fluctuate greatly between years and with location. On higher ground where the soils are very shallow and organic, Dryas is abundant, and the woodland saprotrophs and mycorrhizal fungi are predominant. Lower areas have soils with a higher mineral content and support a grassy vegetation with less Dryas and a greater diversity of grassland saprotrophs. Discussion The most unusual feature of the Dryas-heath 32
Field Mycology Volume 2(1), January 2001 Malençon, G. & Bertault, R. (1970). Flore des Champignons Supérieurs du Maroc.Tome 1. Rabat. Molina, R. & Trappe, J.M. (1982). Lack of mycorrhizal specificity by the ericaceous hosts Arbutus menziesii and Arctostaphylos uva-ursi. New Phytologist 90, 495-509. Muskett, A.E. & Malone, J.P. (1980). Catalogue of Irish fungi-II Hymenomycetes. Proceedings of the Royal Irish Academy 80(B), 197-276. Watling. R, (1981). Relationships between macromycetes and the development of higher plant communities. In: The Fungal Community. Its Organization and Role in the Ecosystem.Wicklow, D.T. & Carroll, G.C. (eds). NY.
Acknowledgements I wish to thank Tor Erik Brandrud, Roy Watling, Hubert Fuller and David Mitchel for their help and advice. References Brandrud, T.E., Lindström, H., Marklund, H., Melot, J. & Muskos, S. (1990, 1992). Cortinarius, Flora Photographica. Vol. 1 and 2. Cortinarius HB, Matfors, Sweden. Harrington,T. (1996). Observations on the macrofungi of Dryas communities in the Burren, western Ireland. Irish Naturalists Journal 24(10), 413-414. Kühner, R. & Lamoure, D. (1986). Catalogue des Agaricales (Basidiomycetes) de la zone alpine du parc national de la Vanoise et des régions limitrophes. Travaux Scientifique du Parc National de laVanoise. 15, 103-187.
[Editor’s note: The photograph labelled Cortinarius odorifer in Notes and Records in the last issue of FM on page 135 is almost certainly C. dionysae, another species with a strong odour but of meal instead of anise. It differs also in its blue tints in the stem and duller ochre colours in cap and stem base. C. dionysae was also recorded on the recent Fermanagh foray in Northern Ireland.]
The dramatic landscape of the Burren in Western Ireland, home to a unique assemblage of fungi growing in association with mountain avens (Dryas octopetala). Photograph © T. Harrington.
33