Notes on the Lichens of Goat Island, Niagara
Republished from Clintonia: Magazine of the Niagara
Frontier Botanical Society 4(1): 1-1. 1989.
ON THE LICHENS OF GOAT ISLAND,
by Richard C. Harris, New York Botanical Garden, Bronx, NY 10458-5126
[Text is as published in Clintonia, Magazine of the Niagara Frontier Botanical Society, Vol. 4(1): 1-2. 1989.]
As part of a botanical survey by Patricia Eckel of Goat Island and the adjoining Three Sisters and Luna islands, at Niagara Falls, New York, Bill Buck and I spent two days in November 1988 collecting the lichens. We are grateful to Ms Eckel for affording us the opportunity. A total of 187 collections yielded 56 species of lichens. The only other collections from Goat Island were made in 1870 and 1871 by George W. Clinton and Mary L. Wilson. They collected ten species of which only two are still present. A complete list of the lichens will be published elsewhere by Ms Eckel.
The status of the lichens on Goat Island today is rather enigmatic. My best guess is that the present expression of the flora results from the effects of pollution and destruction of the original vegetation offset by the buffering nature of the limestone rocks which are extensively exposed. The survivors are often not in the best condition and are frequently covered with foreign algae, which I interpret as a sign of too much shade. Foliose and fruticose species are not common, especially on trees. A startling exception is Phaeophyscia orbicularis (Necker) Moberg, which plasters most of the trees in the open, both native and recently planted introductions alike. This species is otherwise very rare in northern New York with the bulk of its United States distribution west of the Mississippi, and it is common in Europe. Phaeophyscia rubropulchra (Degel.) Moberg, which one would expect to be common, is represented by only a single collection. There are a couple possible explanations, differing tolerance to drought and pollution or some sort of founder effect whereby P. orbicularis got established first and now maintains dominance by a vast number of asexual propagules effectively excluding other Phaeophyscias.
On rock the situation is somewhat different as P. adiastola (Essl.) Essl. is also well represented but neither attains any extensive cover on this substrate. The normally weedy Parmelia sulcata Taylor was collected only twice and then only in very moist exposed habitats. Xanthoria fallax (Hepp) Arn., which often occurs with Phaeophyscia and Physcia, was also rare on exposed trees. Also odd, only a single Cladonia, C. humilis (With.) Laundon, was found and it was growing on wood, which is an unusual substrate for this species which usually occurs on clay soil in old fields. Two foliose species collected in the 1870's, Anaptychia setifera Raes. and Teloschistes chrysophthalmus (L.) Th. Fr., are recorded otherwise in New York only from Long Island, perhaps attesting to the originally very "oceanic" character of the immediate falls area. Both are now extinct in New York State. The majority of the lichens surviving grow directly on the lime rock, on or among mosses on rock or on rotting wood. They would perhaps be protected from pollution by the neutralizing effects of the lime or from drought by water retained by the rotting wood. The most common species on rock are Bacidia granosa (Tuck.) Zahlbr., Candelariella aurella (Hoffm.) Zahlbr., Endocarpon pusillum Hedwig, Lecanora dispersa (Pers.) Sommerf., Mycobilimbia sabuletorum (Schreber) Hafellner and Verrucaria muralis Ach. The Mycobilimbia is one of the two species collected in both the 1870's and 1980's. A variety of Caloplaca and Verrucaria species, some not yet identified, are also common. Lepraria finkii (B. de Lesd. in Hue) R. C. Harris, a pollution-tolerant species (it survives in Manhattan), is common on rock and tree bases. Buellia punctata (Hoffm.) Massal. is the only frequent bark crust. Another anomalous feature is that the genus Micarea is absent and its niche on rotten wood is occupied by several possibly undescribed species of Bacidia s. lat. Since most lichens require relatively high light and humidity levels, it is not surprising that Luna Island and the Three Sisters have the most diversity while the central woodland on Goat Island itself has the lowest. It may well be that the lichens of Goat Island have been mainly crustose since the 1870's as George Clinton notes on an herbarium packet including Caloplaca flavorubescens (Hudson) Laundon and Lecidea russula Ach. (neither found in 1988): "Took it, I suppose, partly because I was in despair, & partly because the tree was Ash," which I take to mean he was not finding many conspicuous lichens. I have no information on current pollution levels around Niagara Falls, but assuming they have dropped in recent years, lichen diversity could be maintained or perhaps increased by keeping open areas, especially on the Three Sisters, but turning some of the lawn into an old field situation, which would provide habitat for Cladonias, by reintroducing Thuja, which is a good substrate for many lichens, and by leaving more fallen trees.
I maintain a checklist of the lichens of New York State based on specimens seen. The only collection so far of Gyalecta jenensis (Batsch) Zahlbr. was made by Clinton on Goat Island in 1870. In our 1988 Goat Island collections, six species are additions to the State list: Arthonia lapadicola (Taylor) Branth & Rostrup, Bacidia epixanthoides (Nyl.) Lettau, Caloplaca cirrochroa (Ach.) Th. Fr., Lecania perproxima (Nyl.) Zahlbr., Leptogium juniperinum Tuck. and Pyrenocollema strontanensis (Swinscow) R. C. Harris.
Goat Island and its associated islands and, I presume, the entire Niagara Gorge are undoubtedly important refugia for a community of lichens very similar to those found in similar lime-rich areas of Ontario and Michigan. Although it is clear some of the members are already extinct in New York, I hope that measures will be taken to retain what is left.