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Notes on the Lichens of Goat Island, Niagara
Falls http://www.mobot.org/plantscience/ResBot/index.htm Republished from Clintonia: Magazine of the Niagara
Frontier Botanical Society 4(1): 1-1. 1989. |
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NOTES
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. |
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