1972 - The Vasculum

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VASCULUM VOL. LVII. No. 3. 1972
have been represented in the occasional unshaded reaches of the chalk streams of south-east England, where now
it is almost certainly absent. Whether or not this was so its present distribution in Britain is decidedly restricted,
and the streams in Upper Teesdale still form one of the best examples of its development. Although the algae
cannot claim the glamour or quite the rarity of flowering plants like Gentiana verna. It is nevertheless hoped that
the remaining streams will be preserved for all time in something like their present form. While the aIgal
vegetation is unlikely to suffer much from collecting, trampling or any small climatic changes associated with the
reservoir, it might well suffer greatly from any change in land usage, such as any addition of fertilizers.
ACKNOWLEDGMENTS
The authors are most. grateful to. the following for helpful discussion: Dr. S. Golubic, Dr. E. Kann, Miss S. M.
Kirkby, Mr. T. Buffey. M.K.H. was supported by a grant allocated by the Teesdale Trust and financed by Imperial
Chemical Industries Ltd.
REFERENCES
Bradshaw, M. E. B., and Clark, W. A. (1965): 1 Flora and vegetation. In: Valentine, D. H. (Ed.) The Natural
History of Upper Teesdale, Pp, 23-42. Northumberland & Durham Naturalists' Trust Limited. 70pp.
Geitler, L. (1932): Cyanophyceae. L. Rabenhorst's Kryptogamen Flora XIV. Leipzig.
Holdgate, M. W. (1955): The vegetation of some springs and wet flushes on Tarn Moor, near Orton,
Westmorland. J. Ecol. 43; 80-89.
Holmes, T. N. H., Lloyd, E. J. H. Potts, M., and Whitton, B. A. (1972): Plants of the River Tyne. The Vasculum
Vol. LVlI: 56-78.
Johnson, G. A. L., Robinson, D., and Hornung, M. (1971): Unique bedrock and soils associated with the Teesdale
flora. Nature, Lond. 232: 453-456.
Pigott, C. D. (1956): The vegetation of Upper Teesdale in the North Pennines. J. Ecol. 44; 545-586.
Whitton, B. A. (1970): Toxicity of heavy metals of freshwater algae: A review. Phykos 9: 116-125.
THE DIATOMS OF SLAPESTONE SIKE, UPPER TEESDALE.
J. R. CARTER
Elm Bank, Denholm, Hawick
The diatoms examined in this contribution were all collected by Mr. A. Peabody and Dr. B. A.
Whitton, one collection being made on 19th April, 1970 and the other on 6th August, 1970. A complete analysis
has shown little if any significant distinction between the two gatherings, the species present being identical in the
main stream and any rather unusual forms being confined to small tributaries and flushes
The samples contain 108 identified species, and two or three which are either quite new or perhaps
inadequately described in the literature. These latter forms have, of necessity been omitted from discussion here
and will receive attention later. Taken from between forty and fifty stations from the headwaters of the Cow Green
reservoir, all kinds of habitats have been sampled and the results show some containing as many as 50 different
forms whilst one, a peaty drain, was completely devoid of diatoms. As one would expect the richest hauls came
from amongst mosses, Rivularia colonies, algal beds and from some of the adjacent vegetation like liverworts. All
these dwellers in the stream tend to act as filters to catch the diatoms and one cannot be sure that to find a form in
such