FALLA: BIRDS AND l\1AMMALS 63 General
The luxuriant growth of O. lyallii, and the large numbers of young plants, with germination even in cracks in the bark of prostrate trunks, have often been noted-for instance by Cockayne (1904) and Dorrien-Smith (1908). Although Cockayne could see no reason why it "should not be the dominant fo...
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.377.8327 http://www.nzes.org.nz/nzje/free_issues/ProNZES12_63.pdf |
| Summary: | The luxuriant growth of O. lyallii, and the large numbers of young plants, with germination even in cracks in the bark of prostrate trunks, have often been noted-for instance by Cockayne (1904) and Dorrien-Smith (1908). Although Cockayne could see no reason why it "should not be the dominant forest of the Southern Islands", O. lyallii has always been considered as fighting a losing battle in the Auckland Islands. To Dorrien-Smith (1908) it was swamped out by rata, "hence its disappearance from the main islands"; to Cockayne (1904) it was perhaps a relic of a former primeval forest, "ousted by a new formation as the conditions changed"; and he also considered "that the tree in question may have been a member of the now vanished and problematical forest of an ancient Antarctic continent " (Cockayne 1907; d. also 1928: 174). I suggest that O. lyallii is in fact increasing its area on the Auckland Islands, and that the present populations are derived from a relatively recent immigration, probably in the early 19th century, with Ewing 1. as the point of entry. From here, it is suggested, the species moved east to points around Ross Harbour, and soutbwards along the coast (Fig. 5). The source of O. lyallii would probably be the Snares, the only other locality where it is usually recognised as occurring. But when speculating on the history of this species it should be recalled that specimens from Milford Sound (Hooker 1867) and from Stewart Island and the Bluff (Cockayne 1927, 1928) have been considered similar to or identical with O. lyallii. As Moar (1958 a) mentions the difficulty of distinguishing O. lyallii pollen from that of the Pleurophyllums, particularly P. hookeri, pollen analysis may not be fruitful in elucidating the history of this noble composite in the Auckland Islands. ACKNOWLEDGEMENTS I am very grateful to Dr. R. A. Falla for a vegetation map of Ewing Island on which Fig. 4 is based and for his interest in these problems; and to Mr. K. R. West for preparing the illustrations. |
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