Gardner Island
Page 5
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Transcription
areas are overgrown with Scaevola. Laxton (1951) mentions the large numbers of coconut crabs found by the early planters of the 1880's in spite of the fact that the Cocos grove was very limited. These animals appear to be characteristic of islands which do not support Cocos groves (e.g., Birnie) as well as those islands with small stands. Laxton (1951) states that the southeastern island rim has buka trees "reaching no great size" and that at the eastern tip "buka trees rise here sixty feet". No trees of this height were seen in 1964 but dry scattered Pisonia could be seen along the narrow rim on the southeastern side. Cordia is also reported from the eastern tip but this was not verified due to the briefness of our visit. Gardner Island is characterized by four major plant associations: Cocos, Scaevola - Tournefortia, Pisonia and Lepturus - Sida. The latter three cover the largest portion of the land area. The Pisonia groves are found on the interior mesic sites. In places such as the northwest hook where the land is wide, the Pisonia forms a closed canopy forest of now limited extent. Along the narrower northeast rim the trees are scattered and dry. The Scaevola - Tournefortia forms a fringing vegetation on the north and south sides. The Sida - Lepturus is found on gravel over coralline hardpan in open areas on the north and south sides. Lepturus is often found in pure stands at the edge of the lagoon or scattered under Pisonia trees. It is also common in beach sand near the fringe of Scaevola - Tournefortia. On the north side the latter association forms an open thicketed area almost impenetrable on the seaward side but less thick toward the lagoon. Under some of the Pisonia trees a considerable amount of humus and litter has accumulated over the coral rubble which forms the parent material for soil building. These trees are usually found at the top of a ridge of coral rubble. On the outside there is beach sand and on the inside a slope of coral rubble over coralline hardpan. This hardpan usually extends to the lagoon edge and appears to be .3 m. above the water at high tide. Unlike Hull Island, the north side of Gardner is unbroken by channels which connect the inner lagoon to the sea. Small pools on the east end indicate that at one time a channel probably existed at that end of the island. Digitaria was found naturalized on the north side and Ipomoea tuba was found rooted in coralline hardpan and coral rubble along with Fleurya ruderalis and Portulaca lutea. Among the introductions during the colonization of the island were: Pandanus sp., probably one or more of the scores of cultivars of Pandanus tectorius which have been developed in the Gilbert Islands (see Luomala, 1953); Digitaria pacifica, a grass which is of common intro- duction in the Line and Phoenix Islands; Eragrostis tenella, a common weed grass; Crinum asiaticum, an ornamental; Portulaca samoensis; Portulaca oleracea; Euphorbia cyathophora, an ornamental; Euphorbia thymifolia; Pedilanthus tithymaloides, an ornamental; Phyllanthus amarus; Terminalia catappa and Nicotiana tabacum. Morinda citrifolia was present on the island at the time of Maude's visit in 1937 (Maude, 1952). It is probably an earlier introduction but it is difficult to pinpoint. The most likely possibility was the early copra operation when Cocos were planted since there seems to be no record of a permanent settlement shipping copra. The papaya (Carica papaya) is naturalizing a few local areas in the abandoned village under