Te Awatapu Forest.
Standing on the edge of the cliffs not far from the Trig station which marks the highest point on Chatham Island, one looks down upon a large piece of forest lying in a basin far below. This basin is formed from a great mass of the upper surface of the tableland, which, probably undermined by water, long ago fell into the sea below. In some places perpendicular cliffs, still devoid of vegetation, show whence this great mass of land must have fallen. In other places the cliffs are covered with a good deal of soil, in which is growing a luxuriant vegetation. This forest at the time of my visit was in its virgin condition. A few sheep certainly had just previously found their way down the steep cliffs, but their presence was not felt by the vegetation. Recently the forest, as mentioned in the introduction, has been opened up to stock by means of a cut track, so it seems very necessary to put on record its general appearance.
The ground of the forest consists of clay mixed with a certain proportion of peat, the clay being derived from that stratum which doubtless underlies all the tableland bogs. The surface, which as a whole slopes to the sea, from which it is separated by a jagged wall of rocks, is very uneven; the soil at the time of the landslip must have been heaped up in some places, and with corresponding hollows in others. This unevenness has also been accentuated by erosion. Through the centre of the forest a stream flows, which puts one in mind of some small New Zealand mountain torrent. This stream is fed by the never-failing supply of water from the bogs above, whence the main branch leaps down the precipitous cliffs as a waterfall.
The forest, as pointed out before, resembles in part the tableland and in part the lowland forest. It differs from the tableland forest in that it contains Plagianthus chathamicus, Piper excelsum, and Rhipogonum scandens, in large quantities; but, on the other hand, Dracophyllum arborium and Senecio huntii are plentiful. The presence of Coriaria ruscifolia, here quite a tree, also separates this formation
from that of the tableland. The undergrowth of ferns is greater than I observed elsewhere on the island. Polypodium rugulosum with fronds 1.5 m. in length, Aspidium oculatum of nearly equal size, and Lomaria procera with fronds rather larger than either of the above, form dense masses on the steep well-drained slopes. Asplenium bulbiferum was extremely proliferous; on one pinna were as many as fourteen young ferns, several of which were 3.2 cm. long. Some of such young ferns had fronds 8 cm. long, with sometimes three together. This proliferous habit of Asplenium bulbiferum seems evoked by excessive moisture in the atmosphere, for such ferns are met with only in the dampest forests; but this has not been established experimentally as yet. Tree ferns so tall as to reach into the tree-tops are, as in all Chatham Island forests, very abundant, and, as usual, their stems have a large plant population.
The most striking feature of the forest is the enormous number of the climbing stems of Rhipogonum scandens. These, together with the closely growing thin liane-like stems of Piper excelsum, made travelling through certain parts very laborious, one having actually in many cases to crawl along the ground for considerable distances.
Besides ferns, the floor of the forest is covered in many places with the thin-leaved Australinia pusilla, while seedlings of the different trees are very abundant. Within the forest there are two natural ponds, and one or most likely more open spaces. The ponds, though plainly visible from the summit of the cliffs, I unfortunately missed finding, owing to the density and difficulty of the “bush.”
The open space was covered with Polypodium rugulosum 1.4 m. tall, Carex ternaria(?), and Agrostis æmula, with Acæna novæ-zelandiæ climbing through the whole. Such an open space, taken in conjunction with the ponds and their surroundings, looks like a remnant of the original vegetation which first took possession of the ground after the landslip and prepared the way for forest trees. This view is supported by the fact that young trees of Plagianthus chathamicus are growing on the open space mentioned above, and that such a place consequently at no very distant date would, if not disturbed, become uniform with the rest of the forest.