Saccharzm spontaneum at the bottom of Avalanche Valley. Other species are infrequent but include Imperata cylindrica, Pennisetum macrostachyum Trin., cf. Scleria sp., Scaevola novoguineensis K. Sch. 3338, Vitacea 3337 and several ferns. The community occurs on sites covered by ash from 30 cm. to over 14 m. in depth. The Euroschinus papuanus associes grows in the more favourable sites within
the blast area where only part of the topsoil has been removed, or where the topsoil is intact and the ash cover is less than 15 cm. deep. The community is a woodland 6-12 m. in height with Euroschinus papuanus Merr. and Perry predominating. A few other tree species were i'ecorded from this community. These are Ficus pungens Bl., Ficus sp., 'mumbura' (Or),Ficus sp., 'topu' (Or),Octomeles sumatrana Miq., Homalanthus sp., 'ugaho' (Or) and Albizia falcata (L.) Backer. The ground layer is fairly dense and consists of Saccharum spontaneum, Imperata cylindrica, ferns, Compositae and Orchidaceae. The transition between these two associes is of common occurrence occurring at sites covered by ash from 10-35 cm. in depth. The community consists of a dense stand of Saccharum spontaneum with scattered trees common in the Euroschinus papuanus associes.
SOLOMON S C A
Fig. 1. Map of the north-east portion of Papua showing the position of the volcanoes.
The Euroschinus papuanus - Musa spp. associes is somewhat lower in height than the Euroschinus papuanus associes and occupies sites where most of the topsoil has been removed by erosion. The community is dominated by species of,Musaceae, 'hura' and 'hubibi' (Or), together with tree species of the Euroschinus papuanus associes.