Composition of Certain Native Dry Forests: Mokuleia, Oahu, T.H.

Abstract

The richness in tree species of Hawaiian dry forests has attracted the attention of many botanists. Rock (1913) thought it possible to collect more species in dry forests in single day than in a week or two in the rainforests. Selling (1948) stated: More than half of the many species of trees in these islands belong to this dry He thought, however, that dry forests had mostly disappeared from Oahu, Kauai, Molokai, and West Maui, and that only scattered remnants remained elsewhere. The recent studies of Hosaka (1937) and Egler (1939, 1942, 1947) tended to support this view. Nevertheless, scattered references to botanical bananzas in remote areas of Oahu exist in the literature. Thus Judd (1931) reported: An interesting mine of 42 different species of Hawaiian trees was discovered in small gulch in Makua Valley, on Oahu. His mention of Mehamehame (Drypetes phyllanthoides (Rock) Sherff) and Kalamona (Cassia gaudichaudii Hook. & Arn.) trees leaves little doubt that he was dealing with dry forest. In the spring and summer of 1950 the writer accompanied Miss Amy Greenwell, of Captain Cook, Hawaii, and Mr. Otto Degener, of Waialua, Oahu, on several plant-collecting excursions in the Mokuleia region of Oahu, during which many forests rich in reputedly rare, dryland tree species were discovered. The purpose of this paper is to describe certain of these seasonal forests and to mention certain features of the autecology of the more noteworthy species, for it is my opinion that, in addition to the intrinsic interest of these plants, they may have considerable potential importance in the management of Hawaiian watersheds.