Reproductive Ecology and Population Genetics of Hawaiian Wiliwili, Erythrina sandwicensis (Fabaceae).

Abstract

Hawaiian dry forests are severely endangered with little habitat remaining and many threatened or endangered species. Wiliwili, or Erythrina sandwicensis (Fabaceae), is among the most iconic dry forest trees. This research focuses on the reproductive ecology, population genetics, and regeneration of wiliwili by addressing: 1) Who are the current flower visitors? 2) What is the effect of different pollination treatments on the number, size, and viability of wiliwili seeds and seedlings? 3) What is the genetic relationship among wiliwili populations? and 4) What is the regeneration status of populations on O‘ahu and Hawaiʻi islands? I found that all floral visitors were non-native species. Outcrossed pollination treatments produced significantly more fruit and seeds than any other treatment. Few seedlings and saplings were found in any population, and populations were genetically distinct across islands. Outplanting efforts can increase recruitment by enhancing the potential for outcrossing and increasing the number of seedlings and saplings.