Nu’alolo Kai, a wilderness area on the north shore of Kaua’i island on the Na Pali Coast, preserves one of the islands’ richest archaeological and paleobotanical sites dated between ca. AD 1300 and 1900. The State Parks Nu’alolo Kai Archaeological Resource Management Project, including the Na Pali Coast Ohana volunteers and UH students, was initiated in 1996 to protect these valuable historical natural and cultural resources. They have been mapping and documenting the existing Hawaiian sites, clearing them of vegetation and removing invasive plants. Recently palaeoecologists joined the common effort to restore the cultural landscape which existed in prehistoric times. One of the main objectives was to provide a baseline for a strategy to re-establish and revegetate the site with native and Polynesian-introduced plants. Archaeobotanical remains, including wood charcoal, seeds, cordage and other plant material were analysed to detect and evaluate long-term human-plant environmental interaction and landscape change. A flotation technique, followed by sorting various organic material from light and heavy fractions, was used to recover macroremains.

Results/Conclusions

Sixty-two vascular plant taxa were identified from the archaeobotanical assemblage; all were native or Polynesian except the invasive grass Eleusine indica. Many of them, including hala (Pandanus tectorius), pili grass (Heteropogon contortus), ‘ahu’awa (Mariscus javanicus), niu (Cocos nucifera), noni (Morinda citrifolia), kukui (Aleurites moluccana), hau (Hibiscus tiliaceus), awa (Piper methysticum), ipu (Lagenaria siceraria) and kou (Cordia subcordata) were also found in previously studied archaeological material from Nu’alolo Kai. However, only one quarter of the recovered plants from our study have been collected or observed at this site in modern times: in 1965 by St. John and in 2002 and 2006 by the botanical survey teams. According to this comparison, the trees and shrubs which have been most persistent around Nu’alolo Kai from the prehistoric period until now are ti (Cordyline fruticosa), taro (Colocasia esculenta), niu, naio (Myoporum sandwicense) and ‘aheahea (Chenopodium oahuense). The data further show that a number of taxa including naenae (Dubautia sp.), pukiawe (Leptecophylla tameiameiae), kukui, ‘akoko (Chamaesyce sp.), kopiko (Psychotria sp.), aiea (Nothocestrum sp.), aulu (Sapindus oahuensis) and hame (Antidesma plathyphyllum) are not present in the area today. The archaeobotanical findings suggest replanting these native and Polynesian-introduced species during a long-term restoration period. However, disturbance issues such as adverse human impact and a large feral goat population have to be taken into account.