Silversword and lobeliad reintroduction linked to landscape restoration on Mauna Loa and Kīlauea, and its implications for plant adaptive radiation in Hawaiʻi

The endemic Hawaiian silversword and lobeliad lineages are two of the world's premier examples of plant adaptive radiation. The lineages also exemplify the severity of the threats confronting the Hawaiian flora, especially the threats posed by alien species. We have implemented collaborative reintroduction efforts with the endangered Kaʻū silversword (Argyroxiphium kauense) and Pele lobeliad (Clermontia peleana) in Hawaiʻi Volcanoes National Park. The efforts with the Kaʻū silversword have involved rediscovery, helicopter assisted rescue of diminutive remnant founders, managed breeding, and outplanting at two sites in the Park of > 21,000 seedlings deriving from 169 founders. Facilitated and natural achene dispersal following significant flowering at the two sites has resulted in the establishment of > 3400 seedlings as of summer 2016. The efforts with the Pele lobeliad have involved rediscovery, air-layering of remnant founders, managed breeding, and outplanting at two sites in the Park of > 1000 seedlings deriving from six of the seven known founders, with the first flowering at one of the sites occurring in summer 2016. We have linked the reintroduction efforts to landscape restoration at large scales in the Park and in adjacent State and private lands, thereby increasing the opportunities for substantial population growth and expansion of the Kaʻū silversword and Pele lobeliad in the future. Additionally, we have extended the reintroduction efforts, including the link to landscape restoration, to encompass all other endangered silversword and lobeliad taxa occurring historically on the eastern slopes of Mauna Loa or on Kīlauea.