Hawaiian Invasion


               Hawaii represents a very small percent of total U.S. landmass, but it also comprises 25% of the endangered species listed by the U.S. Fish and Wildlife Service.  Since Hawaii is one of the biodiversity hotspots on the planet while also being characterized as the most isolated mountainous archipelago on earth, it is also extremely vulnerable to invasive species by global trade and other sources.  Over 90% of Hawaii’s native plants aren’t found anywhere else on earth, and the endemism continues separately between the various high islands, so Kauai may have native species completely different from Maui.
               One of the highest priority invasive species for The Nature Conservancy on the Hawaiian islands of Maui and Kauai is the toilet-brush plant, also known as Himalayan Ginger.  This plant is seed-dispersed by birds and forms monotypic stands in undisturbed, intact native forests.  After this plant begins to take over the ground-layer of the forest, it limits growth of native canopy shrubs and trees.  Toilet-brush plant also displaces important ground layers such as diverse ferns or mosses that aid with slow-water release into the watershed.  This invasive does not allow for slow-water release, so it increases runoff and contributes to erosion through slippage.  Ultimately, this plant could have irretraceable impact on watershed quality and Hawaii’s remaining biodiversity.