In a museum at the 1835 plantation settlement of Koloa on Kauai, there's a placard that proclaims:
Maybe because the first place we visited on the island, the McBryde Garden, a unit of the National Tropical Botanical Garden, is a display of plants brought to Hawaii from away, I became very conscious that just about everything in this place comes from elsewhere -- even, long ago, the ancestors of the native Hawaiians who are thought to be descended from Polynesian and perhaps Tahitian voyagers.
Apparently there were only about 12 genuinely native plant species -- nearly every bit of greenery on the islands was brought for somewhere else. So were most of the birds and all the larger animals. Now all these living things co-exist -- or more accurately jockey for niches to live in.
Perhaps the relative newcomer status of so many life forms leads to the prominence of the many warnings about how to deal with various invasive species. Rules are essential.
That last sign is about a rare native, struggling against extinction by vehicular competitors.
Of course the truly disruptive invasive species is not usually named on these warnings: the human tourist. When rice and sugar cane cultivation collapsed on Kauai, the island's already heterogeneous population was left to sell the island's beauties and breezes to wave after wave of vacationers and curiosity seekers. That influx certainly tests the equilibrium between the values of past heritage and of progress. As far as I can see, to date Kauai is managing the delicate dance both practically and gracefully.