These ecosystems are so distinctive that the Hawaiian Islands constitute a unique global bioregion. These ecosystems range from tropical dry forest, to subalpine grasslands, snowy alpine deserts, to brackish anchialine pools, subterranean lava tube systems with eyeless creatures, to windswept coastal dunes. All told, perhaps half of the 150 ecosystem types are considered in trouble, imperilled by human-related changes in the landscape. Most of the loss has occurred along the coasts and in the lowlands, where the majority of human habitation exists today. The Lyon Arboretum plant sale almost always includes native plants, as does the Foster Garden plant sale.
Many nurseries stock the hardier native plants, such as coastal akia, 'ohi'a saplings, 'ilima, etc.
Some of these nurseries have quite a variety. Another thing to avoid is pulling up native plants from the wild, or growing species that are rare or endangered. These require permits from government agencies to ensure that they weren't harvested from wild populations on the brink of extinction. Leave the growing of rare native plants to specialists, who are working hard to find the best growing conditions and methods for propagation, so that they can be replanted in the wild, and eventually available for our yards. Hawaii's endangered birds are generally upland birds, because many of them are susceptible to diseases such as bird malaria, which are spread by mosquitos at lower elevations.