Hawaiian tropical dry forests

Summary

Coordinates: 21°N 157°W / 21°N 157°W / 21; -157

The Hawaiian tropical dry forests are a tropical dry broadleaf forest ecoregion in the Hawaiian Islands. They cover an area of 6,600 km2 (2,500 sq mi) on the leeward side of the main islands and the summits of Niʻihau and Kahoʻolawe. These forests are either seasonal or sclerophyllous.[2] Annual rainfall is less than 127 cm (50 in) and may be as low as 25 cm (9.8 in);[4] the rainy season lasts from November to March.[5] Dominant tree species include koa (Acacia koa), koaiʻa (A. koaia), ʻakoko (Euphorbia spp.), ʻōhiʻa lehua (Metrosideros polymorpha), lonomea (Sapindus oahuensis), māmane (Sophora chrysophylla), loulu (Pritchardia spp.), lama (Diospyros sandwicensis), olopua (Nestegis sandwicensis), wiliwili (Erythrina sandwicensis), and ʻiliahi (Santalum spp.). Endemic plant species in the dry forests include hau heleʻula (Kokia cookei), uhiuhi (Caesalpinia kavaiensis), and Gouania spp. The palila (Loxioides bailleui), a Hawaiian honeycreeper, is restricted to this type of habitat.[2]

Hawaiian tropical dry forests
Starr 040220-0314 Santalum paniculatum.jpg
An ʻiliahi (Santalum paniculatum) at Hawaiʻi Volcanoes National Park.
Ecology
RealmOceanian
BiomeTropical and subtropical dry broadleaf forests
BordersHawaiian tropical low shrublands, Hawaiian tropical rainforests and Hawaiian tropical high shrublands[1]
Geography
Area6,600 km2 (2,500 sq mi)
CountryUnited States
StateHawaii
Conservation
Conservation statusCritical/Endangered[2]
Global 200Yes[3]

Prehistoric dry forestsEdit

The plant composition of Hawaii's dry forests has changed rather dramatically since the arrival of Polynesians, excluding the deliberate introduction of non-native species.[5] Fossilized pollen has shown that loulu (Pritchardia spp.) forests with an understory of Ka palupalu o Kanaloa (Kanaloa kahoolawensis) and ʻaʻaliʻi (Dodonaea viscosa) existed on the islands' leeward lowlands[6] from at least before 1210 B.C. until 1565 A.D. Populations of loulu and ʻaʻaliʻi still exist in diminished form, while only two Ka palupalu o Kanaloa specimens have ever been seen in the wild.[7]

MauiEdit

 
Auwahi Dryland Forest

The Auwahi Dryland Forest Restoration Project has produced a substantial forest on the slopes of Haleakala on the island of Maui.[8]

See alsoEdit

ReferencesEdit

  1. ^ "Hawaii Tropical Dry Forests". Bioimages. Vanderbilt University. Retrieved 2011-11-19.
  2. ^ a b c "Hawaii tropical dry forests". Terrestrial Ecoregions. World Wildlife Fund. Retrieved 2011-11-19.
  3. ^ Olson, David M.; Eric Dinerstein (2002). "The Global 200: Priority Ecoregions for Global Conservation" (PDF). Annals of the Missouri Botanical Garden. 89 (2): 199–224. doi:10.2307/3298564. JSTOR 3298564.
  4. ^ World Wildlife Fund, ed. (2001). "Hawaii tropical dry forests". WildWorld Ecoregion Profile. National Geographic Society. Archived from the original on 2010-03-08. Retrieved 2009-02-15.
  5. ^ a b "The Hawaiian Islands". Tropical Dry Forests of the Pacific. University of California, Los Angeles. Archived from the original on 2009-12-24. Retrieved 2009-02-15.
  6. ^ James, Helen F.; Johnathan P. Prince (May 2008). "Integration of palaeontological, historical, and geographical data on the extinction of koa-finches". Diversity & Distributions. 14 (3): 441–451. doi:10.1111/j.1472-4642.2007.00442.x. S2CID 40057425.
  7. ^ Bohm, Bruce A. "Rare Delights in Hawaiʻi". Floridata. Archived from the original on 2008-12-20. Retrieved 2009-02-15.
  8. ^ PARSONS, ROB (2007-04-12). "Maui Koa". Maui Time. Retrieved 2018-02-13.

External linksEdit

  • Medeiros, A. C.; C.F. Davenport; C.G. Chimera (1998). "Auwahi: Ethnobotany of a Hawaiian Dryland Forest" (PDF). Cooperative National Park Resources Studies Unit, University of Hawaiʻi at Mānoa. {{cite journal}}: Cite journal requires |journal= (help)