Hawaii tropical dry forests

Bioimages home (click on an image to enlarge)
view this page in its intended navigation context

Hawaii tropical dry forests (WWF ecoregion OC0202)

O'hia lehua (Metrosideros) forest, north slope of Mauna Loa, island of Hawaii (c) 2005 Carol and Steve Baskauf

Source of bioregions data: Olson, D. M. and E. Dinerstein. The Global 200: Priority ecoregions for global conservation. (PDF file) Annals of the Missouri Botanical Garden 89:125-126.

Distinctiveness (1=highest,4=lowest): 1 (globally outstanding)
Dry forests harbor a number of specialist and endemic plant species.*

Conservation Status (1=most endangered, 5=most intact): 1 (critical)
10% of Hawaiian dry forests remain. Development, conversion to agriculture and pasture and burning continues to reduce the remaining habitat. Introduced plant species, rats, and grazing by livestock and feral mammals degrade existing habitats.*

Characteristic species*

Metrosideros spp. (O'hia lehua)
Acacia koa (koa)
and other genera

Some views from the ecoregion

Primary succession on lava flows, island of Hawaii

(l) Lava from Pu'u 'O'o eruption entering the sea, Chain of Craters Road, Hawaii Volcanoes Ntl. Park. More images from this eruption (r) Pahoehoe (smooth) and a'a (rough) lava, Hawaii Volcanoes Ntl. Park (c) 2005 Carol and Steve Baskauf hires hires

(l) O'hia lehua (Metrosideros) trees are important successional pioneers on lava flows, Hawaii Volcanoes Ntl. Park (r) Due to this, O'hia trees are often found in uniform-aged stands. North slope of Mauna Loa, island of Hawaii (c) 2005 Carol and Steve Baskauf hires hires

Manuka State Park, island of Hawaii

Parts of the mixed dry forest of Manuka are relatively intact. However, the native flora has been negatively impacted by destructive grazing by feral goats and pigs as well as invasive plant species. (c) 2005 Carol and Steve Baskauf hires hires

In this pit formed from a collapsed volcanic structure, the steep walls have prevented damage from introduced feral animals. Endemic plants cling to survival there. (c) 2005 Carol and Steve Baskauf hires

kipuka,off Pu'u O'o Volcano Trail, Saddle Road, island of Hawaii

A kipuka is an intact patch of forest that was surrounded by a lava flow. (l) From a distance on the lava flow, the trees look relatively short. (r) However, after descending the steep sides of the kipuka, one realizes that only the treetops were visable from outside and that tall trees are present there. (c) 2005 Carol and Steve Baskauf hires hires

This particular kipuka was surrounded by a lava flow in the 1800's. Therefore it has been isolated from other vegetation for over 100 years. Because of their isolation, kipukas may have relatively few invasive plants and are strongholds for native plant and bird species. (l) canopy (r) lichens on tree branch (c) 2005 Carol and Steve Baskauf hires hires

* Ricketts, T.H., E. Dinerstein, D.M. Olson, C.J. Loucks, et al. (1999) Terrestrial Ecoregions of North America: A Conservation Assessment. World Wildlife Fund - United States and Canada. Island Press, Washington, D.C. pp. 337-340.