Mauna Kea

Intro

Physical Resources

Mauna Kea stands approximately 13796 ft (4205.02 m), or 33000 ft (10058.4 m) from the ocean floor. Three cinder cones (pu`u) make up the summit of Mauna Kea (Pu`u Hau`oki, Pu`u Wēkiu, Pu`u Haukea), collectively referred to as Pu`u o Kūkahau`ula. Mauna Kea is the highest point in the Pacific Basin and the highest island-mountain in the world. Mauna Kea was listed as a National Natural Landmark in 1972. There is also evidence of glaciers that covered nearly 27-square miles of the summit region during the Pleistocene Epoch (Ice Ages) approximately 18,000 years ago.

Geology

Magma pushed up through the oceanic crust began building Mauna Kea approximately 750,000 years ago. Throughout its building stages, lava flowed from three main rift zones, forming a volcano resembling a warrior's shield. At the end of the shield stage eruptions became more explosive, discharging magma referred to as tephra. These eruptions created the numerous cinder cones dotted across the highest elevations of Mauna Kea.

During the Pleistocene Epoch (Ice Ages) the summit region of Mauna Kea, was covered with glaciers. It is believed that melting of the glaciers was the first source of water for Lake Waiau.

Climate

Above 7000 ft (2100 m), the upper slopes and summit region of Mauna Kea are classified as high alpine desert, above the trade wind inversion, where the air is dry and cool. During winter months (November-April) low-pressure systems tend to inhibit formation of the inversion layer, permitting increased precipitation, including snowfall at the summit. Annual precipitation ranges from 7-18 inches (18-46 cm) in the summit area to 12-20 inches (30-51 cm) at Hale Pōhaku.

Flora and Fauna

Mauna Kea can generally be divided into two ecosystems; the subalpine ecosystem, which is at 5600 ft (1700 m) to 9500 ft (2900 m), and the alpine ecosystem, which is occurs above 9500 ft (2900 m). Hale Pōhaku occurs in the upper reaches of the subalpine ecosystem, while the Mauna Kea Science Reserve occurs in the alpine ecosystem.

Subalpine Flora and Fauna (Hale Pōhaku and Access Road)

The subalpine pant life consists of māmane forests and understory plants including; alpine hairgrass, pili uka, `āheahea, pūkiawe, nohoanu, kalamoho, `iwa`iwa, olali`i, littleleaf stenogyne, and mā`ohi`ohi. Hawai`i catchfly, a threatened species under the Endangered Species Act (ESA), has been observed there as well. Invasive weeds such as grasses and common mullein also inhabit the area and appear to be increasing in abundance.

Māmane forests once ranged from sea level on the leeward side of Mauna Kea up to the tree line, however they have been pushed back, and greatly decreased due to habitat alteration, and invasive plant and animal species that inhibit the growth of Māmane trees.

The subalpine animal life consists of a wide variety of native arthropods (insects, spiders), palila, `amakihi, `apapane, `elepaio, `kiapola`au, `i`iwi, as well as many species of non-native birds and mammals (e.g. cats, rats, barn owls, and mongoose).

Alpine Flora and Fauna (Mauna Kea Science Reserve)

Alpine plant and animal communities on Mauna Kea begin just above the treeline, at approximately 9500 ft (2895.6 m), and rise to the summit of the mountain at 13796 ft (4205.02 m). The alpine communities can be divided in shrublands, grasslands, and desert, though they all can be described as barren, and no clear line exists between any of the groups.

Alpine Shrublands and Grasslands

Alpine shrublands are inhabited mainly by pūkiawe, ōhelo, Mauna Kea dubautia, Hawaiian bentgrass, pili uka, Douglas' bladderfern, kalamoho, `olali`i, `iwa`iwa. Now rare, historically common species included `āhinahina (Mauna Kea Silversword), lava dubautia, `ōhelo papa (Hawaiian strawberry), `ena `ena, nohoanu and alpine tetramolopium. Non-Native invasive species include hairy cat's ear, sheep sorrel, common mullein, and fireweed.

Relatively few animals have been documented to frequent this region.

Mauna Kea Summit – Alpine Stone Desert

The plant community at the summit consists of mosses, lichens, and algae, and a limited number of vascular plants, predominantly the same species found in the alpine shrublands and grasslands.

Lichens and mosses have the most diversity of any of the plant life found at the summit. A survey of the summit found 21 species of lichens, plus five possible others. Around half of the lichen species found on Mauna Kea are endemic (found only in Hawai`i), two of which (Pseudephebe pubescens and Umbilicaria pacifica) are limited to Mauna Kea alone. Mosses occur where water availability is more consistent, such as under overhanging rocks and in shaded crevices or caves where snow melts slowly. A survey identified approximately 12 species most of which are indigenous to the Hawaiian Islands.

The animal community at the summit consists almost completely of arthropods. The arthropod community on the summit is highly unusual in that it is mostly made up of predators and scavengers, and there are very few species that rely on plants as their sole food source. Surveys conclude that 21 resident species, and 14 species of undetermined origin have been observed in this region.