Kahanahāiki

Koa leaves & flowers

Hiking in to Kahanahāiki

KahanahāikiLocation: Northern Wai‘anae Mountains

Land Owner: U.S. Army Garrison, Hawai‘i

Land Manager: O‘ahu Army Natural Resources Program (OANRP)

Acreage: 104 acres (Subunits I and II)

Elevation Range: 1,400 ft - 2,300 ft

Description: Kahanahāiki Management Unit (MU) is located in the Mākua Military Reservation (MMR) and is accessed via the Mokulē‘ia Forest Reserve. It is on the eastern border of Mākua, at the eastern end of the valley. The Subunit I portion of the MU is currently fenced, and extends from a high point at the top of “C-Ridge” (the ridge that divides Mākua into its two valleys) to the north and east. From C-Ridge, it extends north in a gentle slope that divides into two shallow gulches. These gulches converge at a cliff zone. North of the cliff area, it encompasses one large gulch and the ridges bordering it. This gulch runs north, and then curves to the west. A large cliff/waterfall marks the north boundary of Subunit I. Overall, the north and east aspects are relatively native while the south and west exposures are dominated by weeds. Subunit II is bordered by Subunit I on the east, and stretches across several ridges and gulches running west towards the floor of Mākua valley. Plans to construct a fence surrounding Subunit II are slated for 2013.

Native Vegetation Types: Mesic mixed forestCanopy: includes Acacia koa, Metrosideros polymorpha, Nestegis sandwicensis, Diospyros

spp., Pouteria sandwicensis, Charpentiera spp., Pisonia spp., Psychotria spp., Antidesma platyphyllum, Bobea spp. and Santalum freycinetianum.

Understory: includes Alyxia oliviformis, Bidens torta, Coprosma spp., and Microlepia strigosa

Management History: Much effort has been focused on the Kahanahāiki MU over the years. It is home to many rare taxa, including plants, snails and birds. Since the area is diverse,

‘Ōhi‘a lehua

easily accessible, and relatively small, many field techniques were first tested and installed here by OANRP staff. These include the first large fence, first snail enclosure, first rat trap grid, first common native plant reintroduction, and lots of experimentation with weed control. Techniques developed at Kahanahāiki are used at all other MUs. Volunteers often visit and have dedicated countless hours caring for resources as well as learning about the importance of native forests from OANRP staff.

Timeline of important events:

• 1995: OANRP begins management at Kahanahāiki. Surveys are conducted. Staff becomes familiar with MU.

• 1996: MU fence construction for Subunit I completed.• 1998: Pigs eradicated from the Subunit I fence.• 1998: Snail enclosure built around the core portion of the A. mustelina population.• 1999-2009: Pig pressure on the

fence was reduced by control efforts conducted outside of the fence.

• 1999-2009: Restoration work occurs across the MU focusing on most pristine areas. Work includes weed removal, and re-vegetation with common and rare species.

• 1998-2009: Rodent control through the use of bait stations with rodenticide and snap traps for the protection of A. mustelina and ‘Elepaio.

• 2009: OANRP begins rodent control over the entire MU with a “Trap Out” grid (a grid of several hundred snap traps covering Kahanahāiki).

‘Ōhi‘a lehua & koa.

Kāhuli tree snail under a Lama leaf

Rare Plants:Alectryon macrococcus var. macrococcus, endangeredAlphitonia ponderosa, endangeredBobea sandwicensis, endangered Cenchrus agrimonioides var. agrimonioides, endangeredCyanea superba subsp. superba, Hāhā, endangeredCyrtandra dentata, Ha‘iwale, endangered Delissea waianaeensis, Hāhā, endangered Diellia falcata, endangeredEuphorbia haeleeleana, endangered Flueggea neowawraea, Mēhamehame, endangered Hedyotis degeneri var. degeneri, endangeredLepidium arbuscula, endangered Nototrichium humile, endangered Pteralyxia macrocarpa, Kaulu, species of concern Schiedea nuttallii, endangered Schiedea obovata, endangered

Rare Animals:Achatinella mustelina, Kāhuli, tree snail, endangered Chasiempis ibidis, O‘ahu ‘Elepaio, flycatcher bird,state endangered (historical home ̶ no birds sited for several years in Kahanahāiki ̶ two pairs protected in adjacent Mākua Valley),

Threats to Rare Species:• Pigs - threaten all species• Rats - threaten all species• Predatory Snails - threaten A. mustelina• Slugs - threaten C. superba subsp. superba, S. obovata, S. nuttalii • Ants - threaten an unknown number/type of species• Weeds - threaten all species• Fire - threatens all species

Hāhā, Cyanea superba ssp. superba

Schiedea obovata, with fruit

Cenchrus agrimonioides

var. agrimonioides,immature fruit

Other Native Plants:‘A‘ali‘i, Dodonaea viscose‘Akia, Wikstroemia spp. ‘Akoko, Chamaesyce multiformis‘Āla‘a, Āulu, Pouteria sandwicensisAlahe‘e, Psydrax odorata Āulu, Lonomea, Sapindus oahuensisBracken fern, Pteridium aquilinum Carex sedge (thick-leaved), Carex wahuensisCarex sedge (thin-leaved), Carex meyenii Hulumoa, Korthalsella spp. ‘Ie‘ie, Freycinetia arborea‘Iliahi, Santalum freycinetianumKauila, Alphitonia ponderosaKoa, Acacia koaKoki‘o ke‘oke‘o, Hibiscus arnottianus Kōlea, Myrsine lessertianaKo‘oko‘olau, Bidens torta Kōpiko, Psychotria marinianaLama, Diospyros hillebrandii & D. sandwicensis Maile, Alyxia oliviformisMāmaki, Pipterus albidus Manono, Kadua affinis (formerly Hedyotis terminalis) Maua, A‘e, Xylosma hawaiienseMoa, Psilotum nudum Naupaka kuahiwi, Scaevola gaudichaudiana‘Ohe, Reynoldsia sandwicensis

Koa butterfly

‘Ūmi‘i ‘Akoko

Koki‘o ke‘oke‘o Kamehameha caterpillar Ko‘oko‘olau

‘Ohe mauka, Tetraplasandra oahuensis‘Ōhelo, Vaccinium spp.‘Ōhi‘a, Metrosideros polymorphaOlopua, Pua, Nestegis sandwicensis Pala, Marattia douglasii (fern)Pala‘ā, Sphenomeris chinensis (fern)Palapalai, Microlepia strigosa (fern)Pāpala, Charpentiera spp.Pālapa kēpau, Pisonia spp.Pohuehue, Ipomea indica Pūkiawe, Styphelia tamiameiae‘Uki‘uki, Dianella sandwicensis‘Ūlei, Osteomeles anthyllidifoliaUluhe, Dicranopteris linearis (fern)

Other Native Animals: ‘Amakihi, honeycreeper bird, Hemignathus virens ssp. chloris‘Apapane, honeycreeper bird, Himatione sanguineaHappy-Face Spider, Theridion grallator Kamehameha butterfly, Vanessa tameamea Koa butterfly, Udara blackburnii Mū beetle, Rhyncogonus fordii Pinao, Anax strenuus (dragonfly),‘Ūmi‘i ‘Akoko, Dictyophorodelphax mirabilis & D. swezeyi (delphacid plant-hopper)

Pukiawe fruit

Palapalai