Natural Areas of Hawaii
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| Native trees of Auwahi, Maui | |||
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| Native trees of Auwahi, Maui | |||
| Auwahi is a remnant native dry forest on the south slope of East Maui. The noted Hawaiian botanist Joseph F. Rock singled out the Auwahi district on Haleakala, and the Pu’u-wa’awa’a district of the Big Island as the richest botanical regions in the Territory, with more tree species than any Hawaiian rain forest. Over the past centuries, this forest has been much degraded and now without action is threatened with total extirpation on Maui. Auwahi is a biological and ethnobotanical treasure. Of the 50-odd species of rare Hawaiian trees found here, 41 species had specific Hawaiian ethnobotanical uses, 19 as medicines, 13 in making specific tools, 13 in canoe construction, eight in kapa making, eight to make widely ranging dye colors, and at least seven of the trees have religious significance. Without our efforts, all of these trees, their uses, their associated animals will all perish forever. The Auwahi Restoration Group is a coalition of private and public agencies spearheaded by the U.S. Geological Survey and Ulupalakua Ranch. We are working on a historic effort at dryland forest restoration by planting and weeding exclosures in order to "jumpstart" this unique native forest. Please call Art Medeiros at 573-8989, e-mail auwahi@yahoo.com, or visit auwahi.org for more information or an update on the next Auwahi service trip. |
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The first attempts at conservation at Auwahi were made in the late 1960's, when retired Territorial Forester Collin Lennox and The Nature Conservancy constructed a large exclosure in an abortive restoration effort which unfortunately coincided with the invasion of the area by kikuyu grass (Pennisetum clandestinum). USGS scientists (with National Park Service until 1993) began exploratory work, with the permission (and blessing) of the landowner, Ulupalakua Ranch, 19 years ago. A status report based on extensive field exploration in the early 1980s (Medeiros et al. 1986) called attention to continued deterioration of native vegetation on leeward Haleakala and identified the Auwahi area as a prime area worthy of concerted conservation efforts.
Reasons for lack of reproduction may be complex and overlapping but probably include browsing by domestic cattle and digging by feral pigs; displacement by the aggressive introduced tropical African pasture grass, kikuyugrass, and microclimate change. Our observations suggest that with protection from ungulate browsing and digging, removal of the kikuyugrass mat, and restoration of favorable microhabitat, dryland forest restoration can be achieved at Auwahi.
The diverse forest continues to decline due to the absence of seedlings and saplings. For many species, reproduction by seed may not have occurred for a period of 50 to several hundred years. We have seen seedlings and saplings in the field for only 12 of 50 tree species at Auwahi over a 19-year period of field observations. Despite this, at least 36 species can be germinated and grown in greenhouse conditions. Of native trees found at Auwahi, six are listed by FWS as endangered species, five have been considered "species of concern," and many of the others are rare and declining range-wide.
Ethnobotanically, these forests were invaluable to early Hawaiians (Medeiros et al. 1999). Of the 50 tree species found here, 41 had specific uses. Nineteen species were used in medicines, 13 in making specific tools, 13 in canoe construction, eight in making bark cloth, eight to make dyes ranging from pink to blue to a rich yellow-orange. At least seven species have spiritual significance and were used in religious and cultural ceremonies. Other miscellaneous uses ranged from fire to bird lime, to a fish narcotizing agent. There s tremendous interest within both the Hawaiian community in restoring tracts of dryland forest. However, to date there are no major success stories for dryland forest restoration in Hawai'i.
Assisted by past funding from FWS, USGS his located one of the richest tracts of Auwahi for restoration, fenced a prime 10.4 acre site for experimental restoration (elevation 4,000 ft.), and has initiated a greenhouse propagation and outplanting program with assistance of funds provided directly to the landowner by FWS. We presented a conceptual plan for 120 acres of Auwahi restoration at the Hawaii Conservation Conference in July 1997 with landowner approval. The plan involves replacing the kikuyugrass cover among the museum- piece trees with a "nurse forest of quick-growing native trees to create relatively moist, semi-shaded microhabitat in which dryland forest seedlings can become established and flourish (Figure 2). A relatively brief window of opportunity exists during which this declining dryland forest is relatively restorable. Though forest decline is at a relatively advanced stage, excellent seed sources for most species still exist.
Currently, we are in the midst of implementing an experimental USGS-funded research project to develop methodology for establishing a nurse forest of native shrubs/trees to secure the site from weed invasion and eventually (within several years) provide habitat for restoration of 50 tree species. Based on the results of this project, the most effective methodology would be used as soon as funding for management could be obtained (from FWS and other sources) to restore dryland forest on additional Auwahi land, to which the landowner has willingly agreed. Based on methods developed through our ongoing pilot project, we can soon feel confident in our ability to cooperatively restore and manage dryland forest at Auwahi.
late 1800s
Lennox (1967) wrote, "In the last half of the century cattle raising as a ranching enterprise gained headway and undergrowth, particularly pukeawe and `a`ali`i, was destroyed by fire to make way for imported forage grasses. Natural reproduction came to an end for many species."
1887-1912
Hosmer (1912) writes of vegetation in adjacent Kula districts, "belt of heavy forest with dense undergrowth in the Kula districts between the elevations of 3500 and 5000 feet...Gradually opened up by grazing until now it has practically disappeared save as its former extents can still be traced by dead stubs..."
1910
Joseph Rock first visits Auwahi, makes extensive collections, and remarks about its botanical value in his 1919 book, Indigenous Trees of the Hawaiian Islands.
1920-1921
Charles N. Forbes explores Auwahi, makes extensive collections, and provides some of the best early documentation of the area in his unpublished field notes.
1915-1945
The western portion of Auwahi is protected from cattle grazing by "nearly solid understory" of the weedy Mexican subshrub, Ageratina adenophora.
1939
After nearly 20 years absence, Joseph Rock returns to Auwahi and is reported to have wept at the deterioration of the Auwahi forest.
mid- to late 1940s
A biological control agent insect is introduced to control Ageratina. The program is successful and in conjunction with a drought, the weed is virtually eliminated.
late 1940s
Kikuyu grass is introduced into the former Auwahi forest to enhance its use as pasture
1967
Colin Lennox and The Nature Conservancy make the first attempt at conservation of Auwahi forests by constructing an exclosure. Due to lack of successful kikuyu grass control, the project is generally perceived as a failure, and the cattle are released back into the exclosure.
early 1980-present
The Native Hawaiian Plant Society (NHPS) builds eleven small exclosures to protect patches of native dryland trees at Auwahi.
1997-present
A multi-agency cooperative effort is made at an experimental dryland forest restoration project at a 10 acre exclosure in western Auwahi. Partners include 'Ulupalakua Ranch, Biological Resources Division, U.S. Geological Survey (BRD-USGS), U.S. Fish and Wildlife Service (USFWS), Native Hawaiian Plant Society (NHPS), Living Indigenous Forest Ecosystems (LIFE), and the public of Maui. The success of this first exclosure leads to a second exclosure of 20 acres, that is currently being restored. At the same time, the Auwahi exclosures have become part of the Leeward Haleakala Watershed Restoration Partnership (LHWRP), an effort to restore forests on leeward East Maui, with a focus on koa (Acacia koa).
Auwahi district on East Maui extends from sea level to about 6800 feet (1790 meters) elevation at the southwest rift of leeward Haleakala volcano. In botanical references, Auwahi currently refers to a centrally located, fairly large (5400 acres) stand of diverse dry forest at 3000-5000 feet (915-1525 meters) elevation surrounded by less diverse forest and more open-statured shrubland on lava. Auwahi contains high native tree diversity with 50 dryland species, many with extremely hard, durable, and heavy wood. To early Hawaiians, forests like Auwahi must have seemed an invaluable source of unique natural materials, especially the wide variety of woods for tool making for agriculture and fishing, canoe building, kapa making, and weapons.
Of the 50 species of native trees at Auwahi,Other miscellaneous uses include edible fruits or seeds, bird lime, cordage, a fish narcotizing agent, firewood, a source of "fireworks", recreation, scenting agents, poi boards, and hlua sled construction.
Nine species of trees (18%) have no recorded uses. In many of these cases, the wood appears to be a good quality durable hardwood for which there were likely ethnobotanical uses despite the lack of references in the literature.
Auwahi has been greatly transformed by burning, grazing, and invasion by non-native plant species. As a result, Auwahi has had much of its original native shrub and understory replaced largely by a thick mat of introduced kikuyu grass (Pennisetum clandestinum). Many native tree species produce viable seed but few seedlings are found and fewer of these survive. Since the late 1960s, Auwahi has been the focus of protection and restoration efforts that continue to this day. Thus far efforts have had only limited success.