Arthur Medeiros is a researcher emeritus for PIERC, retiring in 2015 after over 20 years of federal service. Dr. Medeiros worked as a research botanist on Maui Island and was instrumental in the restoration of a Hawaiian dry forest in the Auwahi district of Haleakalā volcano. His efforts led to the recovery of multiple rare dry forest tree species and a 75% increase in native shrub cover.
Overview of Dr. Medeiros' most recent PIERC projects:
Limiting factors for dryland forest restoration on Maui Island, Hawai‘i:
Globally, tropical dry forests are among the most diverse and threatened of ecosystems. Hawaiian dry forests are the most fragmented, reduced, and ecologically degraded ecosystems in the archipelago with less than 10% of their original area remaining. Despite this, Hawaiian dry forests remain important natural refugia. Culturally, dry forests are renowned by native Hawaiians for ethnobotanical source materials, especially durable hardwoods for tools and weapons, and species with utilitarian, medicinal or religious significance. Biologically, Hawaiian dry forests harbor high numbers of threatened plant species with more than 25% of Federally-listed Endangered Hawaiian plant species restricted to dry forest or dry scrub ecosystems. Loss and degradation of the patchwork of Hawaiian dry forest types has been caused by fire and the proliferation of non-native species, particularly feral and domestic ungulates, fire-adapted grasses, and rodent species. Without the development of more effective restoration strategies, most experts agree remaining examples of Hawaiian dry forests likely will be lost in the next 50-100 years. USGS is studying strategies for forest restoration at two sites on the island of Maui: Auwahi and Puu-o-kali.
Beginning in 1845, Auwahi’s forest understory was destroyed by cattle grazing and replaced by extensive stands of the invasive grass kikuyu grass Cenchrus clandestinus. By the late 1960s, approximately 95% of ca. 4000 ha of Auwahi dry forest on leeward Haleakala had been destroyed. The rarity of the Auwahi forest type and with its characteristically high tree diversity (49 species) combined with continued forest decline and the troubling long-term (50-100 years) failure of native tree reproduction prompted a regional biological inventory to describe Auwahi as a ‘museum forest’, i.e. a high diversity forest lacking recruitment.
In 1997, USGS-PIERC and landowner Ulupalakua Ranch with U.S. Fish and Wildlife Service funding initiated a restoration project with the goal of evaluating restoration using ungulate exclusion, weed control, and mass planting native shrub-tree seedlings. The second USGS-PIERC dry forest research restoration project, Puu-o-kali, is regarded as the best remaining example of low elevation dry forest in the Hawaiian Islands. These lava flows are especially rich in biological diversity due to the historically low fire frequency and low cover of invasive plants. Prior to 2001, the endemic wiliwili (Erythrina sandwicensis) (Fabaceae), the dominant tree species of lower-elevation Hawaiian dry forests and the Puu-o-kali area, was virtually free from attacks by non-native insects.
Two recently introduced insect species now threaten the status of Hawaiian Erythrina sandwicensis forests: First detected in Hawaii in 2001, the African bruchid beetle Specularius impressithorax (Pic) (Coleoptera: Chrysomelidae: Bruchinae) became established on all main islands within two years. The erythrina gall wasp (EGW), Quadrastichus erythrinae (Hymenoptera: Eulophidae), believed native to Africa, was first detected in the U.S. on Oahu island in April 2005 and had spread to all main Hawaiian Islands in less than six months. EGW is currently a serious pest of ornamental and native Erythrina (coral trees) on five continents, including nearly the entire tropical and subtropical zones. In Hawaii, EGW has severely impacted the Hawaiian endemic Erythrina sandwicensis, a keystone species of low-elevation dryland forests and an important Hawaiian cultural and ethnobotanical resource. Thousands of individuals of Erythrina sandwicensis have died since 2005 throughout extensive stands in Hawaii due to EGW-induced foliar loss. The USGS-PIERC study site Puu-o-kali has become a primary site in documenting the devastating impacts of two invasive insect species on the keystone dry forest tree Erythrina sandwicensis.
Developing a science basis for forest restoration for the Leeward Haleakalā Watershed Restoration Partnership:
The southern slopes of Haleakalā volcano, which form the bulk of Maui island, are notable for their former biological diversity and their current state of ecological degradation. Though one naturalist noted that formerly koa reached “the state of perfection” on southern Haleakalā, native koa watershed forests now occupy less than 11% of their former extents. An analysis of regional species loss in the Hawai‘i described leeward Haleakalā as the epicenter of extinction in the Hawaiian archipelago. In many areas, not only have native watershed forest been destroyed but large populations of feral goats (Capra hircus) have left extensive hardpan areas with high levels of erosion and sediment transfer. A former head of the State of Hawai‘i Division of Forestry and Wildlife, Michael Buck, has described this area as “Hawai‘i’s biggest embarrassment.”
In the 1980s through 1990s, PIERC led extensive biological surveys of leeward Haleakala which helped in developing familiarity and trust between biologists and regional landowners, especially private large ranches such as Ulupalakua and Haleakalā Ranches both of which harbor natural resources on a caliber potentially similar to National Parks. With growing communal appreciation of regional deforestation problems as well as the potential for regional solutions, USGS was a founding and signing partner to the 43,175 acre Leeward Haleakalā Watershed Restoration Partnership (LHWRP) (www.lhwrp.org).
Supportive LHWRP partner agencies include Environmental Protection Agency, County of Maui Department of Water, U.S. Fish and Wildlife Service, Hawai‘i Community Foundation, and the Natural Resource Conservation Service.
In 2011, an especially diverse 1,500-acre section of forest on south Haleakalā at Kahikinui was designated a Natural Area Reserve (NAR), the State of Hawai‘i’s highest form of land protection. Part of the expressed rationale for the formation of the NAR was the reintroduction of the critically endangered forest passerine, the Maui parrotbill (Psuedonestor xanthophyrs). The Maui Parrotbill is a specialized offshoot of the often nectar-feeding Hawaiian honeycreepers. It is listed as Endangered by the US Fish and Wildlife Service with current population estimates of less than 500 individuals and declining population trends. Many experts believe restored koa forest on southern Haleakalā at Kahikinui and Nakula is the best chance for survival for one of the rarest songbirds in the United States.
Below are publications associated with this project.
Shifts in an invasive rodent community favoring black rats (Rattus rattus) following restoration of native forest
Dry forest restoration and unassisted native tree seedling recruitment at Auwahi, Maui
Diet and conservation implications of an invasive chameleon, Chamaeleo jacksonii (Squamata: Chamaeleonidae) in Hawaii
Weeds of Hawaii’s lands devoted to watershed protection and biodiversity conservation: Role of biological control as the missing piece in an integrated pest management strategy
Trip report: pilot study of factors linking watershed function and coastal ecosystem health in American Samoa
Systemically applied insecticides for treatment of erythrina gall wasp, quadrastichus erythrinae kim hymenoptera: Eulophidae
A preliminary assessment of mouflon abundance at the Kahuku Unit of Hawaii Volcanoes National Park
The role of abiotic conditions in shaping the long-term patterns of a high-elevation Argentine ant invasion
Interaction between the Hawaiian dark-rumped petrel and the Argentine ant in Haleakala National Park, Maui, Hawaii
- Overview
Arthur Medeiros is a researcher emeritus for PIERC, retiring in 2015 after over 20 years of federal service. Dr. Medeiros worked as a research botanist on Maui Island and was instrumental in the restoration of a Hawaiian dry forest in the Auwahi district of Haleakalā volcano. His efforts led to the recovery of multiple rare dry forest tree species and a 75% increase in native shrub cover.
Overview of Dr. Medeiros' most recent PIERC projects:
Limiting factors for dryland forest restoration on Maui Island, Hawai‘i:
Globally, tropical dry forests are among the most diverse and threatened of ecosystems. Hawaiian dry forests are the most fragmented, reduced, and ecologically degraded ecosystems in the archipelago with less than 10% of their original area remaining. Despite this, Hawaiian dry forests remain important natural refugia. Culturally, dry forests are renowned by native Hawaiians for ethnobotanical source materials, especially durable hardwoods for tools and weapons, and species with utilitarian, medicinal or religious significance. Biologically, Hawaiian dry forests harbor high numbers of threatened plant species with more than 25% of Federally-listed Endangered Hawaiian plant species restricted to dry forest or dry scrub ecosystems. Loss and degradation of the patchwork of Hawaiian dry forest types has been caused by fire and the proliferation of non-native species, particularly feral and domestic ungulates, fire-adapted grasses, and rodent species. Without the development of more effective restoration strategies, most experts agree remaining examples of Hawaiian dry forests likely will be lost in the next 50-100 years. USGS is studying strategies for forest restoration at two sites on the island of Maui: Auwahi and Puu-o-kali.
Beginning in 1845, Auwahi’s forest understory was destroyed by cattle grazing and replaced by extensive stands of the invasive grass kikuyu grass Cenchrus clandestinus. By the late 1960s, approximately 95% of ca. 4000 ha of Auwahi dry forest on leeward Haleakala had been destroyed. The rarity of the Auwahi forest type and with its characteristically high tree diversity (49 species) combined with continued forest decline and the troubling long-term (50-100 years) failure of native tree reproduction prompted a regional biological inventory to describe Auwahi as a ‘museum forest’, i.e. a high diversity forest lacking recruitment.
In 1997, USGS-PIERC and landowner Ulupalakua Ranch with U.S. Fish and Wildlife Service funding initiated a restoration project with the goal of evaluating restoration using ungulate exclusion, weed control, and mass planting native shrub-tree seedlings. The second USGS-PIERC dry forest research restoration project, Puu-o-kali, is regarded as the best remaining example of low elevation dry forest in the Hawaiian Islands. These lava flows are especially rich in biological diversity due to the historically low fire frequency and low cover of invasive plants. Prior to 2001, the endemic wiliwili (Erythrina sandwicensis) (Fabaceae), the dominant tree species of lower-elevation Hawaiian dry forests and the Puu-o-kali area, was virtually free from attacks by non-native insects.
Two recently introduced insect species now threaten the status of Hawaiian Erythrina sandwicensis forests: First detected in Hawaii in 2001, the African bruchid beetle Specularius impressithorax (Pic) (Coleoptera: Chrysomelidae: Bruchinae) became established on all main islands within two years. The erythrina gall wasp (EGW), Quadrastichus erythrinae (Hymenoptera: Eulophidae), believed native to Africa, was first detected in the U.S. on Oahu island in April 2005 and had spread to all main Hawaiian Islands in less than six months. EGW is currently a serious pest of ornamental and native Erythrina (coral trees) on five continents, including nearly the entire tropical and subtropical zones. In Hawaii, EGW has severely impacted the Hawaiian endemic Erythrina sandwicensis, a keystone species of low-elevation dryland forests and an important Hawaiian cultural and ethnobotanical resource. Thousands of individuals of Erythrina sandwicensis have died since 2005 throughout extensive stands in Hawaii due to EGW-induced foliar loss. The USGS-PIERC study site Puu-o-kali has become a primary site in documenting the devastating impacts of two invasive insect species on the keystone dry forest tree Erythrina sandwicensis.
Developing a science basis for forest restoration for the Leeward Haleakalā Watershed Restoration Partnership:
The southern slopes of Haleakalā volcano, which form the bulk of Maui island, are notable for their former biological diversity and their current state of ecological degradation. Though one naturalist noted that formerly koa reached “the state of perfection” on southern Haleakalā, native koa watershed forests now occupy less than 11% of their former extents. An analysis of regional species loss in the Hawai‘i described leeward Haleakalā as the epicenter of extinction in the Hawaiian archipelago. In many areas, not only have native watershed forest been destroyed but large populations of feral goats (Capra hircus) have left extensive hardpan areas with high levels of erosion and sediment transfer. A former head of the State of Hawai‘i Division of Forestry and Wildlife, Michael Buck, has described this area as “Hawai‘i’s biggest embarrassment.”
In the 1980s through 1990s, PIERC led extensive biological surveys of leeward Haleakala which helped in developing familiarity and trust between biologists and regional landowners, especially private large ranches such as Ulupalakua and Haleakalā Ranches both of which harbor natural resources on a caliber potentially similar to National Parks. With growing communal appreciation of regional deforestation problems as well as the potential for regional solutions, USGS was a founding and signing partner to the 43,175 acre Leeward Haleakalā Watershed Restoration Partnership (LHWRP) (www.lhwrp.org).
Supportive LHWRP partner agencies include Environmental Protection Agency, County of Maui Department of Water, U.S. Fish and Wildlife Service, Hawai‘i Community Foundation, and the Natural Resource Conservation Service.
In 2011, an especially diverse 1,500-acre section of forest on south Haleakalā at Kahikinui was designated a Natural Area Reserve (NAR), the State of Hawai‘i’s highest form of land protection. Part of the expressed rationale for the formation of the NAR was the reintroduction of the critically endangered forest passerine, the Maui parrotbill (Psuedonestor xanthophyrs). The Maui Parrotbill is a specialized offshoot of the often nectar-feeding Hawaiian honeycreepers. It is listed as Endangered by the US Fish and Wildlife Service with current population estimates of less than 500 individuals and declining population trends. Many experts believe restored koa forest on southern Haleakalā at Kahikinui and Nakula is the best chance for survival for one of the rarest songbirds in the United States.
- Publications
Below are publications associated with this project.
Shifts in an invasive rodent community favoring black rats (Rattus rattus) following restoration of native forest
One potential, unintended ecological consequence accompanying forest restoration is a shift in invasive animal populations, potentially impacting conservation targets. Eighteen years after initial restoration (ungulate exclusion, invasive plant control, and out planting native species) at a 4 ha site on Maui, Hawai'i, we compared invasive rodent communities in a restored native dry forest and adjaAuthorsAaron B. Shiels, Arthur C. Medeiros, Erica I. von AllmenDry forest restoration and unassisted native tree seedling recruitment at Auwahi, Maui
Efforts to restore highly degraded but biologically significant forests draw from a limited toolbox. With less than 10% of their former distribution remaining, Hawaiian dry forests, though critically endangered, remain important biological and cultural refugia. At restoration onset (1997), vegetation of restoration and control areas of degraded Auwahi dry forest, Maui Island, was similar, dominateAuthorsArthur C. Medeiros, E. I. von Allmen, C.G. ChimeraDiet and conservation implications of an invasive chameleon, Chamaeleo jacksonii (Squamata: Chamaeleonidae) in Hawaii
We summarize information on current distribution of the invasive lizard Chamaeleo jacksonii and predict its potential distribution in the Hawaiian Islands. Potential distribution maps are based on climate models developed from known localities in its native range and its Hawaiian range. We also present results of analysis of stomach contents of a sample of 34 chameleons collected from native, predAuthorsFred Kraus, Arthur Medeiros, David Preston, Catherine S. Jarnevich, Gordon H. RoddaWeeds of Hawaii’s lands devoted to watershed protection and biodiversity conservation: Role of biological control as the missing piece in an integrated pest management strategy
Despite Hawaii’s reputation as an extinction icon, significant biological resources remain, especially in watersheds, natural areas, and specialized edaphic sites (e.g., lava dry forest, coastal). While direct habitat destruction by humans continues, human-facilitated biological invaders are currently the primary agents of continuing degradation. The ability of invasive plants to have prolific seeAuthorsArthur C. Medeiros, L.L. LoopeTrip report: pilot study of factors linking watershed function and coastal ecosystem health in American Samoa
Coral reef resources in the territory of American Samoa face significant problems from overfishing, non-point source pollution, global warming, and continuing population growth and development. The islands are still relatively isolated relative to other parts of the Pacific and have managed to avoid some of the more devastating invasive species that have reached other archipelagoes. As a result, tAuthorsCarter T. Atkinson, Arthur C. MedeirosSystemically applied insecticides for treatment of erythrina gall wasp, quadrastichus erythrinae kim hymenoptera: Eulophidae
Abstract The erythrina gall wasp (EGW), believed native to Africa, is a recently described species and now serious invasive pest of Erythrina (coral trees) in tropical and subtropical locales. Erythrina are favored ornamental and landscape trees, as well as native members of threatened ecosystems. The EGW is a tiny, highly mobile, highly invasive wasp that deforms (galls) host trees causing severeAuthorsJ.J. Doccola, S.L. Smith, B.L. Strom, A.C. Medeiros, E. Von AllmenA preliminary assessment of mouflon abundance at the Kahuku Unit of Hawaii Volcanoes National Park
Hawaii Volcanoes National Park (HAVO) recently acquired the 115,653 acre Kahuku Ranch unit adjacent to the existing Mauna Loa section of HAVO. Kahuku contains numerous exceptional natural resources including many federally listed threatened and endangered species. An apparently large and growing population of alien mouflon sheep (Ovis gmelini musimon), however, threatens sensitive native plants anAuthorsSteven C. Hess, Ben Kawakami, David Okita, Keola MedeirosThe role of abiotic conditions in shaping the long-term patterns of a high-elevation Argentine ant invasion
Analysis of long-term patterns of invasion can reveal the importance of abiotic factors in influencing invasion dynamics, and can help predict future patterns of spread. In the case of the invasive Argentine ant (Linepithema humile), most prior studies have investigated this species' limitations in hot and dry climates. However, spatial and temporal patterns of spread involving two ant populationsAuthorsP.D. Krushelnycky, S.M. Joe, A.C. Medeiros, C.C. Daehler, L.L. LoopeInteraction between the Hawaiian dark-rumped petrel and the Argentine ant in Haleakala National Park, Maui, Hawaii
The endemic biota of the Hawaiian islands is believed to have evolved in the absence of ant predation. However, it was suspected that this endemic biota is highly vulnerable to the effect of immigrant ants especially with regard to an aggressive predator known as the Argentine ant (Linepithema humile). First recorded in the Haleakala National Park on the island of Maui in 1967, this ant was believAuthorsPaul D. Krushelnycky, Cathleen S.N. Hodges, Arthur C. Medeiros, Lloyd L. Loope