189 research outputs found

    Description of a new large-scale vegetation mapping project in Hawai'i

    Get PDF
    Western Region, National Park Servic

    Ohia rain forest study: ecological investigations of the ohia dieback problem in Hawaii

    Get PDF
    Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.This final report summarizes the more important results of a two year study of the ohia (Metrosideros collina subsp. polymorpha) rain forest, extending from within Hawaii Volcanoes National Park north across the east flank of Mauna Kea, Island Hawaii. The study focus was on the ohia dieback which occurs in many areas of this terrain. A 1:48,000 vegetation map was produced, which is included in selected copies of this report. In addition, an independent habitat classification was developed from physical soil and moisture regime differences occurring in the area. Over 35 ohia forest stands were sampled in detail for their ohia population structures and 39 releves were analyzed for their floristic content. Five different forms of dieback were recognized. Two of these, called the Dryland and Wetland Diebacks appear to be the more rapid and dramatic forms. Their causes are not from disease or insect attack, but are presumed to be from climatic triggers, acting through the soil. These diebacks are clearly associated with ohia-stand rejuvenation. A third form of dieback, here called Bog-formation Dieback, appears to be a slower form of stand dieback related to permanent site changes. An Ohia-displacement Dieback occurs in the Olaa Tract area, where tree ferns seem to gradually take over the habitats. Here the dieback cause appears to be overmaturity. Individual tree dieback, the fifth form of dieback, is found as an isolated, but common phenomenon in many non-dieback stands examined. All diebacks appear to have natural causes, which are suggested in detail. A new theory is presented, which proposes that there are a number of dynamic phases, including the dieback, which provide for the perpetuation of the shade-intolerant, dominant tree species (ohia) in this rainforest ecosystem.National Park Service Contract No. CX 8000 6 000

    Long-Term Population Variability in the Palila, An Endangered Hawaiian Honeycreeper

    Get PDF
    Annual surveys of the entire range of the endangered Palila (Loxioides bailleui Oustalet) on Mauna Kea, Hawai'i, were conducted during 1980-1995. The majority of the Palila population was found on the southwestern slope of Mauna Kea near Pu'u La'au, and the range of Palila has not changed since 1975. The Palila population was highly variable. Mean population size during 1980-1995 was 3390 ± 333 SE, but the population ranged from 1584 ± 324 in 1985 to 5685 ± 535 in 1981. Population size outside the population center near Pu'u La'au has decreased significantly since 1980

    The distribution, impact and potential management of the introdued vine Passiflora mollissima (Passifloraceae) in Hawai'i

    Get PDF
    Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.Passiflora mollissima, a weedy vine introduced to Hawai'i, infests significant portions of two of the major islands, Hawai'i and Kaua'i. It grows between 600 and 2200 m elevation in areas where the rainfall does not exceed 5100 mm. The vine is distributed continuously over a total of 190 km² and in more widely scattered populations over an additional 330 km². Man has been the principle agent of introduction for this species. However, intermediate-distance dispersal may be affected by introduced gallincaeous birds and cattle. Locally feral pigs are the major dispersal agent. Passiflora mollissima inhabits many of the major upland vegetation types in Hawaii but is most successful in mesic Acacia koa - Metrosideros polymorpha forests. Although over much of its current range its foliage cover is less than 25%, in some areas it is so dense that it smothers large tracts of native forest. Potential impacts of the infestation on depleted and endangered endemic organisms are also discussed. It is concluded that P. mollissima has become too widespread for successful mechanical or chemical control except in are as of recent local introduction. Prospects for biological control of this species are discussed in the context of current research efforts and practical problems related to a commercially grown congener.U.S. Fish and Wildlife Service; Cooperative National Parks Reseach Studies Unit, Department of Botany, University of Hawai’i; Institute of Pacific Islands Forestry, U.S. Forest Service; Hawaii Volcanoes National Park, Resources Management Division; Hawaii Office of the Nature Conservanc

    A prioritization protocol for coastal wetland restoration on Molokaʻi, Hawaiʻi

    Get PDF
    Hawaiian coastal wetlands provide important habitat for federally endangered waterbirds and socio-cultural resources for Native Hawaiians. Currently, Hawaiian coastal wetlands are degraded by development, sedimentation, and invasive species and, thus, require restoration. Little is known about their original structure and function due to the large-scale alteration of the lowland landscape since European contact. Here, we used 1) rapid field assessments of hydrology, vegetation, soils, and birds, 2) a comprehensive analysis of endangered bird habitat value, 3) site spatial characteristics, 4) sea-level rise projections for 2050 and 2100 and wetland migration potential, and 5) preferences of the Native Hawaiian community in a GIS site suitability analysis to prioritize restoration of coastal wetlands on the island of Molokaʻi. The site suitability analysis is the first, to our knowledge, to incorporate community preferences, habitat criteria for endangered waterbirds, and sea-level rise into prioritizing wetland sites for restoration. The rapid assessments showed that groundwater is a ubiquitous water source for coastal wetlands. A groundwater-fed, freshwater herbaceous peatland or “coastal fen” not previously described in Hawaiʻi was found adjacent to the coastline at a site being used to grow taro, a staple crop for Native Hawaiians. In traditional ecological knowledge, such a groundwater-fed, agro-ecological system is referred to as a loʻipūnāwai (spring pond). Overall, 39 plant species were found at the 12 sites; 26 of these were wetland species and 11 were native. Soil texture in the wetlands ranged from loamy sands to silt and silty clays and the mean % organic carbon content was 10.93% ± 12.24 (sd). In total, 79 federally endangered waterbirds, 13 Hawaiian coots (‘alae keʻokeʻo; Fulica alai) and 66 Hawaiian stilts (aeʻo; Himantopus mexicanus knudseni), were counted during the rapid field assessments. The site suitability analysis consistently ranked three sites the highest, Kaupapaloʻi o Kaʻamola, Kakahaiʻa National Wildlife Refuge, and ʻŌhiʻapilo Pond, under three different weighting approaches. Site prioritization represents both an actionable plan for coastal wetland restoration and an alternative protocol for restoration decision-making in places such as Hawaiʻi where no pristine “reference” sites exist for comparison

    Exhausted Cytotoxic Control of Epstein-Barr Virus in Human Lupus

    Get PDF
    Systemic Lupus Erythematosus (SLE) pathology has long been associated with an increased Epstein-Barr Virus (EBV) seropositivity, viremia and cross-reactive serum antibodies specific for both virus and self. It has therefore been postulated that EBV triggers SLE immunopathology, although the mechanism remains elusive. Here, we investigate whether frequent peaks of EBV viral load in SLE patients are a consequence of dysfunctional anti-EBV CD8+ T cell responses. Both inactive and active SLE patients (n = 76 and 42, respectively), have significantly elevated EBV viral loads (P = 0.003 and 0.002, respectively) compared to age- and sex-matched healthy controls (n = 29). Interestingly, less EBV-specific CD8+ T cells are able to secrete multiple cytokines (IFN-γ, TNF-α, IL-2 and MIP-1β) in inactive and active SLE patients compared to controls (P = 0.0003 and 0.0084, respectively). Moreover, EBV-specific CD8+ T cells are also less cytotoxic in SLE patients than in controls (CD107a expression: P = 0.0009, Granzyme B release: P = 0.0001). Importantly, cytomegalovirus (CMV)-specific responses were not found significantly altered in SLE patients. Furthermore, we demonstrate that EBV-specific CD8+ T cell impairment is a consequence of their Programmed Death 1 (PD-1) receptor up-regulation, as blocking this pathway reverses the dysfunctional phenotype. Finally, prospective monitoring of lupus patients revealed that disease flares precede EBV reactivation. In conclusion, EBV-specific CD8+ T cell responses in SLE patients are functionally impaired, but EBV reactivation appears to be an aggravating consequence rather than a cause of SLE immunopathology. We therefore propose that autoimmune B cell activation during flares drives frequent EBV reactivation, which contributes in a vicious circle to the perpetuation of immune activation in SLE patients

    The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): illuminating the functional diversity of eukaryotic life in the oceans through transcriptome sequencing.

    Get PDF
    Microbial ecology is plagued by problems of an abstract nature. Cell sizes are so small and population sizes so large that both are virtually incomprehensible. Niches are so far from our everyday experience as to make their very definition elusive. Organisms that may be abundant and critical to our survival are little understood, seldom described and/or cultured, and sometimes yet to be even seen. One way to confront these problems is to use data of an even more abstract nature: molecular sequence data. Massive environmental nucleic acid sequencing, such as metagenomics or metatranscriptomics, promises functional analysis of microbial communities as a whole, without prior knowledge of which organisms are in the environment or exactly how they are interacting. But sequence-based ecological studies nearly always use a comparative approach, and that requires relevant reference sequences, which are an extremely limited resource when it comes to microbial eukaryotes. In practice, this means sequence databases need to be populated with enormous quantities of data for which we have some certainties about the source. Most important is the taxonomic identity of the organism from which a sequence is derived and as much functional identification of the encoded proteins as possible. In an ideal world, such information would be available as a large set of complete, well curated, and annotated genomes for all the major organisms from the environment in question. Reality substantially diverges from this ideal, but at least for bacterial molecular ecology, there is a database consisting of thousands of complete genomes from a wide range of taxa, supplemented by a phylogeny-driven approach to diversifying genomics [2]. For eukaryotes, the number of available genomes is far, far fewer, and we have relied much more heavily on random growth of sequence databases, raising the question as to whether this is fit for purpose
    corecore