Sites In Hawaii Research Articles

Relationships between climate, radial growth and wood properties of mature loblolly pine in Hawaii and a northern and southern site in the southeastern United States

Production rates of loblolly pine (Pinus taeda L.) in favorable exotic environments indicate that full biological expression of growth potential in loblolly pine has not yet been attained in its native range. In previous work, high productivity in a loblolly pine plantation in Hawaii (HI) was hypothesized to be related to a more favorable climate conducive to year round carbon gain. To better understand the role of climate in limiting loblolly pine growth, relationships between radial growth and climate were examined in mature loblolly pine grown on two sites representing the opposite latitudinal ends of its ecological niche, Mississippi (MS) and North Carolina (NC), and on a third site in Hawaii (HI) representing a more favorable exotic environment. Raw ring widths were detrended and chronologies built for each site. At the northernmost site, ring width index (RWI) was positively correlated to February, April and July temperatures, annual mean temperature of the current and previous year, and annual maximum temperature. In MS trees, the only significant correlation between growth and climate was a positive correlation between RWI and November temperature. Growth at the MS site was likely more impacted by frequent hurricanes. In HI trees, no significant correlations between growth and temperature were observed but RWI was significantly related to precipitation during the dry season, which occurred from May–September. Potential anatomical alterations in the earlywood and latewood transition zones and timing of earlywood and latewood formation were indicated and may account for low ring specific gravity and percent latewood in HI trees. The moderate temperatures at the HI site likely supported high productivity but sensitivity to precipitation in HI trees indicates that reductions in water availability may effect loblolly pine growth even under more moderate temperatures when evaporative demand is low.

Interpersonal and Social Values Conflict Among Coastal Recreation Activity Groups in Hawaii

We report on user conflicts at six Hawaiian beaches and compare the extent to which evaluations of coastal recreation conflicts differ among groups. This information can be used to help understand current recreation users at coastal sites in Hawaii. Exploratory factor analyses supported a multidimensional interpersonal conflict factor based on four activity subgroups and a multidimensional social values conflict factor based on three activity subgroups. In this study, interpersonal and social values conflicts of Hawaii recreationists align themselves by recreation activity group and not by behavior. ANOVAs and t-tests were used to assess the conflict differences according to gender, residency status, location, age, and recreation activities. A discussion follows regarding the implications of our findings on managing conflict and users.

Wave power extraction by arbitrary arrays of non-diffracting oscillating water columns

A model to predict wave power conversion from arbitrary arrays of oscillating water columns is presented. Based on linear potential theory and idealized non-diffracting machines, it relies on a published analytical solution for the flow field generated by a single oscillating pressure patch on the ocean surface. Estimates of wave power conversion are obtained for several array configurations and well-defined wave resources at two sites in Hawaii, using a single-processor computer. Such results illustrate the versatility and computational efficiency of the model. The proposed approach allows a relatively easy evaluation of interferences among individual machines. This would be useful in optimizing the spatial arrangement of oscillating water columns in large wave farms.

Is “Acceptable” Really Acceptable? Comparing Two Scales for Measuring Normative Evaluations in Outdoor Recreation

This research note compares the commonly used scale of “very unacceptable” to “very acceptable” with an alternative scale of “should definitely not allow” to “should definitely allow” for measuring normative evaluations. Data were obtained from 1,422 users at six sites in Hawaii, and norms were measured in questionnaires with photographs depicting increasing use densities. Responses differed statistically between scales with users feeling that there should be more people allowed than they thought were acceptable at each site. The “acceptance” scale also generated more crystallization or agreement, but lower intensity or importance of use levels than the scale based on “should.” Effect sizes, however, showed that the magnitude of these differences was small or minimal, suggesting that the “acceptance” scale may be appropriate.

Utilizing multichannel electrical resistivity methods to examine the dynamics of the fresh water–seawater interface in two Hawaiian groundwater systems

Multichannel electrical resistivity (ER) measurements were conducted at two contrasting coastal sites in Hawaii to obtain new information on the spatial scales and dynamics of the fresh water–seawater interface and rates of coastal groundwater exchange. At Kiholo Bay (located on the dry, Kona side of the Big Island) and at a site in Maunalua Bay (Oahu), there is an evidence for abundant submarine groundwater discharge (SGD). However, the hydrologic and geologic controls on coastal groundwater discharge are likely to be different at these two sites. While at Kiholo Bay SGD is predominantly through lava tubes, at the Maunalua Bay site exchange occurs mostly through nearshore submarine springs. In order to calculate SGD fluxes, it is important to understand the spatial and temporal scales of coastal groundwater exchange. From ER time series data, subsurface salinity distributions were calculated using site‐specific formation factors. A salinity mass balance box model was then used to calculate rates of point source (i.e., spatially discreet) and total fresh water discharge. From these data, mean SGD rates were calculated for Kiholo Bay (∼9,200 m3/d) and for the Maunalua Bay site (∼5,900 m3/d). While such results are on the same order of magnitude to geochemical tracer‐derived SGD rates, the ER SGD rates provide enhanced details of coastal groundwater exchange that can enable a more cohesive whole watershed perspective.

Intergenerational Shared Sites in Hawaii

Hawaii is often referred to as “the melting pot of the Pacific.” Multicultural diversity is embedded in the DNA of the state and its residents. Two Hawaii-based shared site programs, the Seagull Sc...

Field leaching of pesticides at five test sites in Hawaii: modeling flow and transport

Physically based tier-II models may serve as possible alternatives to expensive field and laboratory leaching experiments required for pesticide approval and registration. The objective of this study was to predict pesticide fate and transport at five different sites in Hawaii using data from an earlier field leaching experiment and a one-dimensional tier-II model. As the predicted concentration profiles of pesticides did not provide close agreement with data, inverse modeling was used to obtain adequate reactive transport parameters. The estimated transport parameters of pesticides were also utilized in a tier-I model, which is currently used by the state authorities to evaluate the relative leaching potential. Water flow in soil profiles was simulated by the tier-II model with acceptable accuracy at all experimental sites. The observed concentration profiles and center of mass depths predicted by the tier-II simulations based on optimized transport parameters provided better agreements than did the non-optimized parameters. With optimized parameters, the tier-I model also delivered results consistent with observed pesticide center of mass depths. Tier-II numerical modeling helped to identify relevant transport processes in field leaching of pesticides. The process-based modeling of water flow and pesticide transport, coupled with the inverse procedure, can contribute significantly to the evaluation of chemical leaching in Hawaii soils.

Epiphytes preferentially colonize high-phosphorus host trees in unfertilized Hawaiian montane forests

Previous research in phosphorus-fertilized Hawaiian montane forests has demonstrated that cyanolichens respond to elevated canopy phosphorus (P) availability by increasing in abundance and diversity; a similar but more muted response is seen for chlorolichens and mosses. In this study, I ask whether P also controls cyanolichen abundance in five unfertilized Hawaiian forests, four on the island of Kauai and one on Hawaii. In three of the four Kauai sites, trees which hosted abundant cyanolichens had significantly higher foliar P content than trees with sparse cyanolichen growth. In the Hawaii site, both foliar P and bark P content were significantly higher on high-cyanolichen cover trees (0.074% vs. 0.053% for leaves, p < 0.001, and 0.085% vs. 0.035% for bark, p < 0.001). Chlorolichen and bryophyte abundance were best predicted by cyanolichen abundance at three out of four of the Kauai sites. These results suggest that host tree P content may be an important factor controlling the abundance of cyanolichens in unfertilized Hawaiian forests, and that cyanolichens may facilitate colonization by chlorolichens and mosses.

Field leaching of pesticides at five test sites in Hawaii: study description and results

Following the discovery of pesticides in wells, the Hawaii Department of Agriculture (HDOA) supported research to evaluate the likelihood of pesticide leaching to the groundwater in Hawaii. The aim of this study was to evaluate the relative leaching pattern of five pesticides at five different sites on three islands and to compare their leaching behavior with bromide and a reference chemical (atrazine) that is known to leach in Hawaiian conditions. Laboratory measurements of sorption and degradation of the pesticides were made. Most of the applied mass of pesticides was still present in the top 80 cm after the 16 week study period. The aggregated oxisol at Kunia showed the most intensive leaching among the five sites. The revised attenuation factor screening approach used by the HDOA indicated that all chemicals, with the exception of trifloxystrobin, had the potential to leach. Similarly, the groundwater ubiquity score ranked trifloxystrobin as a non-leacher. The field leaching data, however, suggested that trifloxystrobin was the most mobile compound among the pesticides tested. Although the results were variable among the sites, the field and laboratory experiments provided useful information for regulating use of these pesticides in Hawaii.

Sky Surface Brightness at Mount Graham: UBVRI Science Observations with the Large Binocular Telescope

ABSTRACTWe present the measurements of sky surface brightness on Mount Graham International Observatory obtained during the first binocular-mode science runs at the Large Binocular Telescope (LBT). A total of 860 images obtained on 23 moonless nights during the period February 2008–June 2008 were analyzed with our data quality assessment procedure. These data, taken at the solar minimum, show that Mt. Graham, in photometric conditions, still has one of the darkest skies, competing with the other first-class observatories. The zenith-corrected values are 21.98, 22.81, 21.81, 20.82, and 19.78 mag arcsec-2 in U, B, V, R, and I, respectively. In photometric conditions, the sky background is ∼0.1 mag arcsec-2 higher than the median when observing toward Tucson and Phoenix. but it may be up to ∼0.5 mag arcsec-2 higher in nonphotometric conditions. The sky at Mt. Graham is ∼0.32 mag arcsec-2 brighter at air mass ∼1.4 than at zenith, but no significant trend was found with the time of night. We demonstrated the dependence of the sky background at Mt. Graham on the solar activity for the first time. In fact, in 2008, at B and V bands, the sky was ∼0.3 mag arcsec-2 darker than in 1999–2002. With these results, we conclude that Mt. Graham is still a first-class observing site, comparable to the darkest sites in Hawaii, Chile, and the Canary Islands.

Fourier Transform Infrared Spectroscopy for Kona Coffee Authentication

Kona coffee, the variety of "Kona typica" grown in the north and south districts of Kona-Island, carries a unique stamp of the region of Big Island of Hawaii, U.S.A. The excellent quality of Kona coffee makes it among the best coffee products in the world. Fourier transform infrared (FTIR) spectroscopy integrated with an attenuated total reflectance (ATR) accessory and multivariate analysis was used for qualitative and quantitative analysis of ground and brewed Kona coffee and blends made with Kona coffee. The calibration set of Kona coffee consisted of 10 different blends of Kona-grown original coffee mixture from 14 different farms in Hawaii and a non-Kona-grown original coffee mixture from 3 different sampling sites in Hawaii. Derivative transformations (1st and 2nd), mathematical enhancements such as mean centering and variance scaling, multivariate regressions by partial least square (PLS), and principal components regression (PCR) were implemented to develop and enhance the calibration model. The calibration model was successfully validated using 9 synthetic blend sets of 100% Kona coffee mixture and its adulterant, 100% non-Kona coffee mixture. There were distinct peak variations of ground and brewed coffee blends in the spectral "fingerprint" region between 800 and 1900 cm(-1). The PLS-2nd derivative calibration model based on brewed Kona coffee with mean centering data processing showed the highest degree of accuracy with the lowest standard error of calibration value of 0.81 and the highest R(2) value of 0.999. The model was further validated by quantitative analysis of commercial Kona coffee blends. Results demonstrate that FTIR can be a rapid alternative to authenticate Kona coffee, which only needs very quick and simple sample preparations.

Inoculating Acacia koa with Bradyrhizobium and Applying Fertilizer in the Nursery: Effects on Nodule Formation and Seedling Growth

Restoration of Acacia koa A. Gray (koa) forests on degraded sites in Hawaii is important for conservation of rare, endemic plants and animals and is often accomplished by planting nursery-grown seedlings. To be successful after outplanting, koa seedlings must access sufficient nutrients from the soil and outcompete other vegetation. Forming symbiotic associations with nitrogen-fixing microorganisms may help alleviate inherent nutrient deficiencies found on volcanic sites, but interactions between inoculation and fertilization during production of koa seedlings are not well studied. Under operational nursery conditions, we fertilized koa seedlings at six controlled-release fertilizer (CRF) rates (ranging from 0 to 11.9 kg·m−3 Osmocote Plus 15N–9P–12K), which were also either inoculated with a locally collected source of nitrogen-fixing Bradyrhizobium spp. or not. Fertilized seedlings were significantly larger than the control; on average, fertilized seedlings were 300% taller and had 180%, 700%, and 350% more root-collar diameter, shoot biomass, and root biomass, respectively. Nitrogen (N) concentration was 23% to 119% greater in fertilized seedlings than nonfertilized seedlings. Inoculation with Bradyrhizobium had no significant affect on seedling characteristics except for root N concentration, which was 8% higher for inoculated seedlings. Fertilizer rate and inoculation interacted to significantly affect nodule number and nodule biomass/seedling. With inoculation, we observed an increase in nodule number (16.5 to 25.5) and biomass (5.8 mg to 11.7 mg) with fertilizer rate up to 4.7 kg·m−3 but a decline to nearly zero at the highest rates. Without inoculation, nodule formation was scarce (3.2 nodules/seedling or less) and only observed when CRF was 2.3 kg·m−3 or less. Our results suggest that high rates of fertilization and successful nodulation are not mutually exclusive nursery practices. Concurrent use of fertilization and inoculation in the nursery may provide opportunity to produce larger seedlings that have high potential to reduce the time needed to achieve canopy closure and thereby help achieve restoration objectives.

Erosion and landscape development decouple strontium and sulfur in the transition to dominance by atmospheric inputs

Weathering and leaching can progressively deplete the pools of soluble, rock-derived elements in soils and ecosystems over millennial time-scales, such that productivity increasingly relies on inputs from atmospheric deposition. This transition has been explored using strontium isotopes, which have been widely assumed to be a proxy for the provenance of other rock-derived elements. We compared rock versus atmospheric proportions of strontium to those for sulfur, a plant macronutrient, at several tropical forest sites in Hawaii and Costa Rica. Isotopic analyses reveal that sulfur is often decoupled from strontium in the transition to atmospheric dependence. Decoupling is likely the result of differences in chemical factors such as atmospheric input rates, mobility in the soil environment, and mineral weathering susceptibility. Strontium and sulfur decoupling appears to be accentuated by the physical process of erosion. Erosion rates are presumed to be high on the Osa Peninsula of Costa Rica, where the recent onset of rapid tectonic uplift has placed the landscape in a transient state. Decoupling is strong there, as erosion has rejuvenated the supply of rock-derived strontium but not sulfur. The landscape response to changes in tectonic uplift on the Osa Peninsula has produced decoupling at the landscape scale. Decoupling is more variable along a Hawaiian catena, presumably due to smaller scale variations in erosion rates and their influence on rejuvenation of rock-strontium inputs. These results illustrate how chemical and physical processes can interact to produce contrasting origins for different nutrient elements in soils and the ecosystems they support.

Thorium-230 coral chronology of a late prehistoric Hawaiian chiefdom

Documenting the history of settlement in Hawaii during the last few centuries before European contact, is crucial to charting the evolution of the most complex chiefdom in Polynesia. It is precisely this period that Hawaii, and many Polynesian societies, underwent their most rapid changes in political, economic and social organisation. The last ∼500 to 300 years in the 14C calibration curve is problematic with wide fluctuations often rendering large age spans that do not precisely date single events, especially troubling with a culture-historical record of ∼1000 years duration. Here we present an extremely high precision 230Th chronology for archaeologically constrained coral samples from a range of occupancy sites. Our high precision dates allow the time of site use to be clearly demonstrated. They also provide the first dates for habitation sites in Hawaii that clearly show contemporaneous occupation—the major problem in settlement pattern archaeology. We demonstrate that two sites were occupied within the same year. Our refined chronology, provides new and exciting opportunities for tracking sociopolitical and economic developments during the last few centuries—the crucial period in the evolution and transformation of Polynesian societies.

The role of abiotic conditions in shaping the long‐term patterns of a high‐elevation Argentine ant invasion

ABSTRACTAnalysis 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 populations over the course of 30 years at a high elevation site in Hawaii suggest that cold and wet conditions have influenced both the ant's distribution and its rate of invasion. In Haleakala National Park on Maui, we found that a population invading at lower elevation is limited by increasing rainfall and presumably by associated decreasing temperatures. A second, higher elevation population has spread outward in all directions, but rates of spread in different directions appear to have been strongly influenced by differences in elevation and temperature. Patterns of foraging activity were strongly tied to soil temperatures, supporting the hypothesis that variation in temperature can influence rates of spread. Based on past patterns of spread, we predicted a total potential range that covers nearly 50% of the park and 75% of the park's subalpine habitats. We compared this rough estimate with point predictions derived from a degree‐day model for Argentine ant colony reproduction, and found that the two independent predictions match closely when soil temperatures are used in the model. The cold, wet conditions that have influenced Argentine ant invasion at this site are likely to be influential at other locations in this species’ current and future worldwide distribution.

The Influence of Nutrient Availability on Soil Organic Matter Turnover Estimated by Incubations and Radiocarbon Modeling

We investigated the decomposability of soil organic matter (SOM) along a chronosequence of rainforest sites in Hawaii that form a natural fertility gradient and at two long-term fertilization experiments. To estimate turnover times and pool sizes of organic matter, we used two independent methods: (1) long-term incubations and (2) a three-box soil model constrained by radiocarbon measurements. Turnover times of slow-pool SOM (the intermediate pool between active and passive pools) calculated from incubations ranged from 6 to 20 y in the O horizon and were roughly half as fast in the A horizon. The radiocarbon-based model yielded a similar pattern but slower turnover times. The calculation of the 14C turnover times is sensitive to the lag time between photosynthesis and incorporation of organic C into SOM in a given horizon. By either method, turnover times at the different sites varied two- or threefold in soils with the same climate and vegetation community. Turnover times were fastest at the sites of highest soil fertility and were correlated with litter decay rates and primary productivity. However, experimental fertilization at the two least-fertile sites had only a small and inconsistent effect on turnover, with N slowing turnover and P slightly speeding it at one site. These results support studies of litter decomposition in suggesting that while plant productivity can respond rapidly to nutrient additions, decomposition may respond much more slowly to added nutrients.

Observing Conditions at Mount Graham: Vatican Advanced Technology Telescope UBVR Sky Surface Brightness and Seeing Measurements from 1999 through 2003

ABSTRACTWe present measurements of sky surface brightness and seeing on Mount Graham, obtained at the Vatican Advanced Technology Telescope (VATT) during 16 observing runs between 1999 April and 2003 December. We show that the sky surface brightness is significantly darker during photometric conditions and can be highly variable over the course of a single observing run, as well as from one run to the next, regardless of photometricity. In our photometric observations, we find an average low air mass (sec z<1.2) sky surface brightness of 22.00, 22.53, 21.49, and 20.88 mag arcsec−2 in U, B, V, and R, respectively. The darkest run (2000 February in U and 2001 February in BVR) had an average sky surface brightness of 22.38, 22.86, 21.72, and 21.19 mag arcsec−2 in U, B, V, and R, respectively. With these results, we show that under the best conditions, Mount Graham can compete with the darkest sites in Hawaii and Chile, thanks in part to the strict dark‐sky ordinances in place in Tucson and Safford. We expect the sky over Mount Graham to be even darker than our 1999–2003 results during solar minimum (2006–2007). We find a significant improvement of about 0 .″45 in our measured stellar FWHM after improvements to the telescope were made in summer and fall 2001. Stellar FWHM values are highly variable, with median R‐band focus FWHM values in each observing run ranging from 0 .″97 to 2 .″15. Significant subarcsecond seeing was occasionally achieved, with values as low as 0 .″65 FWHM in R. There may still be a significant telescope contribution to the seeing at the VATT, but nearby trees as high as the dome are currently the dominant factor.

Influence of Rossby waves on nutrient dynamics and the plankton community structure in the North Pacific subtropical gyre

Nitrate concentrations, chlorophyll a (Chl a) fluorescence, radiance, salinity, and temperature were measured on the Hawaii Air‐Sea Logging Experiment, A Long‐Term Oligotrophic Habitat Assessment (HALE ALOHA) mooring located near the Hawaii Ocean Time‐Series (HOT) Program's Station ALOHA (22°45′N; 158°W). Nitrate concentrations were determined with OsmoAnalyzers deployed at depths of 120 and 180 m. Deployments in 1997 and 1999 captured monthlong events that brought relatively cold high‐nitrate seawater up into the euphotic zone. These events were correlated with negative sea surface height (SSH) anomalies measured by the TOPEX/Poseidon satellite altimeter. These nutrient injections at the Hawaii site were predominantly associated with first baroclinic mode Rossby waves. Elevated nitrate concentrations resulted in increased Chl a concentrations, increased primary productivity, and shifts in the phytoplankton community structure, as determined by HPLC analysis of pigment concentrations. The relative increase in pigments associated with phytoplankton that can grow rapidly and exploit nitrate (e.g., haptophytes and pelagophytes) coincided with the passage of Rossby waves in 1997–1999. A long‐term combination of satellite remote sensing, moored instrumentation or remote vehicles and periodic ship‐based sampling is needed to fully characterize the spatial and temporal variability due to the passage of Rossby waves and their associated biological responses.

Radiology Resources on the Net

Radiology Resources on the Net

Phytoremediation in subtropical Hawaii—A review of over 100 plant species

AbstractPhytoremediation is an emerging remediation technology that utilizes plants and microbes to clean up contaminated air, soil, and water. Tropical and subtropical environments have an advantage in that long plant‐growing seasons and increased soil temperature can accelerate phytoremediation processes. Various contaminated sites in Hawaii have been addressed using this technology. In this article, work progress and advances of phytoremediation are briefly reviewed and exemplified with seven chemically contaminated sites in Hawaii. The investigations were performed for one or more of the following remediation needs: explosive residues, hydrocarbons, pesticide residues, soil stabilization, and slaughterhouse wastewater. In this unique article, studies of testing of over 100 plant species for remediation are reviewed and documented. The general trend leads one to consider that salt‐ and/or drought‐tolerant plants can bear other potential stress‐inducing conditions. © 2004 Wiley Periodicals, Inc.