Visiting a Climate-Influenced National Park: The Stability of Climate Change Perceptions

Understanding perceptions of global environmental issues, such as climate change, can help inform resource management, policy development, and communication with constituents. Although a considerable amount of research documents citizens’ perceptions of climate change, few have investigated how interactions with climate-impacted parks and protected areas influence these perceptions, and consequently elements of environmental management. Using a mixed methods Instrument Development Approach, the researchers examined the stability of park visitors’ (N = 429) climate change perceptions during a daylong interaction with climate-sensitive and influenced resources at Kenai Fjords National Park in Alaska. Results indicate that global-level beliefs about climate change remained relatively stable during a park experience, but perceptions about climate change at the park-level (e.g., impacts) appeared more malleable. Findings also revealed the type of park experience (terrestrial vs. marine) can influence the degree of change in visitors’ perceptions. Implications for communication, outreach, and park management are discussed.     

Fundamental trade-offs generating the worldwide leaf economics spectrum

Recent work has identified a worldwide "economic" spectrum of correlated leaf traits that affects global patterns of nutrient cycling and primary productivity and that is used to calibrate vegetation-climate models. The correlation patterns are displayed by species from the arctic to the tropics and are largely independent of growth form or phylogeny. This generality suggests that unidentified fundamental constraints control the return of photosynthates on investments of nutrients and dry mass in leaves. Using novel graph theoretic methods and structural equation modeling, we show that the relationships among these variables can best be explained by assuming (1) a necessary trade-off between allocation to structural tissues versus liquid phase processes and (2) an evolutionary tradeoff between leaf photosynthetic rates, construction costs, and leaf longevity.     

Effects of cyanobacterium Fischerella ambigua isolates and cell free culture media on zebrafish (Danio rerio) embryo development

The toxic effects of several species of fresh water cyanobacteria, notably Microcystis species and associated toxins, the microcystins, Anabaena species (anatoxin), Nodularia sp. (nodularin), and Cylindrospermopsis raciborskii (cylindrospermopsin), are well known. Little, however, is known about the effects of secondary metabolites other than alkaloids. Early life stage tests with zebrafish (Danio rerio) were used to detect bioactive properties of compounds released by healthy cyanobacteria (Fischerella ambigua), particularly on the early developmental stages of fish. This approach, using F. ambigua is probably most valuable as it shows the toxicity of healthy growing cyanobacteria. The effects of cyanobacterial secondary metabolites on the embryonic stages of fish are of considerable interest as many aquatic creatures, particularly fish, are unable to avoid the potential toxins that may be released by undesirable algal blooms or as a result of allelopathic effects. In the current study, the zebrafish (D. rerio) was used as a model experimental system to investigate the effects of ambigols A and C, tjipanazole D and C, 2,4-dichlorobenzoic acid, cell free culture media, and media extracts of a terrestrial/fresh water strain of the cyanobacterium F. ambigua on embryo development. Fish embryo tests performed with the cell free culture medium showed that after 3h of exposure to undiluted culture medium all fish embryos died. At a tenfold dilution the process of epiboly (formation of the gastrula) was retarded in all embryos, lesions were observed, and their general development was significantly arrested, finally followed by death. The same tests performed with extracts (dichloromethane, n-butanol, and residual cell free culture medium) of the cell free culture medium, ambigol A, ambigol C, 2,4-dichlorobenzoic acid and tjipanazole D showed only ambigol A to have an influence on zebrafish development at concentrations>or=1 mg/l (2.06 microM). After 55 h all embryos showed pectoral oedema, irregularly shaped fin folds, bent tails, and unusual circular neoplasms in the dorsal tail fin fold. Due to the high concentration of ambigol A used in this assay these effects were considered to be of minor importance when compared to those of the culture medium.     

Estimated effects of climate change on flood vulnerability of U.S. bridges

We assessed the potential impacts of increased river flooding from climate change on bridges in the continental United States. Daily precipitation statistics from four climate models and three greenhouse gas (GHG) emissions scenarios (A2, A1B, and B1) were used to capture a range of potential changes in climate. Using changes in maximum daily precipitation, we estimated changes to the peak flow rates for the 100-year return period for 2,097 watersheds. These estimates were then combined with information from the National Bridge Inventory database to estimate changes to bridge scour vulnerability. The results indicate that there may be significant potential risks to bridges in the United States from increased precipitation intensities. Approximately 129,000 bridges were found to be currently deficient. Tens of thousands to more than 100,000 bridges could be vulnerable to increased river flows. Results by region vary considerably. In general, more bridges in eastern areas are vulnerable than those in western areas. The highest GHG emissions scenarios result in the largest number of bridges being at risk. The costs of adapting vulnerable bridges to avoid increased damage associated with climate change vary from approximately $140 to $250 billion through the 21st century. If these costs were spread out evenly over the century, the annual costs would be several billion dollars. The costs of protecting the bridges against climate change risks could be reduced by approximately 30% if existing deficient bridges are improved with riprap.     

Predicting breeding habitat for amphibians: a spatiotemporal analysis across Yellowstone National Park

The ability to predict amphibian breeding across landscapes is important for informing land management decisions and helping biologists better understand and remediate factors contributing to declines in amphibian populations. We built geospatial models of likely breeding habitats for each of four amphibian species that breed in Yellowstone National Park (YNP). We used field data collected in 2000-2002 from 497 sites among 16 basins and predictor variables from geospatial models produced from remotely sensed data (e.g., digital elevation model, complex topographic index, landform data, wetland probability, and vegetative cover). Except for 31 sites in one basin that were surveyed in both 2000 and 2002, all sites were surveyed once. We used polytomous regression to build statistical models for each species of amphibian from (1) field survey site data only, (2) field data combined with data from geospatial models, and (3) data from geospatial models only. Based on measures of receiver operating characteristic (ROC) scores, models of the second type best explained likely breeding habitat because they contained the most information (ROC values ranged from 0.70 to 0.88). However, models of the third type could be applied to the entire YNP landscape and produced maps that could be verified with reserve field data. Accuracy rates for models built for single years were highly variable, ranging from 0.30 to 0.78. Accuracy rates for models built with data combined from multiple years were higher and less variable, ranging from 0.60 to 0.80. Combining results from the geospatial multiyear models yielded maps of "core" breeding areas (areas with high probability values for all three years) surrounded by areas that scored high for only one or two years, providing an estimate of variability among years. Such information can highlight landscape options for amphibian conservation. For example, our models identify alternative areas that could be protected for each species, including 6828-10 764 ha for tiger salamanders, 971-3017 ha for western toads, 4732-16 696 ha for boreal chorus frogs, and 4940-19 690 ha for Columbia spotted frogs.     

The impact of bias in MoM values on patient risk and screening performance for Down syndrome

First and second trimester screening protocols for Down syndrome rely on marker values being referred to smoothed median values to produce adjusted multiple of the median (MoM) values to standardise for factors such as assay, gestation, maternal weight, smoking status, and so on. Changes in assay components, such as reagent lot, and inappropriate use of published regression equations for smoothed medians have resulted in biases in reported MoM values that in many applications remain uncorrected. This paper investigates the impact of these biases on patient-specific risk estimates and screening performance, and concludes that a 10% bias for an individual marker can result in an increase of between 1 and 2% in the false positive rate of the programme. A simple formula is also derived that enables the impact of these biases to be determined without the need for simulation, thus making it easier to design effective statistical quality control procedures to monitor the output of screening software algorithms. Objective To determine the impact of bias in MoM values on detection rates, false positive rates and patient-specific risks for Down syndrome. Methods We show that bias in MoM values affects risk through a multiplicative factor, and present an approximation to estimate this factor. We then show how bias in MoM values changes the effective risk threshold in the screening test, and hence the test's performance characteristics are determined by reference to a different point on the ROC curve for that test. Our approximation is based on the assumption of equal variance covariance structure for the unaffected and T21 log MoM values. We demonstrate, using computer simulation and supportive theoretical results, that the approximation is reliable in situations encountered in practice. Applications of the approximation are also discussed in respect of establishing effective quality control rules for median MoMs. Results Substantial changes in patient risk estimates and overall screening performance can result from the sort of biases in marker MoM values encountered in routine practice. In particular, biases of 10% in individual median marker MoM values can produce a four-fold range of risks when using the triple test. A 10% bias in a single marker will change the false positive rates by up to 2%. The effects on the false positive rate are approximately additive and, in cases where all markers are biased towards Down syndrome, biases in all three markers for the triple test can more than double the false positive rate. Conclusions Biases in marker MoM values can occur in many ways, inappropriate median values, kit lot change, drift in assay performance and operator effects. We present methods which allow the impact of these changes to be assessed in relation to patient-specific risks and the overall screening performance. This, in turn, will enable appropriate quality control procedures to be established to control the magnitude of reported marker MoM biases, or equivalently, the magnitude of biases associated with the calculation of patient-specific risks. Copyright © 2007 John Wiley & Sons, Ltd.     

Assessment of harbor seal predation on adult salmonids in a Pacific Northwest estuary.

The populations of many native species have increased or expanded in distribution in recent decades, sometimes with negative consequences to sympatric native species that are rarer or less adaptable to anthropogenic changes to the environment. An example of this phenomenon from the Pacific Northwest is predation by locally abundant pinnipeds (seals and sea lions) on threatened, endangered, or otherwise depleted salmonid (Oncorhynchus spp.) populations. We used survey sampling methodology, acoustic telemetry, and molecular genetics to quantify the amount of harbor seal (Phoca vitulina) predation on a depressed run of coho salmon (O. kisutch) and to determine whether some seals consumed a disproportionately higher number of salmonids than others. Based on a probability sample totaling 759.5 h of observation, we estimated that seals consumed 1161 adult salmonids (95% CI = 503-1818 salmonids) during daylight hours over an 18.9-km estuarine study area in Oregon during an 84-d period in fall 2002. Simultaneous tracking of 56 seals via an acoustic telemetry array indicated that a small proportion of marked seals (12.5%) exhibited behavior that was consistent with specialization on salmonids. These seals spent the majority of their time in the riverine portion of the study area and did so disproportionately more at night than day. Genetic analysis of 116 salmonid structures recovered from 11 seal fecal samples suggested that coho salmon accounted for approximately one-half of total salmonid consumption. Though subject to considerable uncertainty, the combined results lead us to infer that seals consumed 21% (range = 3-63%) of the estimated prespawning population of coho salmon. We speculate that the majority of the predation occurred upriver, at night, and was done by a relatively small proportion of the local seal population. Understanding the extent and nature of pinniped predation can provide important inputs into risk assessments and other modeling efforts designed to aid the conservation and recovery of salmonids in the Pacific Northwest. Such understanding may also help inform management actions designed to reduce the impact of pinniped predation on salmonids, which potentially range from short-term lethal removal programs to long-term ecosystem restoration and protection efforts.