Not just the usual suspects: insect herbivore populations and communities are associated with multiple plant nutrients

The relationship between plant nutrient content and insect herbivore populations and community structure has long interested ecologists. Insect herbivores require multiple nutrients, but ecologists have focused mostly on nitrogen (an estimate of plant protein content), and more recently phosphorus (P); other nutrients have received little attention. Here we document nutrient variation in grass and forb samples from grassland habitats in central Nebraska using an elemental approach; in total we measured foliar concentrations of 12 elements (N and P, plus S, B, Ca, Mg, Na, K, Zn, Fe, Mn, and Cu). We detected significant variability among sites for N, P, Mg, Na, K, and Cu. We next used a model selection approach to explore how this nutritional variation and plant biomass correlate with grasshopper densities (collectively and at the feeding-guild level), and principal component analysis to explore nutrient correlations with grasshopper community species composition. When all grasshoppers were pooled, densities varied among sites, but only P was associated with abundance of the elements shown to vary between sites. Different responses occurred at the feeding-guild level. For grass specialists, densities were associated with N, plus P, Mg, and Na. For forb specialists, N and P were often associated with density, but associations with Na and K were also observed. Finally, mixed-feeder abundance was strongly associated with biomass, and to a lesser extent P, Mg, Na, and Cu. At the community level, B, Ca, Zn, and Cu, plus biomass, explained > 30% of species composition variation. Our results confirm the positive association of N and P with insect herbivore populations, while suggesting a potential role for Mg, Na, and K. They also demonstrate the importance of exploring effects at the feeding-guild level. We hope our data motivate ecologists to think beyond N and P when considering plant nutrient effects on insect herbivores, and make a call for studies to examine functional responses of insect herbivores to dietary manipulation of Mg, Na, and K. Finally, our results demonstrate correlations between variation in nutrients and species assemblages, but factors not linked to plant nutrient quality or biomass likely explain most of the observed variation.     

An agent-based model of red colobus resources and disease dynamics implicates key resource sites as hot spots of disease transmission

The effect of anthropogenic landscape change on disease in wildlife populations represents a growing conservation and public health concern. Red colobus monkeys (Procolobus rufomitratus), an endangered primate species, are particularly susceptible to habitat alteration and have been the focus of a great deal of disease and ecological research as a result. To infer how landscape changes can affect host and parasite dynamics, a spatially explicit agent-based model is created to simulate movement and foraging of this primate, based on a resource landscape estimated from extensive plot-derived tree population data from Kibale National Park, Uganda. Changes to this resource landscape are used to simulate effects of anthropogenic forest change. With each change in the landscape, disease outcomes within the simulated red colobus population are monitored using a hypothetical microparasite with a directly transmitted life cycle. The model predicts an optimal distribution of resources which facilitates the spread of an infectious agent through the simulated population. The density of resource rich sites and the overall heterogeneity of the landscape are important factors contributing to this spread. The characteristics of this optimal distribution are similar to those of logged sections of forest adjacent to our study area.     

A community-based approach to low-income residential energy efficiency participation barriers

Financial barriers are often cited as the principle impediment to the adoption of energy efficiency measures. Since 1976, the US Department of Energy's Weatherisation Assistance Programme (WAP) has provided state block grants for no-cost, low-income energy efficiency retrofits. Yet, millions of low-income American households lack affordable, reliable, and efficient energy access. The American Recovery and Reinvestment Act of 2009 boosted WAP's annual appropriation from $230 million to $5 billion, requiring states to explore innovate approaches to quickly increasing programme participation. Community-based energy programmes have shown success for overcoming various barriers and increasing participation in the adoption of energy technologies. This case study explores a community-based approach to scaling WAP-funded energy efficiency retrofits in a cluster of five urban, low-income, majority African-American neighbourhoods, known as the Green Impact Zone (GIZ), in Kansas City, Missouri. Findings from interviews with GIZ stakeholders suggest that local context is important to how energy efficiency participation barriers manifest. The targeted, community-based approach to WAP created institutional capabilities for increased recognition of participation challenges and facilitated opportunities for alternative solutions that may otherwise have been overlooked under the standard self-referral implementation of WAP. Lastly, effective implementation of WAP required policy workarounds that recognised the unique characteristics and needs of the target community.     

Science–policy interactions in Austrian,Dutch, and Swiss climate policy: a comparative account

Scientific expertise plays an important role in the complex field of climate policy. Consequently, science–policy interactions have been institutionalized in many countries. However, science–policy arenas vary considerably across countries. Scholars mainly attribute these differences to the influence of specific political cultures. The literature has primarily compared science–policy arenas of countries with diverging political cultures, whereas comparisons of countries with similar political cultures are rare. The latter is especially true for neo-corporatist cultures. Against this background, we compare the climate science–policy arenas of three neo-corporatist countries, Austria, the Netherlands, and Switzerland. Conceptually, we draw on the literature regarding politico-cultural imprints in science–policy arenas. We operationalize national science–policy arenas along four dimensions: the knowledge actors, the organizational formats, the styles of science–policy interactions, and their transparency and visibility. Overall, the three arenas reveal many similarities and much fewer differences. Most similarities correspond to neo-corporatist patterns. However, some similarities consistently deviate from neo-corporatist patterns. Interestingly, almost all differences between the countries match national variations of neo-corporatism. In light of these observations and the specific problem structure of climate policy, we develop research questions to investigate potential explanations for correspondence to and deviation from neo-corporatist patterns.     

The Missoula Valley semivolatile and volatile organic compound study: seasonal average concentrations

The city of Missoula is located in a high mountain valley (elevation 3200 ft.) in western Montana and contains one of the largest populations in the entire Rocky Mountain Region completely enclosed by mountains. During the 2000/2001 Missoula Valley Sampling Program, ambient levels of 61 semivolatile organic compounds (SVOCs) and 54 volatile organic compounds (VOCs) were originally quantified before refining the analytical program to 28 of the most prominent SVOCs and VOCs found in the Missoula Valley airshed. These compounds were measured over 24-hr periods at two locations throughout an entire year. This study provides the first, comprehensive appraisal of the levels of SVOCs and VOCs measured simultaneously throughout all four seasons at two locations in the Missoula Valley, including those levels measured during the 2000 Montana wildfire season. Generally, SVOC levels were comparable between both sides of the Missoula Valley. However, there were nearly double the amount of VOCs measured at the more urban Boyd Park site compared with the rural Frenchtown sampling site, a result of the greater number of automobiles on the eastern side of the Valley. SVOCs and VOCs were measured at their highest levels of the sampling program during the winter. Forest fire smoke samples collected during the summer of 2000 showed significant increases in SVOC phenolic compounds, including phenol, 2-methylphenol, 4-methylphenol, and 2,4-dimethylphenol. Although there were modest increases in some of the other SVOCs and VOCs measured during the fire season, none of the increases were as dramatic as the phenolics.     

Evaluation of biochemical effects related to perfluorooctane sulfonic acid exposure in organohalogen-contaminated great tit (Parus major) and blue tit (Parus caeruleus) nestlings

A perfluorooctane sulfonic acid (PFOS) biomonitoring survey was conducted on great tit (Parus major) and blue tit (Parus caeruleus) nestlings from Blokkersdijk, a bird reserve in the proximity of a fluorochemical plant in Antwerp (Belgium) and Fort IV, a control area. PFOS, together with 11 organochlorine pesticides, 20 polychlorinated biphenyl congeners and 7 polybrominated diphenyl ethers were measured in liver tissue. The hepatic PFOS concentrations at Blokkersdijk (86–2788 and 317–3322 ng/g wet weight (ww) for great and blue tit, respectively) were among the highest ever measured and were significantly higher than at the control area (17–206 and 69–514 ng/g ww for great and blue tit, respectively). The hepatic PFOS concentration was species- and sex-independent and correlated significantly and positively with the serum alanine aminotransferase activity and negatively with the serum cholesterol and triglyceride levels in both species but did not correlate with condition or serum protein concentration. In the great tit, a significant positive correlation was observed between the liver PFOS concentration and the relative liver weight. In the blue tit, the hepatic PFOS concentration correlated positively and significantly with hematocrite values. None of the investigated organohalogen pollutants except for PFOS were suggested to be involved in the observed biological alterations.     

Perfluorooctane sulfonic acid and organohalogen pollutants in liver of three freshwater fish species in Flanders (Belgium): relationships with biochemical and organismal effects

A perfluorooctane sulfonic acid (PFOS) assessment was conducted on gibel carp (Carassius auratus gibelio), carp (Cyprinus carpio), and eel (Anguilla anguilla) in Flanders (Belgium). The liver PFOS concentrations in fish from the Ieperlee canal (Boezinge, 250-9031 ng/g wet weight, respectively) and the Blokkersdijk pond (Antwerp, 633-1822 ng/g wet weight) were higher than at the Zuun basin (Sint-Pieters-Leeuw, 11.2-162 ng/g wet weight) and among the highest in feral fish worldwide. Eel from the Oude Maas pond (Dilsen-Stokkem) and Watersportbaan basin (Ghent) had PFOS concentrations ranging between 212 and 857 ng/g wet weight. The hepatic PFOS concentration was significantly and positively related with the serum alanine aminotransferase activity, and negatively with the serum protein content in eel and carp. The hepatic PFOS concentration in carp correlated significantly and negatively with the serum electrolyte concentrations whereas a significant positive relation was found with the hematocrit in eel. Although 13 organochlorine pesticides, 22 polychlorinated biphenyl (PCB) congeners and 7 polybrominated diphenyl ethers (PBDEs) were also measured in the liver tissue, only PCB 28, PCB 74, gamma-hexachlorocyclohexane (gamma-HCH) and hexachlorobenzene (HCB) were suggested to contribute to the observed serological alterations in eel.     

Vapor-phase and fine particulate matter concentrations of polycyclic aromatic hydrocarbons measured during the winter months in a northern Rocky Mountain urban airshed

A fine particulate matter (PM2.5) sampling program was conducted in Missoula, MT, to investigate both the particle and vapor phases of PM2.5-associated polycyclic aromatic hydrocarbons (PAHs) found in a northern Rocky Mountain urban airshed. Twenty-four-hour samples were collected during the cold winter months of January through April 2002, when many of the more volatile organic components of PM2.5 were expected to be found in the condensed particle form. To meet analytical detection limits, each of the 12 individual sample days were aggregated into four total filter and polyurethane foam (PUF) samples, respectively, with each aggregate containing 3 sample days. Quartz filter (particle-phase PAHs) and PUF (vapor-phase PAHs) aggregates were analyzed separately for 18 individual PAHs and phenolics by gas chromatography/mass spectrometry. Results showed that 87% of the PM2.5-associated phenolics and PAHs measured in this study were found in the vapor phase. PM2.5-associated gas/particle partition coefficients (Kp,2.5) ranged from 0 for the lighter phenolics and PAHs to approximately 0.1 for some of the heavier PAHs, such as fluoranthene and pyrene. Calculating Kp,2.5 for the heaviest measured PAHs was not feasible because of low or undetectable concentrations in the vapor phases of these compounds. Phenolics and two-ringed and three-ringed PAHs were found almost exclusively in the vapor phase. Four-ringed PAHs were distributed between the particle and vapor phases, with more mass measured in the vapor phase. Very little five-ringed and higher PAHs were measured from either the filter or PUF sampling medium. These results provide information on both the concentrations and different phases of PM2.5-associated PAHs measured during the winter months in a northern Rocky Mountain urban airshed, when concentrations of PM2.5 are generally at their highest compared with the rest of the year.     

Distributed process modeling for regional assessment of coastal vulnerability to sea-level rise

Sea-level rise involves increases in the coastal processes of inundation and erosion which are affected by a complex interplay of physical environmental parameters at the coast. Many assessments of coastal vulnerability to sea-level rise have been detailed and localised in extent. There is a need for regional assessment techniques which identify areas vulnerable to sea-level rise. Four physical environmental parameters – elevation, exposure, aspect and slope, are modeled on a regional scale for the Northern Spencer Gulf (NSG) study area using commonly available low-resolution elevation data of 10 m contour interval and GIS-based spatial modeling techniques. For comparison, the same parameters are modeled on a fine-scale for the False Bay area within the NSG using high-resolution elevation data. Physical environmental parameters on the two scales are statistically compared to coastal vulnerability classes as identified by Harvey et al. [1] using the Spearman rank-correlation test and stepwise linear regression. Coastal vulnerability is strongly correlated with elevation and exposure at both scales and this relationship is only slightly stronger for the high resolution False Bay data. The results of this study suggest that regional scale distributed coastal process modeling may be suitable as a first cut in assessing coastal vulnerability to sea-level rise in tide-dominated, sedimentary coastal regions. Distributed coastal process modeling provides a suitable basis for the assessment of coastal vulnerability to sea-level rise of sufficient accuracy for on-ground management and priority-setting on a regional scale.