Risk perception and trust in the context of urban brownfields

Data are reported from a postal questionnaire completed by 747 residents of two urban local authority areas within which there were sites of brownfield land with significant levels of contamination. Respondents rated their perceptions of the extent to which their neighbourhood and own home were relatively vulnerable to contamination, their concern about possible effects of contamination, their satisfaction with their council in terms of consultation with residents on housing and development issues, and their trust in their council with respect to contaminated land risks. Satisfaction with, and trust in, the council was generally low in both areas, and especially so among those who perceived themselves to be more vulnerable to contamination. Nonetheless, dissatisfaction was less marked in the area where the local authority, according to background information, had pursued a more open and proactive style of risk communication and consultation with residents. The main predictors of trust, across both areas, were perceptions that the council was openly prepared to tell residents what they knew, and that the council had residents' interests at heart. Implications are discussed for the impact of different modes of risk communication on trust.     

Genetic mating system of the brown smoothhound shark (<Emphasis Type="Italic">Mustelus henlei</Emphasis>), including a literature review of multiple paternity in other elasmobranch species

Although an understanding of mating systems is thought to be an important component of long-term population management, these life history characteristics are poorly known in sharks. Here, we employ polymorphic microsatellite markers to test for the occurrence and prevalence of multiple paternity in a population of the brown smoothhound shark, Mustelus henlei. We analyzed litters from 14 females sampled from the Pacific coast of Baja California Sur. The minimum number of sires ranged from one to three with an average of 2.3 sires per litter. Regression analyses did not indicate a relationship between female body size and number of sires, or female body size and size of the litter. A review of the existing literature on genetic mating systems in sharks suggests that polyandry may be common and that reproductive behavior may have evolved from conflicting selection pressures between the sexes.     

Role of climate and competitors in limiting fitness across range edges of an annual plant

It is often assumed that the geographic distributions of species match their climatic tolerances, but this assumption is not frequently tested. Moreover, few studies examine the relative importance of abiotic and biotic factors for limiting species ranges. We combined multiple approaches to assess the extent to which fitness of a widespread native annual legume, Chamaecrista fasciculata, decreases at and beyond its northern and western range edges, and how this is influenced by the presence of neighbors. First, we examined plant fitness and the effect of neighbors in natural populations at different geographic range locations for three years. Fitness decreased toward the northern range edge, but not the western edge. Neighbor removal had a consistently positive effect on seedpod production across all years and sites. Second, we established experimental populations at sites within the range, and at and beyond the northern and western range edges. We tracked individual fitness and recorded seedling recruitment in the following year (a complete generation) to estimate population growth rate. Individual fitness and population growth declined to near zero beyond both range edges, indicating that C. fasciculata with its present genetic composition will not establish in these regions, given conditions currently. We also carried out a neighbor removal treatment. Consistent with the natural populations, neighbors reduced seedpod production of reproductive adults. However, neighbors also increased early-season survival, and this positive effect early in life history resulted in a net positive effect of neighbors on lifetime fitness at most range locations. Our data show that the population growth rate of C. fasciculata includes values above replacement, and populations are well adapted to conditions up to the edge of the range, whereas the severely compromised fitness at sites beyond the edge precludes immediate establishment of populations and thereby impedes adaptation to these conditions.     

Evolution, radiation and chemotaxonomy of Lamellodysidea, a demosponge genus with anti-plasmodial metabolites

Sponges of the family Dysideidae (Dictyoceratida) are renowned for their diversity of secondary metabolites, and its genus Lamellodysidea, particularly Lamellodysidea herbacea, is the most studied taxon biochemically. Despite its importance, the taxonomic status of L. herbacea—whether it is a distinct species or a species complex—has never been assessed. Recent biochemical profiling revealed anti-plasmodial activity of brominated compounds in Lamellodysidea of the Pacific. Here, we present a comparative chemotaxonomic and molecular analysis of selected Dysideidae from the Pacific and the Indian Ocean (New Caledonia, Great Barrier Reef, Fiji, Mayotte, Guam, Palau). We investigated the phylogenetic relationships between the populations and assessed their bioactive (PBDE) compounds in order to unravel the taxonomic status of this commercially important group of sponges and assessed patterns of dispersal and biochemical variation. The molecular phylogeny was based on the internal transcribed ribosomal spacer and compared against a PBDE phylogeny for several specimens. Molecular data revealed a diversity of Indo-Pacific L. herbacea populations, also reflected by different PBDE compound profiles. Molecular and biochemical data also revealed a Lamellodysidea species new to science. Several specimens misidentified as Lamellodysidea were detected based on their position on different clades in the molecular phylogeny and their production of different halogenated compounds (brominated vs. chlorinated). The direct comparison of molecular and biochemical data also provided evidence for the occurrence of a host switch event and support for the theory that abiotic factors, such as sedimentation, affect the chemical constituents produced in L. herbacea.     

In situ rates of body growth and palp regeneration of a spionid polychaete following simulated sublethal predation

Sublethal predation can be a significant trophic pathway in sediment communities, and the regeneration of damaged tissue affects the activity, growth, and reproduction of prey. A field experiment was conducted 12–18 July 2010 in the Tijuana Estuary, California (+32.56617°, −117.13152°), to measure in situ rates of body growth and palp regeneration of the polychaete Polydora cornuta after simulating sublethal predation by removing 2, 1, or 0 palps from labeled individuals. After 3 days in the field, individuals that had 2 palps removed grew significantly slower than worms that had 0 palps removed; 1-palp worms had intermediate growth. After 6 days in the field, rates of body growth were faster than those of worms recovered after 3 days, with similar trends among the three palp treatments. During the 3-day transplantation, removed palps regenerated to half the initial length of unmanipulated palps. After 6 days, palp lengths did not differ significantly among treatment groups, indicating complete regeneration. The regeneration rate of removed palps was significantly faster than the growth rate of undamaged palps, and palp regeneration rate did not differ significantly between worms that had 1 or 2 palps removed.     

Height-growth response to climatic changes differs among populations of Douglas-fir: a novel analysis of historic data

Projected climate change will affect existing forests, as substantial changes are predicted to occur during their life spans. Species that have ample intraspecific genetic differentiation, such as Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), are expected to display population-specific growth responses to climate change. Using a mixed-effects modeling approach, we describe three-year height (HT) growth response to changes in climate of interior Douglas-fir populations. We incorporate climate information at the population level, yielding a model that is specific to both species and population. We use data from provenance tests from previous studies that comprised 236 populations from Idaho, Montana, and eastern Washington, USA. The most sensitive indicator of climate was the mean temperature of the coldest month. Population maximum HT and HT growth response to changes in climate were dependent on seed source climate. All populations had optimum HT growth when transferred to climates with warmer winters; those originating in sites with the warmest winters were taller across sites and had highest HT growth at transfer distances closest to zero; those from colder climates were shortest and had optimum HT growth when transferred the farthest. Although this differential response damped the height growth differences among populations, cold-climate populations still achieved their maximum growth at lower temperatures than warm-climate populations. The results highlight the relevance of understanding climate change impacts at the population level, particularly in a species with ample genetic variation among populations.     

Business recovery: an assessment framework

This paper presents a Business Recovery Assessment Framework (BRAF) to help researchers and practitioners design robust, repeatable, and comparable studies of business recovery in various post‐disruption contexts. Studies assessing business recovery without adequately considering the research aims, recovery definitions, and indicators can produce misleading findings. The BRAF is composed of a series of steps that guide the decisions that researchers need to make to ensure: (i) that recovery is indeed being measured; (ii) that the indicators of recovery that are selected align with the objectives of the study and the definition of recovery; and, where necessary, (iii) that appropriate comparative control variables are in place. The paper draws on a large dataset of business surveys collected following the earthquakes in Canterbury, New Zealand, on 4 September 2010 and 22 February 2011 to demonstrate the varied conclusions that different recovery indicators can produce and to justify the need for a systematic approach to business recovery assessments.     

Post-larval development of two intertidal barnacles at elevated CO2 and temperature

Ocean acidification and global warming are occurring concomitantly, yet few studies have investigated how organisms will respond to increases in both temperature and CO₂. Intertidal microcosms were used to examine growth, shell mineralogy and survival of two intertidal barnacle post-larvae, Semibalanus balanoides and Elminius modestus, at two temperatures (14 and 19°C) and two CO₂ concentrations (380 and 1,000 ppm), fed with a mixed diatom-flagellate diet at 15,000 cells ml⁻¹ with flow rate of 10 ml⁻¹ min⁻¹. Control growth rates, using operculum diameter, were 14 ± 8 μm day⁻¹ and 6 ± 2 μm day⁻¹ for S. balanoides and E. modestus, respectively. Subtle, but significant decreases in E. modestus growth rate were observed in high CO₂ but there were no impacts on shell calcium content and survival by either elevated temperature or CO₂. S. balanoides exhibited no clear alterations in growth rate but did show a large reduction in shell calcium content and survival under elevated temperature and CO₂. These results suggest that a decrease by 0.4 pH_(NBS) units alone would not be sufficient to directly impact the survival of barnacles during the first month post-settlement. However, in conjunction with a 4–5°C increase in temperature, it appears that significant changes to the biology of these organisms will ensue.     

Counterintuitive effects of large-scale predator removal on a midlatitude rodent community

Historically, small mammals have been focal organisms for studying predator-prey dynamics, principally because of interest in explaining the drivers of the cyclical dynamics exhibited by northern vole, lemming, and hare populations. However, many small-mammal species occur at relatively low and fairly stable densities at temperate latitudes, and our understanding of how complex predator assemblages influence the abundance and dynamics of these species is surprisingly limited. In an intact grassland ecosystem in western Montana, USA, we examined the abundance and dynamics of Columbian ground squirrels (Spermophilus columbianus), deer mice (Peromyscus maniculatus), and montane voles (Microtus montanus) on 1-ha plots where we excluded mammalian and avian predators and ungulates, excluded ungulates alone, or allowed predators and ungulates full access. Our goal was to determine whether the relatively low population abundance and moderate population fluctuations of these rodents were due to population suppression by predators. Our predator-exclusion treatment was divided into two phases: a phase where we excluded all predators except weasels (Mustela spp.; 2002-2005), and a phase where all predators including weasels were excluded (2006-2009). Across the entire duration of the experiment, predator and/or ungulate exclusion had no effect on the abundance or overall dynamics of ground squirrels and deer mice. Ground squirrel survival (the only species abundant enough to accurately estimate survival) was also unaffected by our experimental treatments. Prior to weasel exclusion, predators also had no impacts on montane vole abundance or dynamics. However, after weasel exclusion, vole populations reached greater population peaks, and there was greater recruitment of young animals on predator-exclusion plots compared to plots open to predators during peak years. These results suggest that the impacts of predators cannot be generalized across all rodents in an assemblage. Furthermore, they suggest that specialist predators can play an important role in suppressing vole abundance even in lower-latitude vole populations that occur at relatively low densities.     

Sea level rise and eelgrass (Zostera marina) production: A spatially explicit relative elevation model for Padilla Bay, WA

The dynamics that govern the elevation of a coastal wetland relative to sea level are complex, involving non-linear feedbacks among opposing processes. Changes in the balance between these processes can result in significant alterations to vegetation communities that are adapted to a specific range of water levels. Given that current sedimentation rates in Padilla Bay, Washington are likely less than historical levels and that eustatic sea level rise is accelerating, the extensive Zostera marina (eelgrass) meadows in the bay may be at risk of eventual submergence. We developed a spatially explicit relative elevation model and used it to project changes in the productivity and distribution of eelgrass in Padilla Bay over the next century. The model is mechanistic and incorporates many of the processes and feedbacks that govern coastal wetland elevation change. Accretion estimates made using ²¹⁰Pb dating of sediment cores, sediment characteristics measured within cores, and eelgrass productivity and decomposition data were used to initialize and calibrate the model. Validation was performed using an elevation change rate measured with a network of surface elevation tables. Both the field data and model simulations revealed a net accretion deficit for the bay. Simulations using current rates of sea level rise indicated an overall expansion of eelgrass within Padilla Bay over the next century as it migrates from the center of the bay shoreward.