Clusters of community exposure to coastal flooding hazards based on storm and sea level rise scenarios—implications for adaptation networks in the San Francisco Bay region

Regional Environmental Change - Sea level is projected to rise over the coming decades, further increasing the extent of flooding hazards in coastal communities. Efforts to address potential...     

Audience segmentation to improve targeting of conservation interventions for hunters

Audience segmentation could help improve the effectiveness of conservation interventions. Marketers use audience segmentation to define the target audience of a campaign. The technique involves subdividing a general population into groups that share similar profiles, such as sociodemographic or behavioral characteristics. Interventions are then designed to target the group or groups of interest. We explored the potential of audience segmentation for use in defining conservation target groups with a case study of hunters in Liberia. Using 2 data sets describing households (n = 476) and hunters (n = 205), we applied a clustering method in which infinite binomial mixture models group hunters and households according to livelihood and behavior variables and a simple method to define target groups based on hunting impact (hunting households and high-impact hunters). Clusters of hunters and households differed in their experiences with confiscation of catch at roadblocks and participation in livelihood-support programs, indicating that these interventions operate unevenly across subsets of the population. By contrast, the simple method masked these insights because profiles of hunting households and high-impact hunters were similar to those of the general population. Clustering results could be used to guide the development of livelihood and regulatory interventions. For example, a commonly promoted agricultural activity, cocoa farming, was practiced by only 2% (out of 87) of the largest hunter cluster of nonlocal gun hunters but was prevalent among local trappers, suggesting that assistance aimed at cocoa farmers is less appropriate for the former group. Our results support the use of audience segmentation across multiple variables to improve targeted intervention designs in conservation.     

Patterns in soil fertility and root herbivory interact to influence fine-root dynamics

Fine-scale soil nutrient enrichment typically stimulates root growth, but it may also increase root herbivory, resulting in trade-offs for plant species and potentially influencing carbon cycling patterns. We used root ingrowth cores to investigate the effects of microsite fertility and root herbivory on root biomass in an aggrading upland forest in the coastal plain of South Carolina, USA. Treatments were randomly assigned to cores from a factorial combination of fertilizer and insecticide. Soil, soil fauna, and roots were removed from the cores at the end of the experiment (8-9 mo), and roots were separated at harvest into three diameter classes. Each diameter class responded differently to fertilizer and insecticide treatments. The finest roots (< 1.0 mm diameter), which comprised well over half of all root biomass, were the only ones to respond significantly to both treatments, increasing when fertilizer and when insecticide were added (each P < 0.0001), with maximum biomass found where the treatments were combined (interaction term significant, P < 0.001). These results suggest that root-feeding insects have a strong influence on root standing crop with stronger herbivore impacts on finer roots and within more fertile microsites. Thus, increased vulnerability to root herbivory is a potentially significant cost of root foraging in nutrient-rich patches.     

Biomonitoring using the lichen Hypogymnia physodes and bark samples near Zlatna, Romania immediately following closure of a copper ore-processing plant

Lichen transplants were established along a 40km transect centred on a large mine waste dump close to Zlatna town centre, two weeks after closure of a major industrial source, to compare spatial patterns of element concentrations in lichen and bark samples. After 3 months of exposure, spatial patterns of 4 element concentrations (Pb, Cu, Zn and Fe) in transplants confirmed deposition due to a point source 'Zlatna influence'. Cu and Pb reached concentrations 8 and 4 times, respectively, higher than samples transplanted in the 'background' site, and over 200 (Cu) and 2000 (Pb) times higher relative to 'background' bark. Ten out of 15 elements analysed reached highest concentrations in bark. Spatial patterns confirmed long-term pollution for 6 elements (Pb, S, Fe, Cu, Zn and Ba). The study provides a model baseline to monitor recovery following closure of major industrial sources and highlights the importance of considering biogeochemical processes when interpreting metal concentrations.     

Evaluation of performance reference compounds in polyethylene-based passive air samplers

Polyethylene-based passive air samplers (PSDs) were loaded with performance reference compounds (PRCs) and deployed in a wind tunnel to examine the effects of wind speed on sampler performance. PRCs could be loaded reproducibly into PSDs, with coefficients of variation only exceeding 20% for the more volatile compounds. When PSDs were exposed to low (0.5-1.5 m s-1) and high (3.5-4.5 m s-1) wind speeds, PRC loss rate constants generally increased with increasing wind speed and decreased with increasing sampler/air partition coefficients. PSD-based air concentrations calculated using PRC loss rate constants and sampler/air partition coefficients and air concentrations measured using active samplers compared closely. PRCs can be used to account for the effect of differences in wind speeds on sampler performance and measure air concentrations with reasonable accuracy.     

Detecting changes in insect herbivore communities along a pollution gradient

The forests surrounding the urban areas of the Los Angeles basin are impacted by ozone and nitrogen pollutants arising from urban areas. We examined changes in the herbivore communities of three prominent plant species (ponderosa pine, California black oak and bracken fern) at six sites along an air pollution gradient. Insects were extracted from foliage samples collected in spring, as foliage reached full expansion. Community differences were evaluated using total herbivore abundance, richness, Shannon-Weiner diversity, and discriminant function analysis. Even without conspicuous changes in total numbers, diversity or richness of herbivores, herbivore groups showed patterns of change that followed the air pollution gradient that were apparent through discriminant function analysis. For bracken fern and oak, chewing insects were more dominant at high pollution sites. Oak herbivore communities showed the strongest effect. These changes in herbivore communities may affect nutrient cycling in forest systems.     

Analysis of Mosses and Soils for Quantifying Heavy Metal Concentrations in Sicily: A Multivariate and Spatial Analytical Approach

- DOI: http://dx.doi.org/10.1065/espr2006.01.006 Background The use of vegetal organisms as indicators of contamination of the environment is partially replacing traditional monitoring techniques. Amongst the vegetal organisms available, mosses appear to be good bioindicators and are used for monitoring anthropogenic and natural fall-out on soils. This study has two objectives: the evaluation of the concentrations of heavy metals in soils and mosses of the Sicily Region, in Italy and the identification of the origin of fall-out of heavy metals. Methods Mosses and the surface soil were sampled at 28 sites, only the youngest segments of Hylocomium splendens and Hypnum cupressiforme, corresponding to the plant tissues produced during the last 3 years, were taken. The elements Cd, Cu, Ni, Pb and Zn were analysed by ICP-MS and Hg by AAS. Statistical analysis was by PCA and spatial representation by GIS. Results and Discussion In the mosses sampled in Sicily, the highest concentrations of Cd were found around the cities of Palermo and Messina. The highest concentrations of Hg were recorded in the northern part of the island between Trapani and Messina, similar to the distribution of Cu. Different areas with the highest concentrations of Ni were found near the south coast, in the vicinity of Palermo and around the Volcano Etna. The highest concentrations of Pb were found in the south-west coast near Agrigento, where important chemical plants and petroleum refineries are located. Except for a few locations, Zn fall-out was found to be evenly distributed throughout Sicily. Conclusion The sites where the concentrations of heavy metals cause greatest concern have been revealed by the PCA analysis and portrayed using GIS. Also of some concern is the diffuse and anthropogenic origin of Hg and Cd. The combined approach of using soil and mosses, together with pedological interpretation and application of multivariate statistical techniques has provided valuable insight into the environmental aspects of heavy metal deposition in a region of southern Europe. Recommendations and Outlook Further insight into the deposition of heavy metals will require more detailed sampling of soils and mosses in both new and previous study areas. This needs to be complemented by detailed pedological investigations in the study areas. Future research programmes will address these issues.     

Thermoplastic Blends from Albumin and Zein: Plastic Formation and Mechanical Properties Including Modeling

The use of proteins in blending with traditional polymers in the formation of thermoplastics can produce plastics with properties that are superior to traditional petroleum-based plastics. We investigated the physical and thermal properties of albumin and zein thermoplastic blends plasticized with glycerol and mixed with varying amounts of low-density polyethylene (LDPE). Several mechanical models were utilized to determine how tensile properties will be altered when varying amounts of protein/LDPE were added into the thermoplastic blend. When analyzed for thermal properties, we found that as the amount of LDPE in the thermoplastic blend increased, the resulting plastic possessed thermal properties that were more similar to pure LDPE plastics. In terms of mechanical properties, comparison between the experimental data and model predictions points to a synergistic effect between albumin and LDPE that leads to higher modulus, while a potential lack of compatibility between zein and LDPE leads to a plastic with lower modulus. Based on our results, the use of albumin and zein proteins when blended with LDPE in the production of thermoplastics has potential use in the areas of medical and food packaging applications.     

Selfing in <Emphasis Type="Italic">Parvulastra exigua</Emphasis>: an asterinid sea star with benthic development

Parvulastra exigua, a species that lacks a dispersive larva, is paradoxically one of the most widely distributed and abundant sea stars in Australia. The potential that self-fertilization and successful development of self-generated progeny might contribute to population maintenance in this species was investigated through induction of spawning in isolated individuals collected from five populations near Sydney, New South Wales (34°S, 151°E), during the spawning period (August–October 2010, 2011). Evidence of selfing differed significantly among the five populations but the level of selfing within individual egg masses did not. Overall, there was a mean of 8.9% fertilization in egg masses with embryos. Some clutches developed to the juvenile stage while others arrested development before hatching. The presence of miniscule testis tissue in gonads that appeared to be ovaries indicated that hermaphroditism may be more common in some populations than indicated by anatomy. Mixed mating (selfing + outcrossing), pseudocopulation during egg laying and developmental success of self-fertilized embryos may contribute to the ecological success of P. exigua. These might influence population genetic structure and would facilitate establishment of founder populations by a small number of migrants.