Putting vulnerability to climate change on the map: a review of approaches, benefits, and risks

There is growing demand among stakeholders across public and private institutions for spatially-explicit information regarding vulnerability to climate change at the local scale. However, the challenges associated with mapping the geography of climate change vulnerability are non-trivial, both conceptually and technically, suggesting the need for more critical evaluation of this practice. Here, we review climate change vulnerability mapping in the context of four key questions that are fundamental to assessment design. First, what are the goals of the assessment? A review of published assessments yields a range of objective statements that emphasize problem orientation or decision-making about adaptation actions. Second, how is the assessment of vulnerability framed? Assessments vary with respect to what values are assessed (vulnerability of what) and the underlying determinants of vulnerability that are considered (vulnerability to what). The selected frame ultimately influences perceptions of the primary driving forces of vulnerability as well as preferences regarding management alternatives. Third, what are the technical methods by which an assessment is conducted? The integration of vulnerability determinants into a common map remains an emergent and subjective practice associated with a number of methodological challenges. Fourth, who participates in the assessment and how will it be used to facilitate change? Assessments are often conducted under the auspices of benefiting stakeholders, yet many lack direct engagement with stakeholders. Each of these questions is reviewed in turn by drawing on an illustrative set of 45 vulnerability mapping studies appearing in the literature. A number of pathways for placing vulnerability mapping on a more robust footing are also identified.     

UV-B exposure increases acute toxicity of pentachlorophenol and mercury to the rotifer Brachionus calyciflorus

Adverse biological effects of ultraviolet-B (UV-B) radiation have been well documented for phytoplankton and zooplankton in both marine and freshwater ecosystems. However, investigations of interactions between UV-B and anthropogenic toxicants have focused primarily on the chemical interactions between UV-B and the toxicant. Here we investigate the potential for UV-B to increase the sensitivity of the rotifer Brachionus calyciflorus to either acute pentachlorophenol (PCP) or mercury toxicity, independent of UV-B effects on these toxicants. UV-B increased the toxicity of PCP and mercury to B. calyciflorus as much as five-fold, depending on duration of UV-B exposure and toxicant concentration. Reductions in the LC(50) of up to 60% were also seen for both toxicants. UV-B alone effectively eliminated B. calyciflorus reproduction and reduced ingestion by up to 90%. These results demonstrate the potential for UV-B to increase rotifer sensitivity to anthropogenic stressors independent of photochemical reactions with toxicants.     

The interactions of phthalate esters with suspended particulate material in fresh and marine waters

The behaviour of six phthalate esters in the presence of particulate material suspended in fresh and saline water has been examined. The adsorption of all phthalates by the particulates is enhanced by the presence of salt. The adsorption process is fairly rapid ( <2-3 h) and the degree of adsorption depends on the characteristics of the particulates. Di-ethylhexyl phthalate is adsorbed most actively by material of a small particle size. The adsorption of other phthalates is more strongly influenced by the chemical composition of the particulates and is most closely correlated with their lipid content.     

Atmospheric vapour phase and particulate phase mercury in a coastal desert climate

Vapour (T-Hg(v)) and particulate (T-Hg(p)) mercury were measured in the lower atmosphere at a ground station in Kuwait Bay. The concentration of T-Hg(v) varied from 0-86 ng m(-3) with a mean of 3.8 +/- 5.5 ng m(-3)(n= 13 326). About 40% of the measured T-Hg(v) values over Kuwait Bay are higher than the global range (1-3 ng m(-3)). Car exhausts contributed to the increase of T-Hg(v) during the rush hours. However the contribution of T-Hg(v) from air crossing Kuwait Bay exceeds that T-Hg(v) produced by traffic probably because of the effects of the substantial load of industrially-derived mercury in the sediments of this shallow region. Thermal inversions have a major impact on the levels during the evening hours. The concentration of T-Hg(p) varied from 0.00-0.22 ng m(-3) with a mean of 0.03 +/- 0.03 ng m(-3)(n= 175). The T-Hg(p)/T-Hg(v)% ratio varied from 0-11.1 (n= 171) with a mean of 1.0 +/- 1.5%. Meteorological parameters influence the T-Hg(v) and T-Hg(p) concentrations with dust storms having a major impact on T-Hg(p) concentrations.     

Soil solution extraction techniques for microbial ecotoxicity testing: a comparative evaluation

The suitability of two different techniques (centrifugation and Rhizon sampler) for obtaining the interstitial pore water of soil (soil solution), integral to the ecotoxicity assessment of metal contaminated soil, were investigated by combining chemical analyses and a luminescence-based microbial biosensor. Two different techniques, centrifugation and Rhizon sampler, were used to extract the soil solution from Insch (a loamy sand) and Boyndie (a sandy loam) soils, which had been amended with different concentrations of Zn and Cd. The concentrations of dissolved organic carbon (DOC), major anions (F- , CI-, NO3, SO4(2-)) and major cations (K+, Mg2+, Ca2+) in the soil solutions varied depending on the extraction technique used. Overall, the concentrations of Zn and Cd were significantly higher in the soil solution extracted using the centrifugation technique compared with that extracted using the Rhizon sampler technique. Furthermore, the differences observed between the two extraction techniques depended on the type of soil from which the solution was being extracted. The luminescence-based biosensor Escherichia coli HB101 pUCD607 was shown to respond to the free metal concentrations in the soil solutions and showed that different toxicities were associated with each soil, depending on the technique used to extract the soil solution. This study highlights the need to characterise the type of extraction technique used to obtain the soil solution for ecotoxicity testing in order that a representative ecotoxicity assessment can be carried out.     

Analysis of ambient,precipitation-weighted,and lake sulfate concentrations in the Adirondack region of New York

AbstractIt is well known that many ecosystems in the eastern United States, including the Adirondack Mountain region of New York, are particularly sensitive to acidic deposition because the soils and lakes in the region tend to have low values of base saturation and acid neutralizing capacity, respectively [e.g. Environ Sci Policy, 1 (1998), 185]. To facilitate tracking the impacts of anthropogenic emissions on air quality, acidic deposition, and surface water quality, the National Atmospheric Deposition Program, New York State Department of Environmental Conservation, and Adirondack Lake Survey Corporation have been monitoring ambient sulfur dioxide and aerosol sulfate levels, and anion and cation concentrations in wet deposition and lake water over the past few decades. In this paper, we discuss the seasonality and year-to-year variability, and illustrate some of the complexities in estimating temporal trends in these data. The periods of analysis extended through 2000, beginning in 1991 for the ambient air quality data, 1978 for the wet deposition data, and 1982 for the lake water quality data. While the lake water SO4(2-) concentrations appear to be decreasing gradually, the air concentration data appear to have changed abruptly in the 1990s and the precipitation-weighted concentrations exhibited both gradual and sharp decreases during the same period.     

Coupled effects of solution chemistry and hydrodynamics on the mobility and transport of quantum dot nanomaterials in the vadose zone

To investigate the coupled effects of solution chemistry and hydrodynamics on the mobility of quantum dot (QD) nanoparticles in the vadose zone, laboratory scale transport experiments involving single and/or sequential infiltrations of QDs in unsaturated and saturated porous media, and computations of total interaction and capillary potential energies were performed. As ionic strength increased, QD retention in the unsaturated porous media increased; however, this retention was significantly suppressed in the presence of a non-ionic surfactant in the infiltration suspensions as indicated by surfactant enhanced transport of QDs. In the vadose zone, the non-ionic surfactant limited the formation of QD aggregates, enhanced QD mobility and transport, and lowered the solution surface tension, which resulted in a decrease in capillary forces that not only led to a reduction in the removal of QDs, but also impacted the vadose zone flow processes. When chemical transport conditions were favorable (ionic strength of 5 × 10(-4)M and 5 × 10(-3)M, or ionic strengths of 5 × 10(-2)M and 0.5M with surfactant), the dominating phenomena controlling the mobility and transport of QDs in the vadose zone were meso-scale processes, where infiltration by preferential flow results in the rapid transport of QDs. When chemical transport conditions were unfavorable (ionic strength of 5 × 10(-2)M and 0.5M) the dominating phenomena controlling the mobility and transport of QDs in the vadose zone were pore-scale processes governed by gas-water interfaces (GWI) that impact the mobility of QDs. The addition of surfactant enhanced the transport of QDs both in favorable and unfavorable chemical transport conditions. The mobility and retention of QDs was controlled by interaction and capillary forces, with the latter being the most influential. GWI were found to be the dominant mechanism and site for QD removal compared with solid-water interfaces (SWI) and pore straining. Additionally, ripening phenomena were demonstrated to enhance QDs removal or retention in porous media and to be attenuated by the presence of surfactant.     

Post-rehabilitation environmental hazard of Cu, Zn, As and Pb at the derelict Conrad Mine, eastern Australia

A post-rehabilitation audit of the derelict Conrad base metal mine, eastern Australia, indicates ongoing environmental hazard regarding acid mine drainage and concentrations of arsenic and lead to 3 wt% in the soil and sediment. In order to rehabilitate remote contaminated sites effectively, on-site analyses should be carried out to ensure that the materials used to rehabilitate the site are not contaminant-bearing. Understanding the geomorphic setting of the rehabilitated areas is also important in understanding where, and for what period, contaminated materials might be stored in fluvial systems downstream of mine workings. Chemical and geomorphic audits should form a fundamental part of all rehabilitation works to ensure favourable environmental outcomes.     

Harvesting and climate effects on organic matter characteristics in British Columbia coastal forests

As part of investigations into the effects of harvesting old-growth forest, we characterized carbon in five organic matter pools in eight forest chronosequences of coastal British Columbia. Each chronosequence comprised stands in four seral stages from regeneration (3-8 yr) to old-growth (>250 yr), with second-growth stands mostly of harvest origin. Stands were located in two biogeoclimatic subzones with contrasting climate (wetter, slightly cooler conditions on the west coast of Vancouver Island than on the east). Carbon concentrations in fine woody debris (FWD), forest floor (LFH), fine roots from LFH, and two water-floatable fractions from 10 to 30 cm mineral soil (MIN-ROOT, 2-8 mm and MIN-FLOAT, <2 mm) showed no significant effects due to climate, seral stage, or site. There were some significant differences in N concentrations, but none related to seral stage. Carbon-13 cross-polarization with magic-angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectra with principal component analysis of relative areas also showed little harvesting effect, but greater variation related to input of coarse woody debris (CWD) vs. roots high in tannin. Overall, there tended to be more spectral features associated with wood and lignin in the west; whereas some MIN-ROOT samples from the drier east side had aromatic intensity attributed to charcoal. The minimal effects of one harvest on organic matter are most likely due to the large legacy effect; however, more intensive management will probably result in less CWD retention, less charcoal input, and less microsite variability in these pools of poorly decomposed organic matter.     

Identifying source correlation parameters for hydrocarbon wastes using compound-specific isotope analysis

A preliminary evaluation of compound-specific isotope analysis (CSIA) as a novel, alternative method for identifying source correlation compounds in soils contaminated with residual heavy or weathered petroleum wastes is presented. Oil-contaminated soil microcosms were established using soil (sandy-loam, non-carbonaceous cley) amended with ballast-, crude- or No.6 fuel oil. Microcosms were periodically sampled over 256 days and delta(13)C values (which express the ratio of (13)C to (12)C) determined at each time point for five n-alkanes and the isoprenoid norpristane using gas chromatography-isotope ratio mass spectrometry (GC-IRMS). Although some temporal variation was observed, no significant temporal shifts in the delta(13)C values for the five n-alkanes were measured in all three oils. Isoprenoid isotope ratios (delta(13)C) appeared to be least affected by biotransformation, especially in the No.6 fuel oil. The research suggests that the delta(13)C of isoprenoids such as norpristane, may be of use as source correlation parameters.