Transformative climate change adaptation: bridging existing approaches with post-foundational insights on justice

ABSTRACT

Climate adaptation is a complex policy domain, spanning multiple sectors, scales and actors, and wherein those most at risk have the least power. The influence of linear positivist models of science uptake are proving ineffective in a world with increasingly concentrated wealth and power, institutional barriers, and rapidly growing risks facing the many. A plurality of approaches is needed to better examine those dynamics of climate adaptation which are often invisible in models of science uptake – equity, the value of contestation, path dependency – and to consider how to empower communities to find solutions. In this conceptual paper, we argue that bridging existing positivist and interpretivist methods with insights from post-foundational theory so as to underpin pluralism and re-orient ethical principles of justice, strengthens the capacity of social research to support transformative climate adaptation. Principles are proposed to facilitate such bridging.     

Spatially distributed modeling of the long-term carbon balance of a boreal landscape

Spatially and temporally distributed information on the sizes of biomass carbon (C) pools (BCPs) and soil C pools (SCPs) is vital for improving our understanding of biosphere-atmosphere C fluxes. Because the sizes of C pools result from the integrated effects of primary production, age-effects, changes in climate, atmospheric CO₂ concentration, N deposition, and disturbances, a modeling scheme that interactively considers these processes is important. We used the InTEC model, driven by various spatio-temporal datasets to simulate the long-term C-balance in a boreal landscape in eastern Canada. Our results suggested that in this boreal landscape, mature coniferous stands had stabilized their productivity and fluctuated as a weak C-sink or C-source depending on the interannual variations in hydrometeorological factors. Disturbed deciduous stands were larger C-sinks (NEP₂₀₀₄ = 150 gC m⁻² yr⁻¹) than undisturbed coniferous stands (e.g. NEP₂₀₀₄ = 8 gC m⁻² yr⁻¹). Wetlands had lower NPP but showed temporally consistent C accumulation patterns. The simulated spatio-temporal patterns of BCPs and SCPs were unique and reflected the integrated effects of climate, plant growth and atmospheric chemistry besides the inherent properties of the C pool themselves. The simulated BCPs and SCPs generally compared well with the biometric estimates (BCPs: r = 0.86, SCPs: r = 0.84). The largest BCP biases were found in recently disturbed stands and the largest SCP biases were seen in locations where moss necro-masses were abundant. Reconstructing C pools and C fluxes in the ecosystem in such a spatio-temporal manner could help reduce the uncertainties in our understanding of terrestrial C-cycle.     

Anticoagulant rodenticide exposure in raptors from Ontario,Canada

Environmental Science and Pollution Research - Anticoagulant rodenticides (ARs) are used globally to control rodent pest infestations in both urban and agricultural settings. It is well documented...     

Mitochondrial DNA and electronic tracking reveal population structure of Atlantic bluefin tuna (Thunnus thynnus)

Population subdivision was examined in Atlantic bluefin tuna (Thunnus thynnus) through sequencing of the control region of the mitochondrial genome. A total of 178 samples from the spawning grounds in the Gulf of Mexico, Bahamas and Mediterranean Sea were analyzed. Among the samples from these locations were 36 electronically tagged bluefin tuna that were tagged in the North Atlantic and subsequently traveled to one of these known spawning grounds during the spawning season. Bluefin tuna populations from the Gulf of Mexico and the Mediterranean Sea were found to be genetically distinct based on Φ_st, and sequence nearest neighbor analyses, showing that these two major spawning areas support independent stocks. Sequence nearest neighbor analysis indicated significant population subdivision among the Gulf of Mexico, western Mediterranean and eastern Mediterranean Sea. However, it was not possible to find significant pairwise differences between any sampling areas when using all samples. If only samples that had a high likelihood of assignment to a specific spawning site were used (young of the year, spawning adults), the differentiation increased among all sampling areas and the Western Mediterranean Sea was distinct from the Eastern Mediterranean Sea and the Gulf of Mexico. It was not possible to distinguish samples from the Bahamas from those collected at any of the other sampling sites. These data support tagging results that suggested distinctness of the Gulf of Mexico, Eastern and Western Mediterranean Sea spawning areas. This level of stock differentiation is only possible if Atlantic bluefin tuna show strong natal homing to individual spawning grounds.     

Strong variability in bacterioplankton abundance and production in central and western Bay of Bengal

With large influx of freshwater that decreases sea-surface salinities, weak wind forcing of <10 m s⁻¹ and almost always warm (>28°C) sea-surface temperature that stratifies and shallows the mixed layer leading to low or no nutrient injections into the surface, primary production in Bay of Bengal is reportedly low. As a consequence, the Bay of Bengal is considered as a region of low biological productivity. Along with many biological parameters, bacterioplankton abundance and production were measured in the Bay of Bengal during post monsoon (September–October 2002) along an open ocean transect, in the central Bay (CB, 88°E) and the other transect in the western Bay (WB). The latter representing the coastal influenced shelf/slope waters. Bacterioplankton abundances (<2 × 10⁹cells l⁻¹) were similar to those reported from the HNLC equatorial Pacific and the highly productive northern Arabian Sea. Yet, the thymidine uptake rates along CB (average of 1.46 pM h⁻¹) and WB (average of 1.40 pM h⁻¹) were less than those from the northwestern Indian Ocean. These abundances and uptake rates were higher than those in the oligotrophic northwestern Sargasso Sea (<7 × 10⁸ cells l⁻¹; av 1.0 pM h⁻¹). Concentrations of chlorophyll a (chl a), primary production rates and total organic carbon (TOC) were also measured for a comparison of heterotrophic and autotrophic production. In the WB, bacterioplankton carbon biomass equaled ∼ 95% of chl a carbon than just 31% in the CB. Average bacterial:primary production (BP:PP) ratios accounted for 29% in the CB and 31% in the WB. This is mainly due to lower primary productivity (PP) in the WB (281 mg C m⁻² d⁻¹) than in the CB (306 mg C m⁻² day⁻¹). This study indicates that bacteria–phytoplankton relationship differs in the open (CB) and coastal waters (WB). Higher abundance and contrastingly low bacterial production (BP) in WB may be because of the riverine bacteria, brought in through discharges, becoming dormant and unable to reproduce in salinities of 28 or more psu. Heterotrophic bacteria appear to utilize in situ DOC rather rapidly and their carbon demand is ∼50% of daily primary production. It is also apparent that allochthonous organic matter, in particular in the western Bay, is important for meeting their carbon demand.     

Does the risk of encountering lions influence African herbivore behaviour at waterholes?

A central question in the study of predator–prey relationships is to what extent prey behaviour is determined by avoidance of predators. Here, we test whether the long-term risk of encountering lions and the presence of lions in the vicinity influence the behaviour of large African herbivores at waterholes through avoidance of high-risk areas, increases in group size, changes in temporal niche or changes in the time spent in waterhole areas. In Hwange National Park, Zimbabwe, we monitored waterholes to study the behaviour of nine herbivore species under different risks of encountering lions. We radio-collared 26 lions in the study area which provided the opportunity to monitor whether lions were present during observation sessions and to map longer-term seasonal landscapes of risk of encountering lions. Our results show that the preferred prey species for lions (buffalo, kudu and giraffe) avoided risky waterholes. Group size increased as encounter risk increased for only two species (wildebeest and zebra), but this effect was not strong. Interestingly, buffalo avoided the hours of the day which are dangerous when the long-term and short-term risks of encountering lions were high, and all species showed avoidance of waterhole use at night times when lions were in the vicinity. This illustrates well how prey can make temporal adjustments to avoid dangerous periods coinciding with predator hunting. Additionally, many herbivores spent more time accessing water to drink when the long- and short-term risks of encountering lions were high, and they showed longer potential drinking time when the long-term risk of encountering lions was high, suggesting higher levels of vigilance. This study illustrates the diversity of behavioural adjustments to the risk of encountering a predator and how prey respond differently to temporal variations in this risk.     

Relationships between species richness, evenness, and abundance in a southwestern savanna

Species richness and evenness are components of biological diversity that may or may not be correlated with one another and with patterns of species abundance. We compared these attributes among flowering plants, grasshoppers, butterflies, lizards, summer birds, winter birds, and rodents across 48 plots in the grasslands and mesquite-oak savannas of southeastern Arizona. Species richness and evenness were uncorrelated or weakly negatively correlated for each taxonomic group, supporting the conclusion that richness alone is an incomplete measure of diversity. In each case, richness was positively correlated with one or more measures of abundance. By contrast, evenness usually was negatively correlated with the abundance variables, reflecting the fact that plots with high evenness generally were those where all species present were about equally uncommon. Therefore richness, but not evenness, usually was a positive predictor of places of conservation value, if these are defined as places where species of interest are especially abundant. Species diversity was more positively correlated with evenness than with richness among grasshoppers and flowering plants, in contrast to the other taxonomic groups, and the positive correlations between richness and abundance were comparatively weak for grasshoppers and plants as well. Both of these differences can be attributed to the fact that assemblages of plants and grasshoppers were numerically dominated by small subsets of common species (grasses and certain spur-throated grasshoppers) whose abundances differed greatly among plots in ways unrelated to species richness of the groups as a whole.     

Method to assess component contribution to toxicity of complex mixtures: Assessment of puberty acquisition in rats exposed to disinfection byproducts

A method based on regression modeling was developed to discern the contribution of component chemicals to the toxicity of highly complex, environmentally realistic mixtures of disinfection byproducts(DBPs). Chemical disinfection of drinking water forms DBP mixtures.Because of concerns about possible reproductive and developmental toxicity, a whole mixture(WM) of DBPs produced by chlorination of a water concentrate was administered as drinking water to Sprague–Dawley(S–D) rats in a multigenerational study. Age of puberty acquisition,i.e., preputial separation(PPS) and vaginal opening(VO), was examined in male and female offspring, respectively. When compared to controls, a slight, but statistically significant delay in puberty acquisition was observed in females but not in males. WM-induced differences in the age at puberty acquisition were compared to those reported in S–D rats administered either a defined mixture(DM) of nine regulated DBPs or individual DBPs. Regression models were developed using individual animal data on age at PPS or VO from the DM study. Puberty acquisition data reported in the WM and individual DBP studies were then compared with the DM models. The delay in puberty acquisition observed in the WM-treated female rats could not be distinguished from delays predicted by the DM regression model, suggesting that the nine regulated DBPs in the DM might account for much of the delay observed in the WM. This method is applicable to mixtures of other types of chemicals and other endpoints.     

Annual migrations,diving behavior,and thermal biology of Atlantic bluefin tuna, <Emphasis Type="Italic">Thunnus thynnus</Emphasis>, on their Gulf of Mexico breeding grounds

Electronic tags were used to examine the biology of Atlantic bluefin tuna (Thunnus thynnus L.) on their breeding grounds in the Gulf of Mexico (GOM). The hypothesis that movement patterns, diving behavior, and thermal biology change during different stages of the breeding migration was tested. Mature Atlantic bluefin tuna tagged in the western Atlantic and the GOM, were on their breeding grounds from February to June for an average of 39 ± 11 days. The bluefin tuna experienced significantly warmer mean sea surface temperatures (SSTs) within the GOM (26.4 ± 1.6°C) than outside the GOM (20.2 ± 1.9°C). As the bluefin tuna entered and exited the GOM, the fish dove to daily maximum depths of 568 ± 50 and 580 ± 144 m, respectively, and exhibited directed movement paths to and from the localized breeding areas. During the putative breeding phase, the bluefin tuna had significantly shallower daily maximum depths (203 ± 76 m), and exhibited shallow oscillatory dives during the night. The movement paths of the bluefin tuna during the breeding phase were significantly more residential and sinuous. The heat transfer coefficients (K) were calculated for a bluefin tuna in the GOM using the recorded ambient and body temperatures. The K for this fish increased rapidly at the high ambient temperatures encountered in the GOM, and was significantly higher at night in the breeding phase when the fish was exhibiting shallow oscillatory dives. This suggests that the fish were behaviorally and physiologically thermoregulating in the Gulf of Mexico. This study demonstrates that the movement patterns, diving behavior, and thermal biology of Atlantic bluefin tuna change significantly at different stages of the breeding migration and can be used to define spawning location and timing. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.