Recent TIMS dating results from British Late Pleistocene vertebrate faunal localities: context and interpretation

New TIMS dates from British sites underpin and extend the growing model of mammalian faunal history during the Late Pleistocene. The sequence of British faunas during the three successive warm phases of MIS 5 presents a challenging model in which the mammal faunas of the first two temperate phases, 5e and 5c is dominated by species of a classically interglacial character, while that of the final phase, sub‐stage 5a, is dominated by bison and reindeer. This we see as the ‘cold fauna’ appearing in Britain during the cool isotope sub‐stage 5b and subsequently isolated by the rising sea level of isotope sub‐stage 5a. All these three faunas are true island faunas. Copyright © 2007 John Wiley & Sons, Ltd.     

The freshwater dissolved organic matter fluorescence–total organic carbon relationship

The fluorescent properties of dissolved organic matter (DOM) enable comparisons of humic‐like (H‐L) and fulvic‐like (F‐L) fluorescence intensities with dissolved organic carbon (DOC) in aquatic systems. The fluorescence‐DOC relationship differed in gradient, i.e. the fluorescence per gram of carbon, and in the strength of the correlation coefficient. We compare the fluorescence intensity of the F‐L and H‐L fractions and DOC of freshwater DOM in north Shropshire, England, featuring a river, wetland, spring, pond and sewage DOM sources. Correlations between fluorescence and DOC varied between sample sites. Wetland water samples for the F‐L peak gave the best correlation, r = 0·756; the lowest correlation was from final treated sewage effluent, r = 0·167. The relationship between fluorescence and DOC of commercially available International Humic Substances Society standards were also examined and they generally showed a lower fluorescence per gram of carbon for the F‐L peak than the natural samples, whereas peat wetland DOM gave a greater fluorescence per gram of carbon than river DOM. Here, we propose the strength of the fluorescence–DOC correlation to be a useful tool when discriminating sources of DOM in fresh water. Copyright © 2007 John Wiley & Sons, Ltd.     

High-resolution radio observations of Seyfert galaxies in the extended 12-μm sample – II. The properties of compact radio components

We discuss the properties of compact nuclear radio components in Seyfert galaxies from the extended 12-μm AGN sample of Rush et al. Our main results can be summarized as follows.
Type 1 and type 2 Seyferts produce compact radio components which are indistinguishable in strength and aspect, indicating that their central engines are alike, as proposed by the unification model. Infrared IRAS fluxes are more closely correlated with low-resolution radio fluxes than high-resolution radio fluxes, suggesting that they are dominated by kiloparsec-scale, extranuclear emission regions; extranuclear emission may be stronger in type 2 Seyferts. Early-type Seyfert galaxies tend to have stronger nuclear radio emission than late-type Seyfert galaxies. V-shaped extended emission-line regions, indicative of 'ionization cones', are usually found in sources with large, collimated radio outflows. Hidden broad lines are most likely to be found in sources with powerful nuclear radio sources. Type 1 and type 2 Seyferts selected by their IRAS 12-μm flux densities have well-matched properties.     

Variability in luminescent lamination and initial 230Th/232Th activity ratios in a late Holocene stalagmite from northern Norway

Luminescent lamination in a stalagmite from northern Norway is used to construct a ～2780-year long, floating record of annual growth rate. Thermal ionisation mass-spectrometric (TIMS) U–Th ages (n = 12) were determined along the growth axis and three subsample locations and ages (corrected and uncorrected for initial ²³⁰Th/²³²Th activity) were selected as anchor points for the floating chronology. On the basis of these anchor points, termination of growth occurred between AD 1729 and AD 1826. The annual banding records are used to evaluate the initial ²³⁰Th/²³²Th activity ratio adopted for correction of the U–Th ages. To achieve a reasonable fit between U–Th ages and estimates predicted by the anchored annual band age models, mean initial ²³⁰Th/²³²Th activity ratios of between 0.44 and 1.47 must be invoked. However, there remains a reasonable degree of scatter about the expected linear relationship between annual bands and U–Th chronology for individual subsamples indicating that the use of a single correction factor for Holocene stalagmites should be applied with caution.Stalagmite growth rate fluctuates on annual to centennial scale. The growth termination of the stalagmite presented here could have been a result of environmental change associated with the Little Ice Age, or, possibly local percolation pathway changes after an M_s ～ 6 earthquake in the region in AD 1819. Stable-isotope data from the same axis of growth show a pattern similar to the large-scale growth rate variations, and these combined proxy records are interpreted as showing gradual cooling and/or shortening of the vegetation growth season for the last 3000 years.     

Assessing the impact of climate change on visitor behaviour and habitat use at the coast: A UK case study

Although tourism and recreation can bring economic benefits to an area, the presence of visitors may adversely impact biodiversity, particularly if they make use of sensitive environments. It is anticipated that the effects of global climate change alone may increase the vulnerability of many environments, but these effects may be magnified if warmer and drier weather encourages more visitors, or makes them more likely to participate in ecologically damaging activities. Using case study sites from the UK, this study examines how different types of beach visitors make use of coastal environments. Via a series of visitor surveys, information is elicited on the environmental preferences of a range of visitor types including walkers, bird watchers, and bathers. The use of different habitats by these visitors is also assessed via an analysis of walking routes undertaken in a Geographical Information System. From this, an assessment is made of the likely present day biodiversity impacts arising from different coastal users, and how these may change under a modified climate. This study finds that whilst higher temperatures are expected to increase visitor numbers, warmer weather may encourage greater participation in low impact activities such as bathing. The findings are discussed in the context of coastal management.     

The Effect of Surface Heating on Hill-Induced Flow Separation

A series of two-dimensional mixing length model simulations of boundary-layer flow over idealised ridges of varying steepness are conducted to investigate the effect of surface heating on flow separation. The relatively simple numerical approach used permits characterisation of the influence of heating for a variety of initial conditions and parameter values. For steep terrain, increased surface heating is shown to enhance the strength and extent of hill-induced separation. For more moderate terrain, a critical heating strength is required for a given hill width and background flow speed before separation is initiated. Sensitivity tests show the results to be insensitive to model parameters or the choice of mixing length. The results are accounted for using a scaling analysis in terms of a non-dimensional stability parameter.     

Developing adaptive capacity for responding to environmental change in the Arab Gulf States: Uncertainties to linking ecosystem conservation, sustainable development and society in authoritarian rentier economies

The recent assessment by the Intergovernmental Panel on Climate Change (IPCC) has emphasized that understanding the institutional context in which policies are made and implemented is critical to define sustainable development paths from a climate change perspective. Nevertheless, while the importance of social, political and cultural factors is getting more recognition in some parts of the world, little is known about the human dimensions or the contexts in which they operate in the affluent oil economies of the Arabian Peninsula. Policies that implicitly subsidize or support a wasteful and environmentally destructive use of resources are still pervasive, while noteworthy environmental improvements still face formidable political and institutional constraints to the adaptation of the necessary far reaching and multisectoral approach. The principal aim of this paper is to identify some of the major shortcomings within the special context of the Arab Gulf states' socio-cultural environment in support of appropriate development pathways. Conclusions highlight that past and current policy recommendations for mitigating environmental threats are likely to be ineffective. This is because they are based on the unverified assumption that Western-derived standards of conduct, specifically the normative concept of ”good governance” and ”democracy”, will be adopted in non-Western politico-cultural contexts.     

The Carbonate Chemistry of the “Fattening Line,” Willapa Bay, 2011–2014

Willapa Bay has received a great deal of attention in the context of rising atmospheric CO₂ and the concomitant effects of changes in bay carbonate chemistry, referred to as ocean acidification, and the potential effects on the bay’s naturalized Pacific oyster (Crassostrea gigas) population and iconic oyster farming industry. Competing environmental stressors, historical variability in the oyster settlement record, and the absence of adequate historical observations of bay-water carbonate chemistry all conspire to cast confusion regarding ocean acidification as the culprit for recent failures in oyster larval settlement. We present the first measurements of the aqueous CO₂ partial pressure (PCO₂) and the total dissolved carbonic acid (TCO₂) at the “fattening line,” a location in the bay that has been previously identified as optimal for both larval oyster retention and growth, and collocated with a long historical time series of larval settlement. Samples were collected from early 2011 through late 2014. These measurements allow the first rigorous characterization of Willapa Bay aragonite mineral saturation state (Ω_ar), which has been shown to be of leading importance in determining the initial shell formation and growth of larval Crassostrea gigas. Observations show that the bay is usually below Ω_ar levels that have been associated with poor oyster hatchery production and with chronic effects noted in experimental work. Bay water only briefly rises to favorable Ω_ar levels and does so out of phase with optimal thermal conditions for spawning. Thermal and carbonate conditions are thus coincidentally favorable for early larval development for only a few weeks at a time each year. The limited concurrent exceedance of thermal and Ω_ar thresholds suggests the likelihood of high variability in settlement success, as seen in the historical record; however, estimates of the impact of elevated atmospheric CO₂ suggest that pre-industrial Ω_ar conditions were more persistently favorable for larval development and more broadly coincident with thermal optima.     

A way forward on adaptation to climate change in Colombian agriculture: perspectives towards 2050

Policy measures regarding adaptation to climate change include efforts to adjust socio-economic and ecologic systems. Colombia has undertaken various measures in terms of climate change mitigation and adaptation since becoming a party of the Kyoto protocol in 2001 and a party of the United Nations Framework Convention on Climate Change (UNFCCC) in 1995. The first national communication to the UNFCCC stated how Colombian agriculture will be severely impacted under different emission scenarios and time frames. The analyses in this document further support that climate change will severely threaten the socioeconomics of Colombian agriculture. We first query national data sources to characterize the agricultural sector. We then use 17 Global Circulation Model (GCM) outputs to quantify how Colombian agricultural production may be affected by climate change, and show the expected changes to years 2040–2069 (“2050”) under the A2 scenario of the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (SRES-A2) and the overall trends in both precipitation and temperature to 2100. We then evaluate expected changes within different regions and measure the proportion of area affected within each crop’s distributional range. By 2050, climatic change in Colombia will likely impact 3.5 million people, 14?% of national GDP corresponding to agriculture, employment of 21?% of the population, agro-industries, supply chains, and food and nutritional security. If no adaptation measures are taken, 80?% of crops would be impacted in more than 60?% of their current areas of cultivation, with particularly severe impacts in high value perennial and exportable crops. Impacts also include soil degradation and organic matter losses in the Andes hillsides; likely flooding in the Caribbean and Pacific coasts; niche losses for coffee, fruit, cocoa, and bananas; changes in prevalence of pests and diseases; and increases in the vulnerabilities of non-technically developed smallholders. There is, however, still time to change the current levels of vulnerability if a multidisciplinary focus (i.e., agronomic, economic, and social) in vulnerable sectors is undertaken. Each sub-sector and the Government need to invest in: (1) data collection, (2) detailed, regionally-based impact assessments, (3) research and development, and (4) extension and technology transfer. Support to vulnerable smallholders should be given by the state in the form of agricultural insurance systems contextualized under the phenomenon of climate change. A national coordination scheme led by (but not restricted to) the Ministry of Agriculture and Rural Development (MADR) with the contributions of national and international institutions is needed to address agricultural adaptation.