Furongian (upper Cambrian) Guole Konservat-Lagerst?tte from South China

The Guole biota contains common shelly fossils and some exceptionally well-preserved soft-bodied fossils. Stratigraphically, it is located in the mudstones and siltstones of the Sandu Formation near Guole Town, Jingxi County, Guangxi, South China. It is the first Furongian (late Cambrian) Burgess Shale-type biota found in the world, thereby filling the gap between middle Cambrian and Lower Ordovician Burgess Shale-type Lagerst?tten. Preliminary studies suggest that the Guole biota includes approximately seven metazoan groups as well as algae. These will provide important new evolutionary and ecological information.     

Farming as a livelihood source for the urban poor of Nakuru, Kenya

Farming among urban dwellers in Sub-Saharan Africa is a common phenomenon. The present study, carried out in a medium-sized town in Kenya, not only confirmed this but also showed that farming by urban dwellers in the rural areas was even more important for these households’ livelihoods than farming in town. However, those who could benefit most from farming, i.e. the urban poor, appeared to be underrepresented among urban farming households and those urban poor who did farm, either in urban or in rural areas, performed worse than the farming non-poor. The importance of farming as a livelihood source is illustrated by the fact that in years with very little or no harvest due to drought, many of the poor farming households faced food shortages.     

Do international factors influence the passage of climate change legislation?

The number of climate change laws in major economies has grown from less than 40 in 1997 to almost 500 at the end of 2013. The passage of these laws is influenced by both domestic and international factors. This article reviews the main international factors, drawing on a powerful new dataset of climate legislation in 66 national jurisdictions. We find that the propensity to legislate on climate change is heavily influenced by the passage of similar laws elsewhere, suggesting a strong and so far under-appreciated role for international policy diffusion. International treaties such as the Kyoto Protocol work in two ways. The impact of the Kyoto Protocol itself is limited to countries with formal obligations under the treaty. In addition, the prestige of hosting an international climate summit is associated with a subsequent boost in legislation. Legislators seem to respond to the expectations of climate leadership that these events bestow on their host.

Policy relevance

A global solution to climate change will ultimately have to be anchored in domestic legislation, which creates the legal basis for countries to take action. Countries are passing climate legislation in a growing number. This article asks to what extent they are motivated to do so by international factors, such as existing treaty obligations. We find that the Kyoto Protocol has been a less important factor in explaining climate legislation outside Annex I than the passage of similar laws elsewhere. This suggests that international policy diffusion plays an important and so far under-appreciated role in global climate policy, complementing formal treaty obligations.     

Biogeographic variability in the physiological response of the cold‐water coral Lophelia pertusa to ocean acidification

While ocean acidification is a global issue, the severity of ecosystem effects is likely to vary considerably at regional scales. The lack of understanding of how biogeographically separated populations will respond to acidification hampers our ability to predict the future of vital ecosystems. Cold‐water corals are important drivers of biodiversity in ocean basins across the world and are considered one of the most vulnerable ecosystems to ocean acidification. We tested the short‐term physiological response of the cold‐water coral Lophelia pertusa to three pH treatments (pH = 7.9, 7.75 and 7.6) for Gulf of Mexico (USA) and Tisler Reef (Norway) populations, and found that reductions in seawater pH elicited contrasting responses. Gulf of Mexico corals exhibited reductions in net calcification, respiration and prey capture rates with decreasing pH. In contrast, Tisler Reef corals showed only slight reductions in net calcification rates under decreased pH conditions while significantly elevating respiration and capture rates. These differences are likely the result of environmental differences (depth, pH, food supply) between the two regions, invoking the potential for local adaptation or acclimatization to alter their response to global change. However, it is also possible that variations in the methodology used in the experiments contributed to the observed differences. Regardless, these results provide insights into the resilience of L. pertusa to ocean acidification as well as the potential influence of regional differences on the viability of species in future oceans.     

Progress and Challenges in Coupled Hydrodynamic-Ecological Estuarine Modeling

Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review, we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a “theory of everything” for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy.     

Surface water–groundwater exchange dynamics in a tidal freshwater zone

In coastal rivers, tides can propagate for tens to hundreds of kilometres inland beyond the saltwater line. Yet the influence of tides on river–aquifer connectivity and solute transport in tidal freshwater zones (TFZs) is largely unknown. We estimate that along the TFZ of White Clay Creek (Delaware, USA), 11% of river water exchanges through tidal bank storage zones. Additional hyporheic processes such as flow through bedforms likely contribute even more exchange. The turnover length associated with tidal bank storage is 150 km, on the order of turnover lengths for all hyporheic exchange processes in non‐tidal rivers of similar size. Based on measurements at a transect of piezometers located 17 km from the coast, tides exchange 0.36 m³ of water across the banks and 0.86 m³ across the bed per unit river length. Exchange fluxes range from ?1.66 to 2.26 m day^?1 across the bank and ?0.84 to 1.88 m day^?1 across the bed. During rising tide, river water infiltrates into the riparian aquifer, and the downstream transport rate in the channel is low. During falling tide, stored groundwater is released to the river, and the downstream transport rate in the channel increases. Tidal bank storage zones may remove nutrients or other contaminants from river water and attenuate nutrient loads to coasts. Alternating expansion and contraction of aerobic zones in the riparian aquifer likely influence contaminant removal along flow paths. A clear need exists to understand contaminant removal and other ecosystem services in TFZs and adopt best management practices to promote these ecosystem services. Copyright © 2015 John Wiley & Sons, Ltd.     

Aeolian dust in the Talos Dome ice core (East Antarctica,Pacific/Ross Sea sector): Victoria Land versus remote sources over the last two climate cycles

A new ice core (TALDICE) drilled at Talos Dome (East Antarctica, Ross Sea sector) preserves a ca. 250 ka long record of palaeoclimate and atmospheric history. We investigate dust variability and provenance at the site during glacial periods and the Holocene through the Sr–Nd isotopic composition of ice core dust and potential source areas (PSA). We provide new isotopic data on dust sources from Victoria Land such as regoliths, glacial drifts, aeolian sands and beach deposits. Some of these sources are located at high altitude and are known to have been ice free throughout the Pleistocene. The major features of the TALDICE dust record are very similar to those from central East Antarctica. During glacial times, South America was the dominant dust supplier for Talos Dome as well as for the entire East Antarctic plateau. Conversely, during the Holocene the principal input of mineral dust at Talos Dome probably derives from proximal sources which are the ice‐free areas of northern Victoria Land, located at similar altitude with respect to the drilling site. Atmospheric mobilisation of dust from these neighbouring areas and transport inland to Talos Dome can be ultimately associated with advection of maritime air masses from the Pacific/Ross Sea region. Copyright © 2010 John Wiley & Sons, Ltd.     

‘State,Science and the Skies: Governmentalities of the British atmosphere’, by Mark Whitehead (2009): a critical review

This critical review debates the issues raised in Mark Whitehead’s 2009 book, “State, Science and the Skies: Governmentalities of the British atmosphere”. After a short introduction that positions the book, four commentators draw on their own work in political geography, the sociology of science, atmospheric science and cultural geography, respectively, to offer sympathetic critiques of the book and its arguments. The critical review concludes with a response by the author to the issues raised.