New lessons for technology policy and climate change: investment for innovation

The direction of UK energy policy requires a renewed impetus if the goal of climate change stabilization is to be met. Cost is not the main issue: a transformation to a low-carbon energy system may be no more expensive than meeting future energy demands with fossil fuels. Institutional barriers are preventing the large-scale adoption of the necessary technologies. New institutions to promote low-carbon technologies have not yet led to investment on the necessary scale. Further changes to the operation of the UK electricity markets to create a ‘level playing field’ for small-scale and intermittent generation are necessary. UK policy can contribute to international agreements following on from the Kyoto Accord, which also need to address the institutional barriers to energy technology development and transfer.     

SUSPENDED SEDIMENT DYNAMICS IN THE MORTERATSCH PRO‐GLACIAL ZONE,BERNINA ALPS,SWITZERLAND

Suspended sediment concentration (SSC) in the Ova da Morteratsch, Switzerland, measured during July 2007 was closely associated with discharge (Q) and showed statistically significant relationships at the p < 0.001 level at the proximal and distal ends of the 600 m pro‐glacial zone. SSC predicted from 10‐minute turbidity records gives a much more detailed insight into SSC fluctuations and identified SSC peaks which do not coincide with discharge peaks. Net (proximal – distal) 10‐minute suspended sediment loads (SSL) are predominantly positive (i.e. suspended sediment is being stored in the reach) for most of the 7–19 July 2007 record. Net (proximal – distal) SSLs correlate closely with discharge for the first part of the record (7–13 July) but from 14 to 19 July suspended sediment exhaustion is in evidence and discrete phases of negative net SSL (i.e. sediment flushing) are likely for up to six hours on three separate days which coincide with phases of high discharge and exhaustion of the glacial suspended sediment sources. Analysis of Q at the Berninabach–Pontresina gauging station (5 km downstream) for the past five years revealed that maximum monthly discharges capable of generating sediment flushing events occur in an average of four months each year. The study emphasises the rapid change in suspended sediment transport and yields with distance from the glacier snout and highlights the importance of measurements as close to the glacier snout as possible if data are to be representative of the glaciated land up‐valley. A better understanding of the processes of sediment exchange and the colonisation and stabilisation of sediment stores by vegetation in such pro‐glacial zones is essential if we are to improve predictions of the impacts of climate change on river sediment dynamics and the subsequent effects on aquatic ecology.     

Sediment trend models fail to reproduce small-scale sediment transport patterns on an intertidal beach

A rigorous test is presented of the application of sediment trend models to an intertidal beach environment characterized by bar morphology. Sediment samples were collected during low tide from a regular grid and their sediment fall velocity distributions, obtained using a settling tube, were analysed using moment analysis. The net sediment transport direction determined from beach surveys, hydrodynamic measurements, wave ripple observations and sediment transport modelling was compared with predictions by sediment trend models based on the spatial distribution of sediment parameters. It was found that the sediment transport pathways and patterns of sedimentation predicted using sediment trend models were at odds with field observations, and varied significantly depending on whether surface or sub‐surface sediment samples were used. The sediment trend models are thought to fail because, in energetic and morphologically variable beach environments, spatial patterns in sediment characteristics are mainly attributed to the presence of different hydrodynamic regions and associated morphology, rather than sediment pathways. The use of sediment trend models cannot replace the collection of morphological, hydrodynamic and sediment transport data in the field to define relationships between flows, forms and sedimentation patterns on a dynamic intertidal beach.     

Testate amoebae as a proxy for reconstructing Holocene water table dynamics in southern Patagonian peat bogs

Testate amoebae are abundant and diverse in Sphagnum peat bogs and have been used extensively as indicators of past water table depths. Although these unicellular protists are widely dispersed with globally similar hydrological preferences, regional variations in communities demand region‐specific transfer functions. Here we present the first transfer function for southern Patagonian bogs, based on 154 surface samples obtained from transects in five bogs sampled in 2012 and 2013. Significant variance was explained by pH, electrical conductivity and, in particular, water table depth. Transfer functions for water table were constructed using weighted averaging and evaluated by cross‐validation and independent test sets. The optimal transfer function has predictive ability, but relatively high prediction errors given the wide range in sampled water tables. The use of independent test sets, as well as cross‐validation, allows a more rigorous assessment of model performance than most previous studies. For a subset of locations we compare surface and subsurface samples to demonstrate significant differences in community composition, possibly due to vertical zonation. Our results provide the first quantification of hydrological optima and tolerances for several rare species, which may include Southern Hemisphere endemics and pave the way for palaeohydrological reconstructions in southern Patagonian bogs.