Reply to "Mega-highstand or megatsunami? Discussion of McMurtry et al. "Elevated marine deposits in Bermuda record a late Quaternary megatsunami": Sed. Geol. 200 (2007) 155-165" by Paul J. Hearty and Storrs L. Olson

Our recent paper [McMurtry, G.M., Tappin, D.R., Sedwick, P.N., Wilkinson, I., Fietzkc, J. and Sellwood, B., 2007a. Elevated marine deposits in Bermuda record a late Quaternary megatsunami. Sedimentary Geol. 200, 155-165.] critically re-examined elevated marine deposits in Bermuda, and concluded that their geological setting, sedimentary relations, micropetrography and microfaunal assemblages were inconsistent with sustained intertidal deposition. Instead, we hypothesized that these deposits were the result of a large tsunami that impacted the Bermuda island platform during the mid-Pleistocene. Hearty and Olson [Hearty, P.J., and Olson, S.L., in press. Mega-highstand or megatsunami? Discussion of McMurtry et al. "Elevated marine deposits in Bermuda record a late Quaternary megatsunami": Sedimentary Geology, 200, 155-165, 2007 (Aug. 07). Sedimentary Geol. 200, 155-165.] in their response, attempt to refute our conclusions and claim the deposits to be the result of a +21 m eustatic sea level highstand during marine isotope stage (MIS) 11. In our reply we answer the issues raised by Hearty and Olson [Hearty, P.J., and Olson, S.L., in press. Mega-highstand or megatsunami? Discussion of McMurtry et al. "Elevated marine deposits in Bermuda record a late Quaternary megatsunami": Sedimentary Geology, 200, 155-165, 2007 (Aug. 07). Sedimentary Geol. 200,155-165.] and conclude that the Bermuda deposits do not provide unequivocal evidence of a prolonged +21 m eustatic sea level highstand. Rather, the sediments are more likely the result of a past megatsunami in the North Atlantic basin. (c) 2008 Elsevier B.V. All rights reserved.

Neolithic woodland composition and exploitation in the Southern Levant: a comparison between archaeobotanical remains from WF16 and present day woodland at Hammam Adethni

Excavations at the Pre-Pottery Neolithic site of WF16 in the Southern Levant produced an archaeobotanical assemblage constituted by plant macro-fossils and wood charcoal. As with all such assemblages, its species composition will most likely provide a biased reflection of those within the Neolithic woodland that had been exploited owing to cultural selection and differential preservation. As a means of facilitating its interpretation, a survey was undertaken of a relatively undisturbed patch of gallery woodland associated with a permanent water course at Hammam Adethni, approximately four kilometres south-east of WF16. The substantial overlap of the species within this woodland and those in the archaeobotanical assemblage suggests that this present-day woodland provides an analogue for that of the Neolithic and may therefore indicate what other plant resources the inhabitants of WF16 may have exploited, but which have left no archaeological trace. The interpretation of the results is supported by a comparative study of wood charcoal from present-day Bedouin hearths in Wadi Faynan.

Does changing the taxonomical resolution alter the value of soil macroinvertebrates as bioindicators of metal pollution?

Ecological indicators are taxa that are affected by, and indicate effects of, anthropogenic environmental stress or disturbance on ecosystems. There is evidence that some species of soil macrofauna (i.e. diameter > 2 min) constitute valuable biological indicators of certain types of soil perturbations. This study aims to determine which level of taxonomic resolution, (species, family or ecological group) is the best to identify indicator of soil disturbance. Macrofauna were sampled in a set of sites encompassing different land-use systems (e.g. forests, pastures, crops) and different levels of pollution. Indicator taxa were sought using the IndVal index proposed by Dufrene and Legendre [Dufrene, M., Legendre, P., 1997. Species assemblages and indicator species: the need for a flexible asymetrical approach. Ecological Monographs 67, 345-3661. This approach is based on a hierarchical typology of sites. The index value changes along the typology and decreases (increases) for generalist (specialist) faunal units (species, families or ecological groups). Of the 327 morphospecies recorded, 19 were significantly associated with a site type or a group of sites (5.8%). Similarly, species were aggregated to form 59 families among which 17 (28.8%) displayed a significant indicator value. Gathering species into 28 broad ecological assemblages led to 14 indicator groups (50%). Beyond the simple proportion of units having significant association with a given level of the site typology, the proportion of specialist and generalist groups changed dramatically when the level of taxonomic resolution was altered. At the species level 84% of the indicator units were specialist, whereas this proportion decreased to 70 and 43% when families and ecological groups were considered. Because specialist groups are the most interesting type of indicators either in terms of conservation or for management purposes we come to the conclusion that the species level is the most accurate taxonomic level in bioindication studies although it requires a high amount of labour and operator knowledge and is time-consuming. (c) 2005 Published by Elsevier Ltd.

Inorganic synthesis of Fe-Ca-Mg carbonates at low temperature

A set of free-drift experiments was undertaken to synthesize carbonates of mixed cation content (Fe, Ca, Mg) from solution at 25 and 70 degrees C to better understand the relationship between the mineralogy and composition of these phases and the solutions from which they precipitate. Metastable solid solutions formed at 25 degrees C which are not predicted from the extrapolation of higher temperature equilibrium assemblages; instead, solids formed that were intermediary in chemical composition to known magnesite-siderite and dolomite solid solutions. A calcite-siderite solid solution precipitated at 25 degrees C, with the percentage of CaCO3 in the solid being proportional to the aqueous Ca/Fe ratio of the solution, while Mg was excluded from the crystal structure except at relatively high aqueous Mg/Ca and Mg/Fe ratios and a low Ca content. Alternatively, at 70 degrees C Mg was the predominant cation of the solid solutions. These results are compatible with the hypothesis that the relative dehydration energies of Fe, Ca and Mg play an important role in the formation of mixed cation carbonates in nature. (C) 2009 Elsevier Ltd. All rights reserved.

Effects of patch size and density on flower visitation and seed set of wild plants: a pan-European approach

1. Habitat fragmentation can affect pollinator and plant population structure in terms of species composition, abundance, area covered and density of flowering plants. This, in turn, may affect pollinator visitation frequency, pollen deposition, seed set and plant fitness. 2. A reduction in the quantity of flower visits can be coupled with a reduction in the quality of pollination service and hence the plants’ overall reproductive success and long-term survival. Understanding the relationship between plant population size and⁄ or isolation and pollination limitation is of fundamental importance for plant conservation. 3. Weexamined flower visitation and seed set of 10 different plant species fromfive European countries to investigate the general effects of plant populations size and density, both within (patch level) and between populations (population level), on seed set and pollination limitation. 4. Wefound evidence that the effects of area and density of flowering plant assemblages were generally more pronounced at the patch level than at the population level. We also found that patch and population level together influenced flower visitation and seed set, and the latter increased with increasing patch area and density, but this effect was only apparent in small populations. 5. Synthesis. By using an extensive pan-European data set on flower visitation and seed set we have identified a general pattern in the interplay between the attractiveness of flowering plant patches for pollinators and density dependence of flower visitation, and also a strong plant species-specific response to habitat fragmentation effects. This can guide efforts to conserve plant–pollinator interactions, ecosystem functioning and plant fitness in fragmented habitats.

Parallel declines in pollinators and insect-pollinated plants in Britain and the Netherlands

Despite widespread concern about declines in pollination services, little is known about the patterns of change in most pollinator assemblages. By studying bee and hoverfly assemblages in Britain and the Netherlands, we found evidence of declines (pre- versus post-1980) in local bee diversity in both countries; however, divergent trends were observed in hoverflies. Depending on the assemblage and location, pollinator declines were most frequent in habitat and flower specialists, in univoltine species, and/or in nonmigrants. In conjunction with this evidence, outcrossing plant species that are reliant on the declining pollinators have themselves declined relative to other plant species. Taken together, these findings strongly suggest a causal connection between local extinctions of functionally linked plant and pollinator species.

Arthropod community structure in pastures of an island archipelago (Azores): looking for local-regional species richness patterns at fine-scales

The arthropod species richness of pastures in three Azorean islands was used to examine the relationship between local and regional species richness over two years. Two groups of arthropods, spiders and sucking insects, representing two functionally different but common groups of pasture invertebrates were investigated. The local-regional species richness relationship was assessed over relatively fine scales: quadrats (= local scale) and within pastures (= regional scale). Mean plot species richness was used as a measure of local species richness (= alpha diversity) and regional species richness was estimated at the pasture level (= gamma diversity) with the 'first-order-Jackknife' estimator. Three related issues were addressed: (i) the role of estimated regional species richness and variables operating at the local scale (vegetation structure and diversity) in determining local species richness; (ii) quantification of the relative contributions of alpha and beta diversity to regional diversity using additive partitioning; and (iii) the occurrence of consistent patterns in different years by analysing independently between-year data. Species assemblages of spiders were saturated at the local scale (similar local species richness and increasing beta-diversity in richer regions) and were more dependent on vegetational structure than regional species richness. Sucking insect herbivores, by contrast, exhibited a linear relationship between local and regional species richness, consistent with the proportional sampling model. The patterns were consistent between years. These results imply that for spiders local processes are important, with assemblages in a particular patch being constrained by habitat structure. In contrast, for sucking insects, local processes may be insignificant in structuring communities.

Grassland leafhoppers (Hemiptera: Auchenorrhyncha) as indicators of habitat condition - a comparison of between-site and between-year differences in assemblage composition

The Auchenorrhyncha (leafhoppers) show great potential as indicators of grassland habitat quality, which would make them useful as a conservation tool. However, they are known to have labile populations. The relative importance of site identity and the year of sampling in the composition of leafhopper assemblages on chalk grassland are assessed for two sets of sites sampled twice. The study included a total of 95 sites (one set of 54, the other of 41), and demonstrated that for both sets the vegetation community and geographical location had high explanatory value, while the influence of year was small. The conclusion is that, notwithstanding population fluctuations, the leafhopper assemblages are a good indicator of habitat quality, and represent a potentially valuable tool in grassland conservation and restoration.

Community associations of chalk grassland leafhoppers (Auchenorrhyncha): conclusions for habitat conservation

Due to their confinement to specific hostplants or restricted habitat types, Auchenorrhyncha have the potential to make suitable biological indicators to measure the quality of chalk grassland under different management practices for nature conservation. The Auchenorrhyncha data from a study designed to identify the factors influencing the invertebrate diversity of chalk grasslands in southern England was used to evaluate the potential use of this group of insects as biological indicators. Between 1998 and 2002 altogether 81 chalk grassland sites were sampled. Vegetation structure and composition were recorded, and Auchenorrhyncha were sampled at each site on three occasions in each of two seasons using a ‘Vortis’ suction sampler. Auchenorrhyncha assemblages were then linked to the different grassland plant communities occurring on chalk soils according to the British National Vegetation Classification (NVC). Altogether 96 Auchenorrhyncha species were recorded during the study. Using data on the frequency and dominance of species, as is commonly done for plant communities, it was possible to identify the preferential and differential species of distinct Auchenorrhyncha assemblages. Significant differences between the Auchenorrhyncha assemblages associated with the various chalk grassland plant communities of the NVC were observed down to a level of sub-communities. We conclude that data on Auchenorrhyncha assemblages can provide valuable information for the setting of conservation management priorities, where data on floristic composition alone may not be sufficient, providing additional information on aspects of vegetation structure and condition.

Enhancing pollinator biodiversity in intensive grasslands

Increased agricultural intensification has led to well-documented declines in the fauna and flora associated with intensive grasslands in the UK. We aimed to quantify the effectiveness of different field margin management strategies for putting bumblebee and butterfly biodiversity back into intensive grasslands. Using four intensive livestock farms in south-west England, we manipulated conventional management practices (addition of inorganic fertilizer, cutting frequency and height, and aftermath grazing) to generate seven grass-based treatments along a gradient of decreasing management intensity. We also tested two more interventionist treatments which introduced sown components into the sward: (i) a cereal, grass and legume mix, and (ii) a diverse conservation mix with kale, mixed cereals, linseed and legumes. These crop mixtures were intended to provide forage and structural resources for pollinators but were not intended to have agronomic value as livestock feed. Using a replicated block design, we monitored bumblebee and butterfly responses in 27 plots (10 x 50 m) in each farm from 2003 to 2006. Bumblebees were most abundant, species-rich and diverse in the sown treatments and virtually absent from the grass-based treatments. The diverse conservation mix treatment supported larger and more diverse bumblebee assemblages than the cereal, grass and legume mix treatment. The sown treatments, and the most extensively managed grass-based treatments, had the highest abundance, species richness and diversity of adult butterflies, whereas butterfly larvae were only found in the grass-based treatments. Bumblebee and butterfly assemblage structure was driven by floral abundance, floral richness, the availability of nectar resources, and sward structure. Only vegetation cover was correlated with butterfly larval abundance. Synthesis and applications. This study has identified management options in the margins of intensive grasslands which can enhance bumblebee and butterfly biodiversity. Extensification of conventional grass management by stopping fertilization, reducing cutting frequency and not grazing, benefits butterflies. However, to enhance bumblebees requires a more interventionist approach in the form of sowing flower-rich habitat. Both approaches are potentially suitable for adoption in agri-environment schemes in the UK and Europe.

Effects of summer rainfall manipulations on the abundance and vertical distribution of herbivorous soil macro-invertebrates

Soil invertebrate communities are likely to be highly vulnerable to low soil moisture, caused by a reduction in summer rainfall which is predicted for some regions under current climate change scenarios. However, the effects of changes in summer rainfall on soil invertebrate assemblages have rarely been tested experimentally. In this study, samples were taken in 2003 and 2004 from a long-running field experiment, to investigate the impact of 10 years of experimental summer drought and increased summer rainfall manipulations on the soil fauna of a calcareous grassland. Summer drought altered the soil invertebrate assemblage in the autumn, immediately following treatment application, but by the following spring treatment effects were no longer apparent. The two most common root herbivore species responded differently to the summer rainfall manipulations. Larvae of the dominant root-chewing species, Agriotes lineatus, were more numerous under enhanced rainfall in both the spring and autumn. In contrast, abundance of the Coccoidea Lecanopsis formicarum was unaffected by the rainfall manipulations. The responses of root herbivores to an increased incidence of summer droughts are therefore likely to vary, depending on their feeding strategy and life history. (c) 2007 Elsevier Masson SAS. All rights reserved.

Functional benefits of predator species diversity depend on prey identity

1. Determining the functional significance of species diversity in natural enemy assemblages is a key step towards prediction of the likely impact of biodiversity loss on natural pest control processes. While the biological control literature contains examples in which increased natural enemy diversity hinders pest control, other studies have highlighted mechanisms where pest suppression is promoted by increased enemy diversity. 2. This study aimed to test whether increased predator species diversity results in higher rates of predation on two key, but contrasting, insect pest species commonly found in the rice ecosystems of south-east Asia. 3. Glasshouse experiments were undertaken in which four life stages of a planthopper (Nilaparvata lugens) and a moth (Marasmia patnalis) were caged with single or three-species combinations of generalist predators. 4. Generally, predation rates of the three-species assemblages exceeded expectation when attacking M. patnalis, but not when attacking N. lugens. In addition, a positive effect of increased predator species richness on overall predation rate was found with M. patnalis but not with N. lugens. 5. The results are consistent with theoretical predictions that morphological and behavioural differentiation among prey life stages promotes functional complementarity among predator species. This indicates that emergent species diversity effects in natural enemy assemblages are context dependent; they depend not only on the characteristics of the predators species, but on the identity of the species on which they prey.

The potential of grass field margin management for enhancing beetle diversity in intensive livestock farms

1. Declining populations of UK grassland flora and fauna have been attributed to intensification of agricultural management practices, including changes in cutting, fertilizer, grazing and drainage regimes. We aimed to develop field margin management practices that could reverse declines in intensively managed grassland biodiversity that would have application in the UK and Europe. Here we focus on one aspect of grassland biodiversity, the beetles. 2. In four intensively managed livestock farms in south-west England, 10-m wide field margins in existing grasslands were managed to create seven treatments of increasing sward architectural complexity. This was achieved through combinations of inorganic (NPK) fertilizer, cattle grazing, and timing and height of cutting. To examine the potential influence of complexity on faunal diversity, beetles were identified to species level from suction samples taken between 2003 and 2005, and their assemblage structure was related to margin management, floral assemblages and sward architecture. 3. Beetle abundance, and species richness and evenness were influenced by margin management treatment and its interaction with year. Correlations with sward architecture and the percentage cover of dominant forbs and grasses were also found. Functional groups of the beetles showed different responses to the management treatments. In particular, higher proportional abundances of seed/flower-feeding guilds were found in treatments not receiving NPK fertilizer. 4. The assemblage structure was shown to respond to margin management treatments, sward architecture and the percentage cover of dominant forbs and grasses. The most extensively managed treatments were characterized by distinct successional trajectories from the control treatment. 5. Synthesis and applications. This study provides management options suitable for use within agri-environment schemes intended to improve faunal diversity associated with intensively managed lowland grasslands. Field margins receiving either no management or a single July silage cut were shown to support greater abundances and species richness of beetles, although subtler modifications of conventional management may also be beneficial, for example the absence of NPK fertilizer while maintaining grazing and silage cutting systems.

Can a consecutive double turn conformation be considered as a peptide based molecular scaffold for supramolecular helix in the solid state?

Helices and sheets are ubiquitous in nature. However, there are also some examples of self-assembling molecules forming supramolecular helices and sheets in unnatural systems. Unlike supramolecular sheets there are a very few examples of peptide sub-units that can be used to construct supramolecular helical architectures using the backbone hydrogen bonding functionalities of peptides. In this report we describe the design and synthesis of two single turn/bend forming peptides (Boc-Phe-Aib-Ile-OMe 1 and Boc-Ala-Leu-Aib-OMe 2) (Aib: alpha-aminoisobutyric acid) and a series of double-turn forming peptides (Boc-Phe-Aib-IIe-Aib-OMe 3, Boc-Leu-Aib-Gly-Aib-OMe 4 and Boc-gamma-Abu-Aib-Leu-Aib-OMe 5) (gamma-Abu: gamma-aminobutyric acid). It has been found that, in crystals, on self-assembly, single turn/bend forming peptides form either a supramolecular sheet (peptide 1) or a supramolecular helix (peptide 2). unlike self-associating double turn forming peptides, which have only the option of forming supramolecular helical assemblages. (c) 2005 Elsevier Ltd. All rights reserved.

The unsung heroes

This paper explores the roles played by local collectors, often little-known or rarely remembered, in the compilation of Britain’s Earlier (Lower and early Middle) Palaeolithic record, with reference to the work of C.E. (Charles) Bean at the Lower Palaeolithic site of Broom, and the activities of George Smith and Llewellyn and Mabel Treacher in the Middle Thames Valley. Their collecting practices, publication records, and archaeological knowledge and insights are reviewed, and their impacts assessed with reference to the activities of other contemporary collectors, and the regional archaeological records of the south-west and the Middle Thames. Their archives demonstrate that while the key sites and artefact assemblages sampled by Bean, Smith and the Treachers would not otherwise have been unknown, their work left important legacies in terms of rich artefact assemblages, site archives (Bean), and the long-term monitoring of key sites and fluvial terraces.