Palaeoenvironmental changes during the Valanginian: new insights from variations in phosphorus contents and bulk- and clay mineralogies in the western Tethys

Paleoenvironmental and paleoclimatic changes during the Valanginian carbon isotopic excursion (CIE) have been investigated in the western Tethys. For this purpose, bulk-rock and clay mineralogies, as well as phosphorus (P) contents were evaluated in a selection of five sections located in the Vocontian Basin (Angles, SE France; Alvier, E Switzerland; Malleval, E France), and the Lombardian Basin (Capriolo, N Italy; Breggia, S Switzerland). Within the CIE interval, bulk-rock and clay mineralogies are inferred to reflect mostly climate change. The onset of the CIE (Busnardoites campylotoxus ammonite Zone) is characterized by higher detrital index (DI: sum of the detrital minerals divided by calcite contents) values and the presence of kaolinite in their clay-mineral assemblages. In the late Valanginian (from the Saynoceras verrucosum Zone up to the end of the Valanginian), the samples show relatively variable DI and lower values or the absence of kaolinite. The variation in the mineralogical composition is interpreted as reflecting a change from a climate characterized by optimal weathering conditions associated with an increase in terrigenous input on the southern European margin during the CIE towards an overall unstable climate associated with drier conditions in the late Valanginian. This is contrasted by a dissymmetry (proximal vs distal) along the studied transect, the northern Tethyan margin being more sensitive to changes in continental input compared to the distal environments. P accumulation rates (PAR) present similar features. In the Vocontian basin, P content variations are associated with changes in terrigenous influx, whereas in the Lombardian basin (i.e. Capriolo and Breggia), PAR values are less well correlated. This is mainly because the deeper part of the Tethys was less sensitive to changes in continental inputs. The onset of the CIE (top of the B. campylotoxus Zone) records a general increase in PAR suggesting an increase in marine nutrient levels. This is linked to higher continental weathering rates and the enhanced influx of nutrients into the ocean. In the period corresponding to the shift itself, P contents show a dissymmetry between the Vocontian and Lombardian basins (proximal vs distal). For the sections of Malleval, Alvier and Angles, a decrease in P concentrations associated to a decrease in detrital input is observed. In Capriolo and Breggia, PAR show maximum values during the plateau, indicating a more complex interaction between different P sources. The time interval including the top of S. verrucosum Zone up to the end of the Valanginian is characterized by variable PAR values, suggesting variable nutrient influxes. These changes are in agreement with an evolution towards seasonally contrasted conditions in the late Valanginian.

Eemian and Holocene sea-surface conditions in the southern Black Sea: organic-walled dinoflagellate cyst record from core 22-GC3/3

In order to compare the sea-surface conditions in the Black Sea during the Holocene and Eemian, sapropelic parts of marine core 22-GC3 (42°13.53′N/36°29.55′E, 838 m water depth) were studied for organic-walled dinoflagellate cyst content. The record shows a change from freshwater/brackish assemblages (Pyxidinopsis psilata, Spiniferites cruciformis, and Caspidinium rugosum) to more marine assemblages (Lingulodinium machaerophorum and Spiniferites ramosus complex) during each interglacial, due to the inflow of saline Mediterranean water. The lacustrine–marine transitions in 22-GC3 occurred at ~ 8.3 cal kyr BP during the early Holocene and ~ 128 kyr BP during the early Eemian, slightly later compared to the onset of interglacial conditions on the adjacent land. Dinoflagellate cyst assemblages reveal higher sea-surface salinity (~ 28–30) (e.g. Spiniferites pachydermus, Bitectatodinium tepikiense, and Spiniferites mirabilis) around ~ 126.5–121 kyr BP in comparison to the Holocene (~ 15–20) as well as relatively high sea-surface temperature (e.g. Tuberculodinium vancampoae, S. pachydermus, and S. mirabilis) especially at ~ 127.6–125.3 kyr BP. Establishment of high sea-surface salinity during the Eemian correlates very well with reconstructed relatively high global sea-level and is explained as a combined effect of increased Mediterranean supply and high temperatures at the beginning of the last interglacial. The observed changes in the dinocyst record highlight the importance of nutrients for the composition of the Eemian and Holocene dinocyst assemblages.

The new localism, anti-political development machines, and the role of planning consultants: lessons from London's South Bank

This paper draws on a study of the politics of development planning in London’s South Bank to examine wider trends in the governance of contemporary cities. It assesses the impacts and outcomes of so-called new localist reforms and argues that we are witnessing two principal trends. First, governance processes are increasingly dominated by anti-democratic development machines, characterized by new assemblages of public- and private-sector experts. These machines reflect and reproduce a type of development politics in which there is a greater emphasis on a pragmatic realism and a politics of delivery. Second, the presence of these machines is having a significant impact on the politics of planning. Democratic engagement is not seen as the basis for new forms of localism and community control. Instead, it is presented as a potentially disruptive force that needs to be managed by a new breed of skilled private-sector consultant. The paper examines these wider shifts in urban politics before focusing on the connections between emerging development machines and local residential and business communities. It ends by highlighting some of the wider implications of change for democratic modes of engagement and nodes of resistance in urban politics.

What is Carbon? Conceptualising carbon and capabilities in the context of community sequestration projects in the global South

Carbon has been described as a ‘surreal commodity’. Whilst carbon trading, storage, sequestration and emissions have become a part of the contemporary climate lexicon, how carbon is understood, valued and interpreted by actors responsible for implementing carbon sequestration projects is still unclear. In this review paper, we are concerned with how carbon has come to take on a range of meanings, and in particular, we appraise what is known about the situated meanings that people involved in delivering, and participating in, carbon sequestration projects in the global South assign to this complex element. Whilst there has been some reflection on the new meanings conferred on carbon via the neoliberal processes of marketisation, and how these processes interact with historical and contemporary narratives of environmental change, less is known about how these meanings are (re)produced and (re)interpreted locally. We review how carbon has been defined both as a chemical element and as a tradable, marketable commodity, and discuss the implications these global meanings might have for situated understandings, particularly linked to climate change narratives, amongst communities in the global South. We consider how the concept of carbon capabilities, alongside theoretical notions of networks, assemblages and local knowledges of the environment and nature, might be useful in beginning to understand how communities engage with abstract notions of carbon. We discuss the implications of specific values attributed to carbon, and therefore to different ecologies, for wider conceptualisations of how nature is valued, and climate is understood, and particularly how this may impact on community interactions with carbon sequestration projects. Knowing more about how people understand, value and know carbon allows policies to be better informed and practices more effectively targeted at engaging local populations meaningfully in carbon-related projects.

Freezing skeletal muscle tissue does not affect its decomposition in soil: Evidence from temporal changes in tissue mass, microbial activity and soil chemistry based on excised samples

The study of decaying organisms and death assemblages is referred to as forensic taphonomy, or more simply the study of graves. This field is dominated by the fields of entomology, anthropology and archaeology. Forensic taphonomy also includes the study of the ecology and chemistry of the burial environment. Studies in forensic taphonomy often require the use of analogues for human cadavers or their component parts. These might include animal cadavers or skeletal muscle tissue. However, sufficient supplies of cadavers or analogues may require periodic freezing of test material prior to experimental inhumation in the soil. This study was carried out to ascertain the effect of freezing on skeletal muscle tissue prior to inhumation and decomposition in a soil environment under controlled laboratory conditions. Changes in soil chemistry were also measured. In order to test the impact of freezing, skeletal muscle tissue (Sus scrofa) was frozen (−20 °C) or refrigerated (4 °C). Portions of skeletal muscle tissue (∼1.5 g) were interred in microcosms (72 mm diameter × 120 mm height) containing sieved (2 mm) soil (sand) adjusted to 50% water holding capacity. The experiment had three treatments: control with no skeletal muscle tissue, microcosms containing frozen skeletal muscle tissue and those containing refrigerated tissue. The microcosms were destructively harvested at sequential periods of 2, 4, 6, 8, 12, 16, 23, 30 and 37 days after interment of skeletal muscle tissue. These harvests were replicated 6 times for each treatment. Microbial activity (carbon dioxide respiration) was monitored throughout the experiment. At harvest the skeletal muscle tissue was removed and the detritosphere soil was sampled for chemical analysis. Freezing was found to have no significant impact on decomposition or soil chemistry compared to unfrozen samples in the current study using skeletal muscle tissue. However, the interment of skeletal muscle tissue had a significant impact on the microbial activity (carbon dioxide respiration) and chemistry of the surrounding soil including: pH, electroconductivity, ammonium, nitrate, phosphate and potassium. This is the first laboratory controlled study to measure changes in inorganic chemistry in soil associated with the decomposition of skeletal muscle tissue in combination with microbial activity.

Evaluation of the realism of climate reconstruction using the Coexistence Approach with modern pollen samples from the Tibetan Plateau

We apply the Coexistence Approach (CoA) to reconstruct mean annual precipitation (MAP), mean annual temperature (MAT), mean temperature of thewarmestmonth (MTWA) and mean temperature of the coldest month (MTCO) at 44 pollen sites on the Qinghai–Tibetan Plateau. The modern climate ranges of the taxa are obtained (1) from county-level presence/absence data and (2) from data on the optimum and range of each taxon from Lu et al. (2011). The CoA based on the optimumand range data yields better predictions of observed climate parameters at the pollen sites than that based on the county-level data. The presence of arboreal pollen, most of which is derived fromoutside the region, distorts the reconstructions. More reliable reconstructions are obtained using only the non-arboreal component of the pollen assemblages. The root mean-squared error (RMSE) of the MAP reconstructions are smaller than the RMSE of MAT, MTWA and MTCO, suggesting that precipitation gradients are the most important control of vegetation distribution on the Qinghai–Tibetan Plateau. Our results show that CoA could be used to reconstruct past climates in this region, although in areas characterized by open vegetation the most reliable estimates will be obtained by excluding possible arboreal contaminants.

EDITOR'S CHOICE: REVIEW: Trait matching of flower visitors and crops predicts fruit set better than trait diversity

Understanding the relationships between trait diversity, species diversity and ecosystem functioning is essential for sustainable management. For functions comprising two trophic levels, trait matching between interacting partners should also drive functioning. However, the predictive ability of trait diversity and matching is unclear for most functions, particularly for crop pollination, where interacting partners did not necessarily co-evolve. World-wide, we collected data on traits of flower visitors and crops, visitation rates to crop flowers per insect species and fruit set in 469 fields of 33 crop systems. Through hierarchical mixed-effects models, we tested whether flower visitor trait diversity and/or trait matching between flower visitors and crops improve the prediction of crop fruit set (functioning) beyond flower visitor species diversity and abundance. Flower visitor trait diversity was positively related to fruit set, but surprisingly did not explain more variation than flower visitor species diversity. The best prediction of fruit set was obtained by matching traits of flower visitors (body size and mouthpart length) and crops (nectar accessibility of flowers) in addition to flower visitor abundance, species richness and species evenness. Fruit set increased with species richness, and more so in assemblages with high evenness, indicating that additional species of flower visitors contribute more to crop pollination when species abundances are similar. Synthesis and applications. Despite contrasting floral traits for crops world-wide, only the abundance of a few pollinator species is commonly managed for greater yield. Our results suggest that the identification and enhancement of pollinator species with traits matching those of the focal crop, as well as the enhancement of pollinator richness and evenness, will increase crop yield beyond current practices. Furthermore, we show that field practitioners can predict and manage agroecosystems for pollination services based on knowledge of just a few traits that are known for a wide range of flower visitor species.

Evaluation of a modern-analogue methodology for reconstructing Australian palaeoclimate from pollen

Quantitative palaeoclimate reconstructions are widely used to evaluate climatemodel performance. Here, as part of an effort to provide such a data set for Australia, we examine the impact of analytical decisions and sampling assumptions on modern-analogue reconstructions using a continent-wide pollen data set. There is a high degree of correlation between temperature variables in the modern climate of Australia, but there is sufficient orthogonality in the variations of precipitation, summer and winter temperature and plant–available moisture to allow independent reconstructions of these four variables to be made. The method of analogue selection does not affect the reconstructions, although bootstrap resampling provides a more reliable technique for obtaining robust measures of uncertainty. The number of analogues used affects the quality of the reconstructions: the most robust reconstructions are obtained using 5 analogues. The quality of reconstructions based on post-1850 CE pollen samples differ little from those using samples from between 1450 and 1849 CE, showing that European post settlement modification of vegetation has no impact on the fidelity of the reconstructions although it substantially increases the availability of potential analogues. Reconstructions based on core top samples are more realistic than those using surface samples, but only using core top samples would substantially reduce the number of available analogues and therefore increases the uncertainty of the reconstructions. Spatial and/or temporal averaging of pollen assemblages prior to analysis negatively affects the subsequent reconstructions for some variables and increases the associated uncertainties. In addition, the quality of the reconstructions is affected by the degree of spatial smoothing of the original climate data, with the best reconstructions obtained using climate data froma 0.5° resolution grid, which corresponds to the typical size of the pollen catchment. This study provides a methodology that can be used to provide reliable palaeoclimate reconstructions for Australia, which will fill in a major gap in the data sets used to evaluate climate models.

Environmental controls on the distribution and diversity of lentic Chironomidae (Insecta: Diptera) across an altitudinal gradient in tropical South America

To predict the response of aquatic ecosystems to future global climate change, data on the ecology and distribution of keystone groups in freshwater ecosystems are needed. In contrast to mid- and high-latitude zones, such data are scarce across tropical South America (Neotropics). We present the distribution and diversity of chironomid species using surface sediments of 59 lakes from the Andes to the Amazon (0.1–17°S and 64–78°W) within the Neotropics. We assess the spatial variation in community assemblages and identify the key variables influencing the distributional patterns. The relationships between environmental variables (pH, conductivity, depth, and sediment organic content), climatic data, and chironomid assemblages were assessed using multivariate statistics (detrended correspondence analysis and canonical correspondence analysis). Climatic parameters (temperature and precipitation) were most significant in describing the variance in chironomid assemblages. Temperature and precipitation are both predicted to change under future climate change scenarios in the tropical Andes. Our findings suggest taxa of Orthocladiinae, which show a preference to cold high-elevation oligotrophic lakes, will likely see range contraction under future anthropogenic-induced climate change. Taxa abundant in areas of high precipitation, such as Micropsectra and Phaenopsectra, will likely become restricted to the inner tropical Andes, as the outer tropical Andes become drier. The sensitivity of chironomids to climate parameters makes them important bio-indicators of regional climate change in the Neotropics. Furthermore, the distribution of chironomid taxa presented here is a vital first step toward providing urgently needed autecological data for interpreting fossil chironomid records of past ecological and climate change from the tropical Andes.

Agricultural innovations at a Late Iron Age oppidum: archaeobotanical evidence for flax, food and fodder from Calleva Atrebatum, UK

The development of oppida in the late first millennium BC across north-western Europe represents a major change in settlement form and social organisation. The construction of extensive earthwork systems, the presence of nucleated settlement areas, long-distance trade links and the development of hierarchical societies have been evidenced. These imply that changes in the style and organisation of agriculture would have been required to support these proto-urban population centres. Hypotheses of the subsistence bases of these settlements, ranging from a reliance on surplus arable production from local rural settlements, to an emphasis on pastoral activities, are here reviewed and grounded against a wider understanding of the expansion of agriculture in the Late Iron Age. These agricultural models have not been previously evaluated. This paper presents archaeobotanical data from six well fills from large-scale excavations at Late Iron Age and Early Roman Silchester, a Late Iron Age territorial oppidum and subsequent Roman civitas capital located in central-southern Britain. This is the first large-scale study of waterlogged plant macrofossils from within a settlement area of an oppidum. Waterlogged plant macrofossils were studied from a series of wells within the settlement. An assessment of taphonomy, considering stratigraphic and contextual information, is reported, followed by an analysis of the diverse assemblages of the plant remains through univariate analysis. Key results evidence animal stabling, flax cultivation, hay meadow management and the use of heathland resources. The staple crops cultivated and consumed at Late Iron Age and Early Roman Silchester are consistent with those cultivated in the wider region, whilst a range of imported fruits and flavourings were also present. The adoption of new oil crops and new grassland management shows that agricultural innovations were associated with foddering for animals rather than providing food for the proto-urban population. The evidence from Silchester is compared with other archaeobotanical datasets from oppida in Europe in order to identify key trends in agricultural change.

'More-than-human’ resilience(s)? Enhancing community in Finnish forest farms

Community resilience is widely understood as a critical element in the relatively under-explored concept of social resilience. Through engaging with ‘more-than-human’ literatures, a more expansive view of the ‘social’ emerges, which repositions individuals as networked and agency as relational. This moves resilience away from its hegemonic positioning as a neoliberal strategy of individualisation and responsibilisation, with it instead emerging as an everyday ‘doing’ embedded in the human and non-human networks of relationality that we form and are formed by. The paper develops this socio-cultural conceptualisation through an original and empirically grounded discussion of Finnish farm communities and the role of the forest in developing, maintaining and enhancing these essential, connective assemblages. Resilience becomes conceptualised as dynamic, uneven, multiple and contextual performances or resiliences. While this further problematizes the comparative measurement and operationalisation of resilience, its networked and relational nature arguably offers a more inclusive and ethically grounded concept that, furthermore, negates the socio-ecological divide that persists in resilience thinking.

Size matters: body size determines functional responses of ground beetle interactions

Understanding patterns in predator:prey systems and the mechanisms that underlie trophic interactions provides a basis for predicting community structure and the delivery of natural pest control services. The functional response of predators to prey density is a fundamental measure of interaction strength and its characterisation is essential to understanding these processes. We used mesocosm experiments to quantify the functional responses of five ground beetle species that represent common generalist predators of north-west European arable agriculture. We investigated two mechanisms predicted to be key drivers of trophic interactions in natural communities: predator:prey body size ratio and multiple predator effects. Our results show regularities in foraging patterns characteristic of similarly sized predators. Ground beetle attack rates increased and handling times decreased as the predator:prey body-mass ratio rose. Multiple predator effects on total prey consumption rates were sensitive to the identity of the interacting species but not prey density. The extent of interspecific interactions may be a result of differences in body mass between competing beetle species. Overall these results add to the growing evidence for the importance of size in determining trophic interactions and suggest that body mass could offer a focus on which to base the management of natural enemy assemblages.

Concordant Phylogeographies of 2 Malaria Vectors Attest to Common Spatial and Demographic Histories

The phylogeography of South American lineages is a topic of heated debate. Although a single process is unlikely to describe entire ecosystems, related species, which incur similar habitat limitations, can inform the history for a subsection of assemblages. We compared the phylogeographic patterns of the cytochrome oxidase I marker from Anopheles triannulatus (N = 72) and previous results for A. darlingi (N = 126) in a broad portion of their South American distributions. Both species share similar population subdivisions, with aggregations northeast of the Amazon River, in southern coastal Brazil and 2 regions in central Brazil. The average (ST) between these groups was 0.39 for A. triannulatus. Populations northeast of the Amazon and in southeastern Brazil are generally reciprocally monophyletic to the remaining groups. Based on these initial analyses, we constructed the a priori hypothesis that the Amazon and regions of high declivity pose geographic barriers to dispersal in these taxa. Mantel tests confirmed that these areas block gene flow for more than 1000 km for both species. The efficacy of these impediments was tested using landscape genetics, which could not reject our a priori hypothesis but did reject simpler scenarios. Results form summary statistics and phylogenetics suggest that both lineages originated in central Amazonia (south of the Amazon River) during the late Pleistocene (579 000 years ago) and that they followed the same paths of expansion into their contemporary distributions. These results may have implications for other species sharing similar ecological limitations but probably are not applicable as a general paradigm of Neotropical biogeography.

Phytophagous insect fauna tracks host plant responses to exotic grass invasion

The high dependence of herbivorous insects on their host plants implies that plant invaders can affect these insects directly, by not providing a suitable habitat, or indirectly, by altering host plant availability. In this study, we sampled Asteraceae flower heads in cerrado remnants with varying levels of exotic grass invasion to evaluate whether invasive grasses have a direct effect on herbivore richness independent of the current disturbance level and host plant richness. By classifying herbivores according to the degree of host plant specialization, we also investigated whether invasive grasses reduce the uniqueness of the herbivorous assemblages. Herbivorous insect richness showed a unimodal relationship with invasive grass cover that was significantly explained only by way of the variation in host plant richness. The same result was found for polyphagous and oligophagous insects, but monophages showed a significant negative response to the intensity of the grass invasion that was independent of host plant richness. Our findings lend support to the hypothesis that the aggregate effect of invasive plants on herbivores tends to mirror the effects of invasive plants on host plants. In addition, exotic plants affect specialist insects differently from generalist insects; thus exotic plants affect not only the size but also the structural profile of herbivorous insect assemblages.

Consequences of Simulated Loss of Open Cerrado Areas to Bird Functional Diversity

Over the past 35 years, more than two thirds of the Cerrado`s original expanse has been taken by agriculture. Even if some attempts have been made to conserve closed cerrado physiognomies, open cerrado physiognomies, richer in species and more fragile, have been systematically ignored. These open physiognomies are used by almost half of the Cerrado bird species, many of which being endemics. Using data from 11 surveys carried out in Cerrado landscapes, we asked what would happen to bird functional diversity if open cerrado species became extinct. Open cerrado birds would be able to keep on average 59% of the functional diversity. If they became extinct, on average 27% of the functional diversity would be lost. In this case, the remaining functional diversity would be lower than what would be expected by chance in five sites. Although many functions were shared by both open cerrado and forest species, there was some degree of complementarity between them, highlighted by the decrease in functional diversity when the former became extinct. Destruction of open cerrado physiognomies would lead to a habitat simplification, decrease in bird functional diversity, and, ultimately, to a considerable impact on community functioning. Thus, open cerrado physiognomies must receive much more conservation attention than they are currently receiving, because they maintain a high bird functional diversity that would otherwise be considerably diminished Were open cerrado species to become extinct.