Reproducibility of species recognition in modern planktonic foraminifera and its implications for analyses of community structure

Applications of planktonic foraminifera in Quaternary palaeoceanographic and palaeobiological studies require consistency in species identification. Yet the degree of taxonomic consistency among the practitioners and the effects of any potential deviations on community structure metrics have never been quantitatively assessed. Here we present the results of an experiment in taxonomic consistency involving 21 researchers representing a range of experience and taxonomic schools from around the world. Participants were asked to identify the same two sets of 300 specimens from a modern subtropical North Atlantic sample, one sieved at  &gt; 125&thinsp;µm and one at  &gt;  150&thinsp;µm. The identification was carried out either on actual specimens (slide test) or their digital images (digital test). The specimens were fixed so the identifications could be directly compared. In all tests, only between one-quarter and one-eighth of the specimens achieved absolute agreement. Therefore, the identifications across the participants were used to determine a consensus ID for each specimen. Since no strict consensus ( &gt; 50&thinsp;% agreement) could be achieved for 20–30&thinsp;% of the specimens, we used a soft consensus based on the most common identification. The average percentage agreement relative to the consensus of the slide test was 77&thinsp;% in the  &gt; 150&thinsp;µm and 69&thinsp;% in the  &gt; 125&thinsp;µm test. These values were 7&thinsp;% lower for the digital analyses. We find that taxonomic consistency is enhanced when researchers have been trained within a taxonomic school and when they regularly perform community analyses. There is an almost negligible effect of taxonomic inconsistency on sea surface temperature estimates based on transfer function conversion of the census counts, indicating the temperature signal in foraminiferal assemblages is correctly represented even if only two-thirds of the assemblage is consistently identified. The same does not apply to measures of diversity and community structure within the assemblage, and here we advise caution in using compound datasets for such studies. The decrease in the level of consistency when specimens are identified from digital images is significant and species-specific, with implications for the development of training sets for automated identification systems.</p

Environmental Predictors of Diversity in Recent Planktonic Foraminifera as Recorded in Marine Sediments

© 2016 Fenton et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. [4.0 license]. The attached file is the published version of the article

(Table 2) Planktic foraminifera and their diversity indices of sediment surface samples from the Atlantic Ocean

Species distribution patterns in planktonic foraminiferal assemblages are fundamental to the understanding of the determinants of their ecology. Until now, data used to identify such distribution patterns was mainly acquired using the standard >150 µm sieve size. However, given that assemblage shell size-range in planktonic foraminifera is not constant, this data acquisition practice could introduce artefacts in the distributional data. Here, we investigated the link between assemblage shell size-range and diversity in Recent planktonic foraminifera by analysing multiple sieve-size fractions in 12 samples spanning all bioprovinces of the Atlantic Ocean. Using five diversity indices covering various aspects of community structure, we found that counts from the >63 µm fraction in polar oceans and the >125 µm elsewhere sufficiently approximate maximum diversity in all Recent assemblages. Diversity values based on counts from the >150 µm fraction significantly underestimate maximum diversity in the polar and surprisingly also in the tropical provinces. Although the new methodology changes the shape of the diversity/sea-surface temperature (SST) relationship, its strength appears unaffected. Our analysis reveals that increasing diversity in planktonic foraminiferal assemblages is coupled with a progressive addition of larger species that have distinct, offset shell-size distributions. Thus, the previously documented increase in overall assemblage shell size-range towards lower latitudes is linked to an expanding shell-size disparity between species from the same locality. This observation supports the idea that diversity and shell size-range disparity in foraminiferal assemblages are the result of niche separation. Increasing SST leads to enhanced surface water stratification and results in vertical niche separation, which permits ecological specialisation. Specific deviations from the overall diversity and shell-size disparity latitudinal pattern are seen in regions of surface-water instability, indicating that coupled shell-size and diversity measurements could be used to reconstruct water column structures of past oceans

Spatial and economic smart strategies for the 21st-Century metropolitan city of Naples.

The assumption of Neoliberalism in the economy has multiplied exponentially financing speculation, and produced several “distortions” both in the social system and in the job market: the destruction of a welfare program, the attack to the right of the labor market and workers right, the powerful growing of financial institutions supported by the ICT. This means the need to identify a new epistemological approach, suggesting a conceptual framework for ecological economics based on systemic principles of life and a shift from techno-city to a human city. A model, called the homological smart city, could be a new way, based on direct citizen participation, peer-to-peer community, neuroergonomics, biophilic design, and biourban economics. The operational character of this model is explored by analyzing the most recent Italian experiences in reaction to the diffused crisis conditions. Several villages, towns and cities have seen a slow phenomenon of the revival of local communities, for the merit of grassroots’ initiatives of social innovation constituted mostly of young people that, leveraging on their capabilities and a peer-to-peer network supported by the ICT, promote a novel vision for the future of their community, building a more sustainable urban system. Through a change of paradigm, the human being is put at the centre of the system and its designing, considering social innovators as the key actors of change and local assets as the key resources for the implementation of Biourbanism principles. In the above perspective, the experience of a new biourban strategy named “mushrooming”, implemented in Finland, constitutes a good example of practice-oriented to consider diversification as a principle of life in a city and developed by testing with real-life conditions. The Finnish experience was started to build a network to foster interaction between small self-organized co-working communities, by taking into account spatial and economic processes that emerged due to this. These processes were able to activate connected diversification, recognized as a systemic principle of life that fits the context of urban development especially well. The principle of connected diversification drives the methodological process structured for the case study of the Metropolitan City of Naples, one of the 14 Italian metropolitan cities, with a specific attention for the 16 municipalities of the Coast Area. Starting from vulnerability and resilience concepts, the study dealt according to a multi-methodological approach, based on a GeoDesign process supported by multi-criteria analysis, multi-group analysis, and spatial analysis. The elaboration of Spatial Opportunity Maps (SOMs) is the output of a multidimensional evaluation process that leads to the identification of a biourban strategy, characterized by human smart spatial solutions, place-based and situated actions. The enhancement of the coastal area of the Metropolitan City of Naples can be considered as a prerequisite for the activation of a process-oriented to the identification of “homogeneous zones”, conceived not only as areas with similar characteristics but, above all, as territories where it is possible to promote networks of opportunities between the various municipalities and their communities. Cooperation has conceived a source of mutual benefit and involves a mutual convenience, based on the constant construction of bonds and relationships and the interdependence determined by spatial proximity. Economic processes require cooperative-collaborative behaviours between the various components and become increasingly territorialised, and therefore more resilient and, at the same time, less and less associated with the production of negative environmental impact.N/