Molluscan assemblages of seagrass-covered and bare intertidal flats on the Banc d'Arguin, Mauritania, in relation to characteristics of sediment and organic matter

The Banc d'Arguin, a non-estuarine area of shallows and intertidal flats off the tropical Saharan coast of Mauritania, is characterised by extensive intertidal and subtidal seagrass beds. We examined the characteristics of intertidal seagrass (Zostera noltii) meadows and bare areas in terms of the presence and abundance of molluscs (gastropods and bivalves). To explain observed differences between molluscan assemblages in seagrass and bare patches, some aspects of the feeding habitat (top-5 mm of the sediment) and of food (organic materials) of molluscs were examined. The novelty of this study is that phytopigments were measured and identified to assess source and level of decay (freshness) of organic material in the sediment and to study their importance as an explanatory variable for the distribution of molluscs. Over an area of 36 km² of intertidal flats, at 12 sites, paired comparisons were made between seagrass-covered and nearby bare patches. Within seagrass meadows, dry mass of living seagrass was large and amounted to 180 ±10 g AFDM m^− 2 (range 75–240). Containing twice the amount of silt per unit dry sediment mass, seagrass sediments were muddier than bare areas; the relative amount of organic material was also larger. The total number of species of bivalves and gastropods amounted to 27, 14 of which were found only in seagrass areas, 4 only in bare and 9 in both types of habitat. Among the three numerically most abundant species, the bivalves Anadara senilis, Dosinia hepatica and Loripes lacteus, the first was numerically most abundant in bare and the other two in seagrass-covered areas. Bare intertidal areas had greater mean total biomass of molluscs (80.5 g AFDM m^− 2) than seagrass meadows (30.0 g AFDM m^− 2). In both habitats, the bulk of the biomass was made up by A. senilis. Excluding this species, bare mudflats contained on average only 3.1 g AFDM m^− 2 and seagrass meadows 6.9 g AFDM m^− 2. As compared to previous surveys in 1980–1986, the biomass of A. senilis had increased almost 10-fold and D. hepatica, previously found in very small numbers, had become the most numerous species. However, the total biomass excluding that of A. senilis was similar. Concentrations of phytopigments were similar to those observed at temperate mudflats, indicating that the Banc d'Arguin might not be as oligotrophic as previously thought. Per unit of dry sediment mass, smaller amounts of phytopigments were found in bare than in seagrass areas. Per unit of dry organic material, bare sediments contained most (fresh) phytopigments. This suggests that in seagrass-covered meadows the organic material is more degraded than in bare sediments. Overall, the composition of phytopigments, quite surprisingly, indicated a benthic-diatom-dominated trophic system. Multivariate statistics revealed that patterns of zoobenthic assemblages were correlated with patterns of a combination of four environmental parameters: grain size of the sediment, amount of fresh phytopigments and amounts of leaves and roots of seagrass.     

Tiny trees for trendy produce: Dwarfing technologies as assemblage actors in orchard economies

Apple varieties boom and bust as the vogue for new flavors cycle through the market. Dwarfing rootstocks, an old but freshly blossoming orchard technology, allows growers to intervene in trees in new ways and keep up with shifts in consumer demand. They cultivate customization in apple orchards and facilitate emerging neoliberal trends in food systems. However, the rootstocks do more than entrench actors further into the whims of the market—they also shape economic agency in ways that have multiple expressions. Drawing on work on actor-networks and assemblages, this paper considers how technologies play a role in contemporary food politics through their material characteristics and the performances they inspire. Using apple production in the American Midwest as a case study, this paper discusses the ways that rootstock technologies both reproduce current power structures and conventional organizational forms in food, while providing a platform for an alternative type of assemblage. In doing so, it contributes theoretically to conversations about the role of materials in economic politics and substantively to an optimistic vision of the future of food.     

Beating words to life: subtitles,assemblage(s)capes,expression

Ostensibly, subtitles in films serve as linguistic approximations of meaning. Expectedly then, much of the debate surrounding subtitling has been concerned with representational accuracy, fidelity and authenticity. In this article I argue that by encountering subtitles as affective bodily expressions, as opposed to approximate representations of pre-existent meanings or intentions, filmic experiences may be(come) transformed and differently transformational. As a result, meaning and accuracy in subtitles as superimposed signifiers or static representations become secondary to subtitles as spatially affective- and expressive-movements intimately part of filmic scapes. The creative use of subtitling in Bekmambetov’s Russian language film Night Watch (Nochnoy dozor; 2006 [2004]) is discussed.

Dangerous assemblages: Salts,trihalomethanes and endocrine disruptors in the water palimpsest of the Llobregat River,Catalonia

Water flows through time are connected to specific instances of socionatural and sociotechnical assemblages of human and non-human components. We propose the concept of “water palimpsest” in order to characterize the complex histories of chemical and metabolic alterations embodied in water flows, potentially disruptive for humans and other living beings. Through the concept of palimpsest we interpret the configuration of water flows as constantly evolving towards new patterns maintaining at the same time traces of past mixtures. In order to decipher water pollution by means of a political ecology approach we argue that it is necessary to characterize the historical contours under which certain substances in river waters appear, interact and become hazardous. Engaging critically with literature on assemblages but also with chemical and epidemiological scientific literature, and drawing from archival and oral sources, we provide an account of historically produced pollution in the waters of Llobregat River (Catalonia) by unravelling the assemblages that shape the water palimpsest in this river. In parallel, we narrate the advances in instrumentation and analysis which permitted to detect and measure substances beyond recognition by human senses and preceded legal regulations on pollutants, starting from milligrams and (thus far) arriving at nanoscales. Focusing on the emergence of three typologies of pollutants – salts, trihalomethanes (THMs) and endocrine disruptors (EDs) – we unveil how these three assemblages embody specific instances of Llobregat socioenvironmental history, pointing towards a palimpsest characterized by increasing levels of complexity and uncertainty. The concept of water palimpsest allows us to incorporate non-human agency into the analysis of water quality and to infuse political ecology with materiality and thus with a (largely missing) focus on physicochemical and biological processes.     

川西北早志留世陆源碎屑──碳酸盐混积缓坡

研究区位于扬子地块西北缘，由一套巨厚的页岩、泥岩层夹生物礁及透镜状和不规则层状风暴生屑灰岩、瘤状灰岩组成。根据区内特征的岩石类型及其组合、分布和相应的化石生态，作者认为本区兰多维列期至早温洛克期时为一典型的陆源碎屑－－碳酸盐混积均斜缓坡，并且从浅到深划分为滨岸、浅缓坡、深缓坡及盆地等亚环境。滨岸区位于潮间带，以潮坪碳酸盐岩为代表；浅缓坡位于浪基面至风暴浪基面之间，岩性组合为Ａ、Ｂ类风暴岩，Ａ、Ｂ类瘤状灰岩、生物礁灰岩及粘结岩；深缓坡位于风暴浪基面至最大风暴浪基面之间，岩性以Ｄ、Ｅ类风暴岩、Ｃ类瘤状灰岩及泥页岩组合为特征；盆地处于最大风暴浪基面之下，为黑色泥页岩沉积。结合早志留世时全球冰川作用，文中讨论了海平面变化的原因及对环境的影响。     

Climate characteristics of the eastern Mongolian Plateau,China during the early Early Cretaceous (145–132 Ma): Palynological evidence from the Tongbomiao Formation in Well Hong-6, Hailar Basin

This study identified two palynological assemblages, namely Bayanhuasporites-Cycadopites-Protoconiferus and Cicatricosisporites-Cedripites-Perinopollenites, in the Tongbomiao Formation in the Hongqi Sag in the Hailar Basin, Inner Mongolia, China for the first time. The former is distributed in the lower part of the Tongbomiao Formation and is characterized by abundant gymnosperm pollen and diverse fern spores. Among them, the gymnosperm pollen is dominated by Paleoconifer (4.98%–31.62%) and Cycadopite (8.55%–25.23%) pollen grains and also includes other pollen grains such as Classopollis, Parcisporites, Erlianpollis, Callialasporites, and Jiaohepollis. The fern spores in the former palynological assemblage contain Bayanhuasporite (0–8.96%), Granulatisporites (0.93%–6.97%), and some important Cretaceous genera, such as Cicatricosisporites, Concavissimisporites, Densoisporites, Hsuisporites, Foraminisporis, and Leptolepidites. The Cicatricosisporites-Cedripites-Perinopollenites palynological assemblage is distributed in the upper part of the Tongbomiao Formation. Gymnosperm (77.30%), Pinaceae (31.9%), and Paleoconiferus (19.02%) pollen predominate this palynological assemblage, and Quadraeculina, Erlianpollis, and Jiaohepollis pollen are also common in this assemblage. The fern spores in this palynological assemblage include abundant Cicatricosisporites (4.29%). Besides, Concavissimisporites, Aequitriradites, and Leptolepidites are also common in this palynological assemblage. No angiosperm pollen has been found in both palynological assemblages. The identification of both palynological assemblages provides important evidence for the biostratigraphic correlation between the Hailar Basin and its adjacent areas. It also enables the reconstructions of the Berriasian-Valanginian (Early Cretaceous) vegetation and the paleoclimate on the eastern Mongolian Plateau during 141–132 Ma. The vegetation reconstructed on the palynological data of the represented by Hailar Basin in eastern Mongolian Plateau (141.6–141.4 Ma), form conifer forest or conifer broad-leaved mixed forest to conifer forest with shrubs and grassland, the climate belongs to warm temperate and warm-subtropicalt, the highest temperature is estimated to reach 35–38°C. Form 132.3 Ma, the vegetation type is conifer forest, and its paleoclimate is sub-humid warm temperate, the highest temperature is estimated to reach 24–29°C.©2022 China Geology Editorial Office.     

Late Mesozoic bivalve faunas from the Tetori Group,Japan

The Tetori Group of Japan ranks amongst the more important Upper Mesozoic strata in East Asia, with common animal and plant fossils throughout and is well suited for analyses of the links between environmental changes and the various animal and plant fossil assemblages. Three marine transgressions (i. e., Bathonian–Oxfordian, Tithonian–Berriasian and Hauterivian–Barremian in age) have been recognized in the Tetori Group, based on ammonite index taxa. These pulses are also reflected in bivalve faunas which comprise, 81 species in 65 genera (marine taxa) and 16 species in 13 genera (non-marine taxa). Many of these are considered as endemic species to the Tetori Group. In view of the fact that the occurrence of non-marine taxa was primarily controlled by environmental conditions, these do not constitute chronological indices. The faunal composition of the first marine transgressive phase is similar to that found elsewhere in southeast Asia, while that of the second one resembles both that of southeast Asia and of northeast China and Far East Russia. Assemblages of the third phase are similar to those of Heilongjiang, northeast China. Currents from the equator and high-latitudes explain these similarities.     

Marine-space assemblages: Towards a different praxis of fisheries policy and management

In this paper, we discuss the intent and purpose of Magnuson-Stevens Fishery Conservation Management Act/National Standard 8 and examine how it reinforces problematized conceptualizations of marine-space(s). We then discuss shifts in sensibilities around marine-space, especially with concern to notions of fishing communities and their inclusion in planning and management processes. Through this, we underscore a problematic pervasive in conceptual models used to account for relations between humans and marine-spaces and how this contributes to failures to fulfill regulatory responsibilities to fishing communities. We then draw on new materialist insights into assemblages and affect and emotion to offer alternative ways to think about, research, approach, and manage marine-spaces through more nuanced and informed considerations of their broad, complex, and ever-present human and socio-cultural components.     

Hydroid assemblages from the Southwestern Atlantic Ocean (34–42° S)

This paper provides updated taxonomic knowledge about hydrozoan species and provides ecological information including geographical and bathymetric distributions and biological substrata for the various hydroid assemblages from the Sub-Antarctic Biogeographical Region, mainly Buenos Aires and the Uruguayan coasts. Five of the 41 species found are new records for the study region. Thirty-one species (75.6%), all found at depths of less than 80 m, have cosmopolitan distributions. Biodiversity decreased markedly below 80 m depth, where nine species (≈22%) distributed in the Southern hemisphere and one endemic species (2.4%) were found. Most species were non-specific epizoites, occurring on diverse substrata. A non-parametric multivariate similarity analysis revealed nine species groups that were correlated with large-scale and local oceanographic patterns and with the availability of suitable substrata. The main hydroid substrata for eight of the groups were cnidarians, molluscs (mainly blue mussels), quartzite rocks and sponges. In a single group found in Patagonian scallop beds, the main biological substrata were polychaete tubes, other hydroids and scallops.     

Respatialization and local protest strategy formation: Investigating high-speed rail megaproject development in the UK

Understanding spatial conceptions is critical to the analysis of local protest strategy formation. Spatialities provoke inquiry into the drivers that may prompt local actors to adhere to particular strategies, and the implications this has on forms of contestation and the way protest is organized. It is argued that local protest can ‘respatialize’ when actors are embedded in social movements and translocal assemblages associated with controversy over development, and that this warrants reconsidering the role of ‘place’. A case study of a proposed megaproject framed in the national interest – a high-speed rail network called HS2, in the United Kingdom – is used to investigate local protest respatialization. Fieldwork was conducted in the Chilterns, an area of high scenic beauty which will be adversely impacted by HS2. The results show how the perceived need to respatialize protest away from the local to the national domain reconfigures debate to focus primarily on economic issues. Respatialization also has implications for the dynamics of protest assemblages with unlikely alliances developing around a need to engage with or engender debate in the national polity. It is concluded that local actors may opt to respatialize their protest in response to their interaction with social movements and protest assemblages that disengage from specific place-based interests. The paper recommends that future research on the geographies of social action take forward spatialization as a powerful lens for investigating protest strategy formation.