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This paper will attend to the emergence of the concept of assemblage in human geography and looks towards some vigilant steps we might take in using Deleuze and Guattari's version of it. The paper is in three parts: first, it briefly looks backwards, charting this emergence to the uptake of the work of Gilles Deleuze and Felix Guattari as a counterpoint and extension of the earlier engagement with the concept of the network, primarily in actor-network theory (ANT); second, it makes this argument for being vigilant with assemblages through focusing attention on the tetravalent characteristics of the concept of the Deleuze-Guattarian assemblage, emphasising the way this points to alternative arrays of matter and thought. This segues into the third section, which situates the debates in our contemporary understandings of our technological and biochemical condition. The point being that we need precisely the kind of assemblage thinking proposed by Deleuze and Guattari to seize the agenda on the emergent micro- and eco-logical implications these arrays of matter and thought produce; the agenda proposed is exampled through understanding the assemblage concept through the work of Catherine Malabou on that of plasticity and habit, clear extensions in the 21st century of Deleuze and Guattari's earlier ideas. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to explore the notion of assemblage and how I have deployed it in my work on urban policy mobilities and harm-reduction drug policy. My research entails the detailed tracing of flows of policy knowledge among cities around the world. In detailing and conceptualising these circulations, I am interested in how they are actively and purposively assembled and negotiated in place in productive ways. The paper uses the case of harm reduction - a public health approach to the governance of illicit drug use - as a frame within which to discuss the benefits of assemblage in the study of urban policy-making, urban politics and global-urban connections. [ABSTRACT FROM AUTHOR]

Insects are the most ubiquitous and diverse group of eukaryotic organisms on Earth, forming a crucial link in terrestrial and freshwater food webs. They have recently become the subject of headlines because of observations of dramatic declines in some places. Although there are hundreds of long‐term insect monitoring programs, a global database for long‐term data on insect assemblages has so far remained unavailable. In order to facilitate synthetic analyses of insect abundance changes, we compiled a database of long‐term (≥10 yr) studies of assemblages of insects (many also including arachnids) in the terrestrial and freshwater realms. We searched the scientific literature and public repositories for data on insect and arachnid monitoring using standardized protocols over a time span of 10 yr or longer, with at least two sampling events. We focused on studies that presented or allowed calculation of total community abundance or biomass. We extracted data from tables, figures, and appendices, and, for data sets that provided raw data, we standardized trapping effort over space and time when necessary. For each site, we extracted provenance details (such as country, state, and continent) as well as information on protection status, land use, and climatic details from publicly available GIS sources. In all, the database contains 1,668 plot‐level time series sourced from 165 studies with samples collected between 1925 and 2018. Sixteen data sets provided here were previously unpublished. Studies were separated into those collected in the terrestrial realm (103 studies with a total of 1,053 plots) and those collected in the freshwater realm (62 studies with 615 plots). Most studies were from Europe (48%) and North America (29%), with 34% of the plots located in protected areas. The median monitoring time span was 19 yr, with 12 sampling years. The number of individuals was reported in 129 studies, the total biomass was reported in 13 studies, and both abundance and biomass were reported in 23 studies. This data set is published under a CC‐BY license, requiring attribution of the data source. Please cite this paper if the data are used in publications, and respect the licenses of the original sources when using (part of) their data as detailed in Metadata S1: Table 1. [ABSTRACT FROM AUTHOR]

Whilst greatly valuing recent critiques of the vertical imaginary and reified ontology of scale theory, and of the unfettered flows of network theory, this paper argues against a human geography without scale. Rather, four propositions from the theoretical literature are used to provide a tool-kit to analyse the practical negotiation of scalar politics, namely that: scales should be considered as effects, not frames or structures, of practice; networks must be considered in all their complexity and heterogeneity; networks can be interpreted as assemblages, the more re-territorialising and re-scaling of which can be analysed as apparatuses; and that state apparatuses work to create the impression that scales are ahistorical, hierarchical and possess exclusive relationships. These propositions are used to explore a period of history when the scalar constitution of the world was under intense debate. The interwar era saw the imperial scale clash with that of the international, both as ideological worldviews, and as a series of interacting institutions. The assemblages of internationalism and imperialism were embodied by apparatuses such as the League of Nations and the colonial Government of India respectively. Attempts by the League to encourage the abolition of tolerated brothels in an attempt to reduce the trafficking of women and children led to intense debates between the 1920s and 1930s over what constituted the legitimate domains of the international and the ‘domestic’. These explicitly scalar debates were the product of League networks that threatened the scalar sovereignty of the Raj, most directly through the travelling Commission of Enquiry into Traffic in Women and Children in the East in 1931. [ABSTRACT FROM AUTHOR]

Mobile species are particularly affected by artificial barriers requiring large investments to restore connectivity. However, few large‐scale, long‐term studies have investigated the ecological outcomes of restoring connectivity for these species. Our study, spanning 15–20 years, quantified response trajectories, which represent temporal trends following disturbance, of three native salmonids colonizing 20 km of protected habitat following restoration of fish passage at Landsburg Dam, Cedar River, WA, in 2003. Built in 1901, the dam blocked the upriver movement of native anadromous coho and Chinook salmon and nonanadromous mountain whitefish for 102 years. Restoration effectiveness was also assessed by comparing temporal trends in freshwater productivity of juvenile coho and Chinook salmon in the Cedar River after restoration to a nearby undammed subbasin. We also compared summer densities of juvenile coho and Chinook salmon, and mountain whitefish above the dam measured a decade after restoration to undammed reference systems. Anadromous salmon and nonanadromous mountain whitefish populations increased linearly or nonlinearly following restoration. The positive, asymptotic response represented by adult Chinook salmon counts indicates a slowing in population recovery rate, plateauing a decade after restoration. In contrast, annual abundance of adult coho salmon increased at a constant rate, indicating additional capacity 15 years post‐restoration. Salmonid compositional diversity, driven largely by juvenile coho salmon, also increased nonlinearly, plateauing in a decade. We observed substantial spatial variation in the temporal response, as juvenile coho salmon and mountain whitefish population expansion slowed linearly with upstream distance from the restoration site. There was evidence that some of the annual variation in salmonid biomass in summer was a result of discharge variability in winter and spring, with biomass declining as flow variability increased. Species reintroduction and establishment had no discernible effect on stream‐rearing salmonids living above the dam before restoration, while increasing coho freshwater productivity at the subbasin scale. Results from our study showed recolonization by three mobile species, each with a unique life history, takes at least a decade or more and was dependent on species and life stage, size of the spawning population, distance from restoration site, and annual variability in streamflow. [ABSTRACT FROM AUTHOR]

Anthropogenic debris contaminates marine habitats globally, leading to several perceived ecological impacts. Here, we critically and systematically review the literature regarding impacts of debris from several scientific fields to understand the weight of evidence regarding the ecological impacts of marine debris. We quantified perceived and demonstrated impacts across several levels of biological organization that make up the ecosystem and found 366 perceived threats of debris across all levels. Two hundred and ninety-six of these perceived threats were tested, 83% of which were demonstrated. The majority (82%) of demonstrated impacts were due to plastic, relative to other materials (e.g., metals, glass) and largely (89%) at suborganismal levels (e.g., molecular, cellular, tissue). The remaining impacts, demonstrated at higher levels of organization (i.e., death to individual organisms, changes in assemblages), were largely due to plastic marine debris (>1 mm; e.g., rope, straws, and fragments). Thus, we show evidence of ecological impacts from marine debris, but conclude that the quantity and quality of research requires improvement to allow the risk of ecological impacts of marine debris to be determined with precision. Still, our systematic review suggests that sufficient evidence exists for decision makers to begin to mitigate problematic plastic debris now, to avoid risk of irreversible harm. [ABSTRACT FROM AUTHOR]

Although global assessments provide evidence of biodiversity decline, some have questioned the strength of the evidence, with local assemblage studies often showing a more balanced picture of biodiversity change. The multifaceted nature of biodiversity and imperfect monitoring datasets may partially explain these findings. Here, using an extensive dataset, we find significant biodiversity loss in the native avifauna of the European Union (EU). We estimate a decline of 17–19% in the overall breeding bird abundance since 1980: a loss of 560–620 million individual birds. Both total and proportional declines in bird numbers are high among species associated with agricultural land. The distribution of species' population growth rates (ln) is centered close to zero, with numerical decline driven by substantial losses in abundant species. Our work supports previous assessments indicating substantial recent biodiversity loss and calls to reduce the threat of extinctions and restore species' abundances, for the sake of nature and people. [ABSTRACT FROM AUTHOR]

Ecosystems can respond in a variety of ways to the same agent of disturbance. In some contexts, fire causes large and long‐lasting changes to ecological communities. In others, fire has a limited or short‐lived impact on assemblages of animals and plants. Understanding why this occurs is critical if we are to manage these kinds of disturbances across the globe. A recent synthesis proposed that these seemingly idiosyncratic responses to fire can be understood in the context of habitat openness pre‐disturbance. Assemblages in open habitats should respond less to a single fire event that those in closed habitats. We provide a test of this hypothesis by examining the response of ant (Hymenoptera: Formicidae) communities to large‐scale fire events in three habitats of different natural canopy openness on the Peloponnese peninsula in Greece. We also test the hypothesis that assemblage responses to fire are trait dependent. Fire simplifies the physical structure of the environment, increases insolation, and limits opportunities for ants to exploit herbivorous feeding strategies. Consequently, we predict that ants will face a strong environmental filter between unburnt and recently burnt plots, which will be reflected in their functional morphology. Our analysis shows that burnt plots have more individual ants, more species and an almost complete compositional change relative to unburnt plots. These changes do not depend on initial canopy openness. Rather, we suggest that openness must be interpreted relative to the study taxon; for ants, openness should be measured closer to the ground level. In our study, ground‐level openness does not vary across the plots, which may explain the results. Furthermore, ants in burnt plots are significantly larger, have relatively longer legs, relatively longer mandibles, and more elongate heads. This morphotype fits with our prediction of ants that can move and feed successfully in the burnt micro‐landscape. Ultimately, more work is needed to fully explore the relationship between habitat openness and the response to fire. Our results showing a filtered set of ant morphologies in burnt environments suggest that ant traits may offer a further way forward to understand the faunal response to fire and disturbance in general. [ABSTRACT FROM AUTHOR]

Aim: Body size frequency distributions are often skewed to the right, with a greater frequency of small‐sized species. Right skewness can appear when speciation is biased towards small species and extinction towards large ones. In contrast, limits imposed by environmental constraints will select taxa to co‐occur in assemblages and can modify size distributions to the left or to the right. We analysed whether the shape of size distributions of anurans is related to diversification rates and how the environment might also be creating the observed patterns. Location: The Western Hemisphere. Time period: Current. Major taxa studied: Anurans. Methods: We computed diversification rates from a dated phylogeny and obtained data for body size, spatial distribution and the climate (annual temperature, potential evapotranspiration and normalized difference vegetation index) inhabited by 2,598 anuran species to analyse the relationship between diversification rates and body size. We then used an assemblage‐based approach to test whether the climate is acting together with species evolutionary history to generate skewed distributions of body sizes at local sites. Results: Skewness was positively correlated with size‐biased speciation and extinction, whereas it was negatively correlated with net diversification. After the inclusion of environmental predictors, the explanatory power of our models increased significantly. When ranking the predictors, evolutionary rates remained first, followed by a secondary role of environmental variables. Main conclusions: Despite the high frequency of right‐skewed body size distributions, anuran assemblages of the New World showed a variation of skewness that can be explained by faster net diversification (speciation minus extinction) at modal sizes. We conclude that size‐biased evolutionary rates and the environment both have a role in defining the proportion of small and large sizes at local scales. [ABSTRACT FROM AUTHOR]

Aim: Crayfish are globally diverse and one of the most important taxa in North American streams. Despite their importance, many species are of conservation concern and efforts to improve conditions are limited. Here, we address two major impediments to improving conditions: (a) our lack of knowledge of the interplay among natural landscape and human‐induced changes; and (b) a very limited understanding of how species interactions affect overall crayfish distributions. Location: Ozark Highlands ecoregion, USA. Methods: We used both existing data and field‐collected data to examine the relationships between 12 Faxonius species and physicochemical variables at multiple spatial scales. Data were analysed using a generalized linear mixed model. After fitting our environmental variables, we also considered possible relationships between species considered strong competitors and species occurrence. Results: Our results indicated that elevation, lithology, an interaction between drainage area and anthropogenic disturbance, and the presence of strong competitors were associated with Faxonius occurrences. Faxonius occurrences were associated with assemblage‐structuring variables: lithology and elevation. More interestingly, we found several patterns of interactions between drainage area and disturbance. The most common pattern among several species was a decline in occurrence in larger drainages when disturbance was high; however, longpincered crayfish (Faxonius longidigitus) was more likely to occupy large drainages as disturbance increased. Additionally, the presence of species considered strong competitors resulted in lower occurrence probability for many species, including two of the species classified as competitors. Main conclusions: In addition to identifying the relationships between native species and assemblage‐structuring variables, we show how the probability of species occurrences relate to interactions between disturbance and natural landscape features. Further, our results suggest competitor presence also plays a role in structuring distributions at the stream segment scale. Our findings emphasize the value of considering both competitor presence and interactions among landscape variables and disturbances in structuring crayfish assemblages. [ABSTRACT FROM AUTHOR]

Community ecology is an inherently complicated field, confounded by the conflicting use of fundamental terms. Nearly two decades ago, Fauth et al. (1996) demonstrated that imprecise language led to the virtual synonymy of important terms and so attempted to clearly define four keywords in community ecology; ' community,' ' assemblage,' ' guild,' and ' ensemble'. We revisit Fauth et al.'s conclusion and discuss how the use of these terms has changed over time since their review. An updated analysis of term definition from a selection of popular ecological textbooks suggests that definitions have drifted away from those encountered pre-1996, and slightly disagreed with results from a survey of 100 ecology professionals (comprising of academic professors, nonacademic PhDs, graduate and undergraduate biology students). Results suggest that confusion about these terms is still widespread in ecology. We conclude with clear suggestions for definitions of each term to be adopted hereafter to provide greater cohesion among research groups. [ABSTRACT FROM AUTHOR]

Three different versions of assemblage (Deleuzian, actor-network theory and Haraway's companionship) are discussed in terms of the insights they offer into spatial relations between life science, medicine and society. Using the example of a proposal to turn Iceland into an island laboratory for gene discovery research, I ask how assemblages gain friction and tenacity in the world, especially if we accept the post-structuralist insistence on the fragility of any seemingly fixed, isolated and bounded construction of space. Why did so many people (including academics) buy in to the idea of Iceland as an ideal genetic laboratory? How were the pieces of that island laboratory made to fit together and at what price? [ABSTRACT FROM AUTHOR]

This commentary explores how assemblage thinking might reconfigure understandings of the spatial constitution of articulation. The first section critiques the accounts of the relationalities of political activity associated with site ontology. This argument is illustrated by a brief discussion of the role of West African and Caribbean seafarers in shaping translocal anti-colonial networks in the 1930s. The second section uses assemblage thinking to inform a processual, relational reworking of articulation as bearing on the negotiation of multiple political trajectories. I conclude that this involves dislocating some key ways of theorising both assemblage and articulation. [ABSTRACT FROM AUTHOR]

In this commentary I would like to offer some reflections on the Deleuzian concept of 'assemblage' (agencement) from the perspective of my grounding in 'governmentality studies' and, secondly, on the latter's central concern with the concept of the security 'apparatus' (dispositif). I would like to suggest that the two be thought of dialectically, both as concepts and as actually-existing things in the world. After outlining my use to date of these concepts, and their deployment in my research into colonial India, I will counterpoise Giorgio Agamben's and Giles Deleuze's reflections on Michel Foucault's use of the term dispositif/apparatus. Deleuze's obvious and acknowledged indebtedness to Foucault's work, but his explicit re-rendering of the Foucauldian interest in order with the Deleuzian conceptualisation of dis-order, will be used to conclude with some methodological suggestions regarding how Deleuze and Foucault, agencement and dispositif, assemblages and apparatuses, can and should be thought together. [ABSTRACT FROM AUTHOR]

This article explores the fluidities and stabilities of urban materiality by looking at the ongoing emergence of a 300-year-old church in central Manchester. The notion of assemblages is utilised to investigate how places, such as the building featured here, are simultaneously destroyed and altered by numerous agencies, and stabilised by repair and replacement building material. By examining the vital properties of stone and the particular non-human agents that act upon the stony fabric of the building, I explore some of the processes that render matter continuously emergent. I subsequently consider the consequences of these material transformations by looking at how they promote the enrolment of two human processes of spatial (re)ordering, the forging of connections between the city and sites of stone supply, and the changing and contested process of repair and maintenance. I argue that by acknowledging complexity, historical depth and geographical scale, non-human and human entanglements, and ambiguity, we might write accounts that do justice to the emergence, contingency and unpredictability in a world of innumerable agencies. [ABSTRACT FROM AUTHOR]

Abstract Aim To (1) describe termite functional diversity patterns across five tropical regions using local species richness sampling of standardized areas of habitat; (2) assess the relative importance of environmental factors operating at different spatial and temporal scales in influencing variation in species representation within feeding groups and functional taxonomic groups across the tropics; (3) achieve a synthesis to explain the observed patterns of convergence and divergence in termite functional diversity that draws on termite ecological and biogeographical evidence to-date, as well as the latest evidence for the evolutionary and distributional history of tropical rain forests. Location Pantropical. Methods A pantropical termite species richness data set was obtained through sampling of eighty-seven standardized local termite diversity transects from twenty-nine locations across five tropical regions. Local-scale, intermediate-scale and large-scale environmental data were collected for each transect. Standardized termite assemblage and environmental data were analysed at the levels of whole assemblages and feeding groups (using components of variance analysis) and at the level of functional taxonomic groups (using correspondence analysis and canonical correspondence analysis). Results Overall species richness of local assemblages showed a greater component of variation attributable to local habitat disturbance level than to region. However, an analysis accounting for species richness across termite feeding groups indicated a much larger component of variation attributable to region. Mean local assemblage body size also showed the greater overall significance of region compared with habitat type in influencing variation. Ordination of functional taxonomic group data revealed a primary gradient of variation corresponding to rank order of species richness within sites and to mean local species richness within regions. The latter was in the order: Africa... [ABSTRACT FROM AUTHOR]

In this brief conclusion to the special section on 'Assemblage and Geography' we reflect on the promises and challenges of assemblage thinking in the context of contemporary geographical thought. We draw out five issues for further discussion; ontological diversity, formation, the non-relational, newness and method. [ABSTRACT FROM AUTHOR]

Understanding how novel biological assemblages are structured in relation to dynamic environmental regimes remains a central challenge in ecology. Demographic approaches to modeling species assemblages show promise because they seek to represent fundamental relationships between population dynamics and environmental conditions. In dryland rivers, rapidly changing climate conditions have shifted drought and flooding regimes with implications for fish communities. Our goals were to (1) develop a mechanistic multispecies demographic model that links native and nonnative species with river flow regimes, and (2) evaluate demographic responses in population and community structure to changing flow regimes. Each fish species was represented by a stage‐structured matrix, and species were coupled together into a multispecies framework through density‐dependent relationships in reproduction. Then, community dynamics were simulated through time using annual flow events classified from gaged streamflow data. We parameterized the model with vital rates and flow–response relationships for a community of native and nonnative fishes using literature‐derived values. We applied the simulation model to the Verde River (Arizona, USA), a major tributary within the Colorado River Basin, for the past half century (1964–2017). Model validation revealed a match between model projections and relative abundance trends observed in a long‐term fish monitoring dataset (1994–2008). At the beginning of the validation period (1994), model and survey observations showed that native species comprised approximately 80% of total abundance. Model projections beyond the survey data (2008–2017) predicted a shift from a native dominant to a nonnative dominant assemblage, coinciding with increasing drought frequency. Trade‐offs between native and nonnative species dominance emerged from differences in mortality in response to the changing sequence of major flow events including spring floods, summer high flows, and droughts. In conclusion, the demographic approach presented here provides a flexible modeling framework that is readily applied to other stream systems and species by adjusting or transferring, when appropriate, species vital rates and flow‐event thresholds. [ABSTRACT FROM AUTHOR]