Limits Of Europe Research Articles

Watering the trees for the forest: Drought alleviation in oaks and pines by ancestral ditches

Traditional ditches (“acequias” in Spanish) derive meltwater and infiltrate groundwater providing ecological services downstream in the semi-arid Sierra Nevada range (SE Spain). Therefore, they may act as a nature-based solution by alleviating drought stress in trees growing near ditches by enhancing growth and reducing their intrinsic water-use efficiency (iWUE). Such a mitigation role of acequias is critical given that some oak (Quercus pyrenaica) and pine (Pinus sylvestris) stands reach their xeric distribution limits in Europe. We compared tree-ring width data and wood δ13C, a proxy of iWUE, in oak and pine stands located near or far (control) from ditches with different infiltration capacity in two watersheds. We assessed how trees responded to climate data, drought stress, and vegetation greenness through correlations and resilience indices. Oak trees located near ditches grew more and responded less to precipitation, soil moisture, a drought index, and greenness than control trees. In pines, we did not find this pattern, and ditch trees grew more than control trees only during an extremely dry year (1995). Climate-growth correlations suggested a longer growing season in ditch pines. Growth of ditch oaks from the “Acequia Nueva” (AN), with high infiltration capacity, responded more to autumn soil moisture and showed the lowest δ13C. Growth was enhanced by cool-wet spring conditions in pines and also by warm-wet conditions in the prior winter in the case of oaks. Control trees showed lower resistance to drought. Control trees presented higher wood δ13C values except for old oaks from the “Acequia Grande” (AG) site which may show long-term acclimation. Traditional ditches alleviate drought stress in oak and pine stands subjected to regional xeric climate conditions.

Review of City-Wide 30 km/h Speed Limit Benefits in Europe

To date, more and more European cities are systematically working to expand the proportion of their street network with a speed limit of 30 km/h. This paper endeavored to assess the effectiveness of city-wide 30 km/h speed limits in Europe. In an effort to condense research outputs, a quantitative approach along with qualitative assessments were implemented. This study described the changes in safety, environment, energy, traffic, livability, and health before and after the phased implementation of city-wide 30 km/h speed limits. The systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Results from 40 different cities across Europe, including Brussels, Paris, and Zurich, indicated that reductions in speed limits improved road safety by decreasing the likelihood of crash risk and the severity of crashes that do occur. On average, the implementation of 30 km/h speed limits in European cities demonstrated a 23%, 37%, and 38% reduction in road crashes, fatalities, and injuries, respectively. Lower speed limits also yielded environmental benefits, with emissions decreasing on average by 18%, noise pollution levels by 2.5 dB, and fuel consumption by 7%, indicating enhanced fuel efficiency and reduced environmental impact. Encouraging citizens to embrace walking, cycling and utilizing public transit services can further contribute to a safer and environmentally sustainable urban environment.

Cozy den or winter walk: the effects of climate and supplementary feeding on brown bear winter behavior

AbstractHibernation is a key adaptation for coping with unfavorable climatic conditions and low food availability in areas with severe winter conditions. While understanding the physiology and phenology of this adaptation has received considerable attention, comparatively little information is available on how hibernation will be affected by changing climate conditions. We used GPS telemetry data from 20 free‐ranging brown bears monitored over 31 winters between 2007 and 2022, to identify behavioral strategies of bears during winter. We applied behavioral change point analysis to quantify brown bears’ hibernation phenology in a population close to the bear's southern latitudinal range limit in Europe where supplementary food is available to bears year‐round. We observed winter behavior patterns that varied across age and reproductive classes but also within individuals between winters. Among 31 winter events, we registered six cases in which bears exhibited a single hibernation/stationary period and 19 events where hibernation was split into up to five stationary periods. Moreover, six winter events did not show behaviors consistent with hibernation and individuals remained partly or completely active throughout winter. The movement of these active bears decreased with increasing snow depth. In addition, these winter‐active bears showed higher fidelity to supplementary feeding sites during the winter period compared to the rest of the year. Our data suggest that an abundance of human‐provided food resources during winter may facilitate the emergence of different wintering strategies in brown bears. Furthermore, supplemental feeding sites in combination with predicted mild winters and prolonged natural food availability suggest that the use of hibernation as an energy‐saving strategy to overcome severe environmental conditions may decrease in the future.

The northern wheatear is reducing its distribution in its southernmost European range and moving to higher altitudes

Under the current pattern of climate change, mountain bird populations are generally shifting their ranges to higher elevations, tracking their climatic optima. Nevertheless, space limitations at high altitudes constrain mountain species' resilience to climatic change, making them particularly vulnerable. In extreme cases, the climatic niche of some species can move beyond mountaintops, ultimately driving such species to extinction. This study presents the case of the northern wheatear Oenanthe oenanthe in mainland Spain and compares its breeding distribution from 2003 to 2022. Spain, where the species mostly occupies mountain areas, represents its southernmost distribution limit in Europe. We built environmental favourability models using information from the two most recent Spanish bird atlases and a set of climatic, topographic, human activity and lithological variables to determine the factors affecting the occurrence of the species. The influence of climate compared to all other factors was obtained using variation partitioning analysis. The northern wheatear has suffered a strong reduction (67%) in occupied areas and also in favourability throughout mainland Spain (especially in the south) where climate change may have far‐reaching consequences, including local extinctions. Climate explained more than 90% of the variation in the model obtained for 2022. Interestingly, the occupied areas were, on average, 100 m higher in 2022 than in 2003. If the effects of climate warming persist, the northern wheatear will likely disappear in its southernmost distribution limit, being the Sierra de las Nieves National Park population the most vulnerable in mainland Spain. For this reason, it is necessary to implement monitoring programmes for northern wheatear populations, with priority for mountain systems wherein they already occupy higher elevations, as well as further studies on other mountain species.

Regulating Big Tech expansionism? Sphere transgressions and the limits of Europe’s digital regulatory strategy

ABSTRACT The increasing power of Big Tech is a growing concern for regulators globally. The European Union has positioned itself as a leader in the stride to contain this expansionism; first with the GDPR and recently with a series of proposals including the DMA, the DSA, the AI Act, and others. In this paper we analyse if these instruments sufficiently address the risks raised by Big Tech expansionism. We argue that when this phenomenon is understood in terms of ‘sphere transgressions’ – i.e., conversions of advantages based on digital expertise into advantages in other spheres of society – Europe’s digital regulatory strategy falls short. In particular, seen through the lens of sphere transgressions, Big Tech expansionism raises three risks in addition to well-known privacy and data protection risks, which this regulatory strategy does not properly address. These are: non-equitable returns to the public sector; the reshaping of sectors in line with the interests of technology firms; and new dependencies on technology firms for the provision of basic goods. Our analysis shows that this mismatch may be inherent to Europe’s digital strategy, insofar as it focusses on data protection – while data is not always at stake in sphere transgressions; on political and civil rights – while socio-economic rights may be more at risk; and on fair markets – while the sectors being transgressed into by Big Tech, such as health and education, are not markets that require fairer competition, but societal spheres which need protection from market (and digital) logics.

Characterization of the bacterial microbiome of Swedish ticks through 16S rRNA amplicon sequencing of whole ticks and of individual tick organs

BackgroundThe composition of the microbial flora associated with ixodid ticks has been studied in several species, revealing the importance of geographical origin, developmental stage(s) and feeding status of the tick, as well as substantial differences between tissues and organs. Studying the microbiome in the correct context and scale is therefore necessary for understanding the interactions between tick-borne pathogens and other microorganisms as well as other aspects of tick biology.MethodsIn the present study the microbial flora of whole Ixodes ricinus, I. persulcatus and I. trianguliceps ticks were analyzed with 16S rRNA amplicon sequencing. Additionally, tick organs (midguts, Malpighian tubules, ovaries, salivary glands) from flat and engorged I. ricinus female ticks were examined with the same methodology.ResultsThe most abundant bacteria belonged to the group of Proteobacteria (Cand. Midichloria mitochondrii and Cand. Lariskella). 16S amplicon sequencing of dissected tick organs provided more information on the diversity of I. ricinus-associated microbial flora, especially when organs were collected from engorged ticks. Bacterial genera significantly associated with tick feeding status as well as genera associated with the presence of tick-borne pathogens were identified.ConclusionsThese results contribute to the knowledge of microbial flora associated with ixodid ticks in their northernmost distribution limit in Europe and opens new perspectives for other investigations on the function of these bacteria, including those using other approaches like in vitro cultivation and in vitro models.Graphical

Trace-level quantification of ethylene oxide and 2-chloroethanol in low-viscosity hydroxypropyl methylcellulose with solid phase microextraction and GC-MS

Ethylene oxide (EtO) is naturally present in numerous food products but recently EtO and its degradation product of 2-chloroethanol (2-CE) have been reported in amounts exceeding the maximum residue limit in Europe. The reports include hard capsules for dietary supplements made from low viscous hydroxypropyl methylcellulose (HPMC). The European council (EC) has proposed a generalized method for spices, seeds, and capsules utilizing QuEChERS, solid phase extraction (SPE), and GC-MS/MS to accommodate the need for analyte specificity, trace-level analysis, and higher throughput. HPMC has unique solvation properties and, without care, can potentially be transferred to the instrument. The current work presents the development of two methods specific for EtO and 2-CE in low viscous HPMC using solid phase microextraction (SPME) and GC-MS. Method optimization for solvation, SPME settings, and GC-MS settings are presented along with validation based on standard addition. Both methods present a high degree of specificity and limits of detection (EtO 6.7 µg/kg and 2-CE 12 µg/kg), comparable to those obtained with the EC method. Apart from sampling, the methods were fully automated and rely on low cost GC-MS instrumentation, widely available. Analyzed samples did not contain EtO or 2-CE, and method development was done with spiked samples. Contamination from plastic containers and analytical carry-over are shown as possible sources of EtO and 2-CE.

The Mongol “Other” and the Limits of Europe’s Christian Self-Perception

In a 1250 C.E. letter to Pope Innocent IV regarding a possible Mongol invasion, King Bela IV of Hungary vividly illustrates the self-perception of Europe as a Christian civilization through a conflation of Europe and Christendom. However, the limits of this civilizational self-perception are revealed through an analysis of an earlier series of letters between the chief of the Mongols Guyuk Khan and Pope Innocent IV.

Upper thermal threshold of Lepidurus arcticus (Branchiopoda, Notostraca) in lakes on the southern outreach of its distribution range

The Arctic tadpole shrimp Lepidurus arcticus has a circumpolar distribution and the Scandes (Fennoscandian Mountains) marks its southernmost limit in Europe. Within this area, 391 natural and 88 regulated lakes with L. arcticus have been identified, of which 87% are above the treeline. The lakes hosting L. arcticus decrease in altitude from south to north, which results from its temperature preferences. The majority of the locations are at a lower lake air temperature than 11°C which is equivalent to a water temperature near 14°C. This is assumed to be near the upper thermal threshold for L. arcticus. In lakes that exceed this average summer water temperature (1 July – 15 September), sustainable populations seem to be rare. In warmer lakes, life cycle mismatches are assumed to explain the absence of L. arcticus, most likely by affecting the embryo and juvenile stages. The distribution appears to be dichotomous, with one large northern area north of 65°N and one separated southern “island”. Only two locations of L. arcticus are known for the area between latitudes 62.88 and 64.39°N. In this part of the Scandes, the lakes are likely too warm to host L. arcticus as most of them are situated below 700 m a.s.l. This may also be the case in the northernmost region, north of 70°N, where only 11 populations are recorded. Most of the lakes in this area typically occurs below 400 m a.s.l. L. arcticus populations are sensitive to fish predation, and dense fish populations may be another stressor limiting its distribution. In contrast to water bodies in the High Arctic where L. arcticus only exists in shallow, fishless ponds, in the Scandes they co-exist with fish in 97% of the findings. Global warming has already modified the environment of the Scandes, and populations of L. arcticus are at threat in many of the small and shallow water bodies at low altitudes.

Climatic drivers of Sphagnum species distributions

Peat mosses (genus Sphagnum) dominate most Northern mires and show distinct distributional limits in Europe despite having efficient dispersal and few dispersal barriers. This pattern indicates that Sphagnum species distributions are strongly linked to climate. Sphagnum-dominated mires have been the largest terrestrial carbon sinks in Europe over the last few millennia. Understanding the climatic drivers of Sphagnum species distributions is important for predicting the future functionality of peatlands. We used MaxEnt, with biologically relevant climatic variables, to model and clarify the current distributions of 45 Sphagnum species in Europe. We used a dataset of 238 316 records from across Europe (30° to 90° N, -30° to 63° E; Sahara to the Arctic, Azores to Ural mountains). We used annual degree-days, annual water balance and their monthly standard deviations (i.e. seasonality) as climatic predictors over a range of spatial resolutions (from 10 to 200 km pixel size). With these climatic predictors, we produced reasonably accurate projections of the distribution of 45 species (overall AUC >0.8). Large pixels (100 and 200 km) resulted in loss of detail, but smaller pixels (10-50 km) performed well across fit measurements. Projected distributions at the 50 × 50 km resolution showed the largest resemblance to published distribution maps. Suitable climate for many Sphagnum species was associated with the northern, western and mountainous parts of Europe. We found that annual water balance was an important indicator of Sphagnum presence. Limits in relation to annual water balance were the same as reported by bioclimatic peatland models from North America. Most Sphagnum species were limited to annual degree-days between -5000 °C y-1 and 5000 °C y-1. Seasonality in both climate variables separated species, with degree-day seasonality having a stronger influence than water balance seasonality. High degree-day seasonality as a consequence of cold temperature sets a northern distribution limit to some species. The results suggest that the future of Sphagnum diversity in Europe is most strongly dependent on changes in water availability and in seasonal temperature variation.

Regeneration of submediterranean species Euonymus latifolius (L.) Mill. at its southernmost limit in Europe

Due to the ongoing effects of climate change in the Mediterranean (increasing temperature and decreasing rainfall), conditions for Submediterranean species are disappearing as their habitats are dwindling. We have focused on Euonymus latifolius (L.) Mill., a nemoral-Submediterranean species, at its southernmost populations of Europe. The aim was to evaluate the population structure and regeneration niche of the species at microhabitat scale. We selected five larger populations among the 13 existing ones, marking 25-30 individuals per population. We measured twice: height, width, vegetation cover, survival, soil moisture and temperature. As result, we provided data of the 13 existing populations, containing 93 adults and 350 juveniles.
 Moreover, we have obtained a very skew population structure with a low number of recruits for five selected populations, especially at smaller populations. Most E. latifolius juveniles were encountered under dense tree canopy (more than 80 % in cover) formed by a mixture of Submediterranean and Mediterranean species. Biovolume per population showed significant differences among the main populations CP and CV, presenting this last a higher recruitment, while recruitment was very low in general. For soil parameters, we found a critical role of canopy, which showed a positive effect on juvenile microhabitat (higher moisture and lower soil temperature).
 The results showed us the critical situation of the species, with very fragmented populations, low number of individuals, and scattered spatial patterns of individuals within the populations. Also, survival problems, a non-balance demographic structure, and regeneration problems were detected. Finally, we propose a sere of conservation measures, from monitoring to active measures (key tree species plantation, reintroduction, reinforcements), combined with threat control (herbivory, pests, and impact from outdoor activities). All combined may help to preserve this species at its southernmost populations.

Genetic diversity of alpine Dryas octopetala populations at their southern distribution limit in Europe

The arctic–alpine species Dryas octopetala has its southernmost European distribution in the northern part of Greece, where it forms isolated populations in three mountainous regions: Falakron, Tzena and Orvilos. This study aimed at estimating the intrapopulation genetic diversity and the overall genetic structure of these populations. A total of 20 randomly amplified polymorphic DNA (RAPD) markers were used. RAPD marker profiles revealed population differentiation, with Orvilos being the most differentiated population, indicating either genetic divergence or an independent origin. Intrapopulation genetic diversity indices were relatively low in all populations. Although isolation seem to have affected the genetic structure of D. octopetala populations at their southernmost European distribution limit, clonality and longevity of individuals might have contributed to maintaining their genetic diversity. The results emphasize the need for designing ex situ conservation management plans for conserving isolated alpine D. octopetala populations in the face of climate change.

Population biology and phenology of the colour polymorphic damselfly Ischnura elegans at its southern range limit in Cyprus

1. Geographically widespread species provide excellent opportunities to investigate how phenotypes change across large‐scale environmental gradients. Temperature is a fundamental environmental variable and an important determinant of insect fitness. However, field research is often geographically restricted, and typically concentrated in northern latitudes. Basic population biology and phenotypic clines in relation to temperature therefore remain poorly known across the entire geographic range, even in otherwise well‐studied taxa.2. We surveyed populations of the trimorphic damselfly Ischnura elegans in Cyprus, which is the southern range limit in Europe of this widespread insect species. Females of I. elegans occur in three discrete and heritable colour morphs, which vary in suites of phenotypic traits. One of these female morphs is a male‐mimic that avoids excessive male‐mating harassment by its male‐like appearance, and which is more cold‐tolerant than the two other morphs.3. In contrast to the situation in northern Europe, these male‐mimicking females are the minority morph in Cyprus, representing only about 5% of all females. Male mimics also have lower mating rates than alternative female morphs.4. Individuals in Cyprus are relatively small in comparison to the reported European range for body size, consistent with Bergman's rule.5. Finally, populations of I. elegans on the island have the longest flight period known in Europe, and there is only partial evidence for seasonality in flight activity.6. These results underscore the benefits of considering the entire range of environmental conditions encountered by insect species when conducting evolutionary ecology research.

First syntaxonomical contribution to the invasive Ailanthus altissima (Mill.) Swingle forest communities at its southern limit in Europe

Ailanthus altissima (tree of heaven), an invasive alien tree native to China, has become invasive all over the world and in Italy is present in all the administrative regions where it can form dense forest communities. Although there are several ecological studies on this species there is a lack of floristic-vegetational data for southern-Europe. The study presents the results of a floristic vegetational study on A. altissima forest communities of central Italy that aims to highlight the possible floristic-vegetational autonomy of these coenoses. The results have allowed the characterization of A. altissima coenoses at the ecological, biogeographic, syntaxonomic and landscape levels. These represent first A. altissima syntaxa described for the Italian peninsula and for southern-Europe. We propose two new sub-Mediterranean and Mediterranean associations comprised in the recently described alliance Lauro nobilis-Robinion pseudoaciae, in the Chelidonio-Robinietalia order and the Robinietea class: Asparago acutifolii-Ailanthetum altissimae: forest community with stratified structure and high canopy density on the warmer slopes of the hills in dry soil conditions and low anthropic disturbance and Aro italici-Ailanthetum altissimae: paucispecific forest communities with a monolayered structure typically found in agricultural, and peri-urban areas on pelitic, alluvial silty-sandy substrates, in conditions of edaphic humidity and high anthropogenic disturbance. The comparison with literature data highlights the autonomy of these associations of the sub-Mediterranean and Mediterranean alliance Lauro nobilis-Robinion pseudoacaciae alliance from the Balloto nigrae-Ailanthetum altissimae association of the Central and SE-European Balloto nigrae-Robinion pseudoacaciae alliance.

Secondary forest succession in Silver birch (Betula pendula Roth) and Scots pine (Pinus sylvestris L.) southern limits in Europe, in a site of Natura 2000 network – an ecogeographical approach

Aim of the study: To investigate the secondary forest succession in the study area and the pathways of its spread and the existing environmental, autecological factors and possible inter-specific competition relationships.Area of study: The study area is a Site of Natura 2000 network in northern Greece dominated by two pioneer forest species, Betula pendula and Pinus sylvestris. Study area is the southern limit of Silver birch in Europe and genotypes of these forests may be important due to the anticipated global increase of temperature and the forthcoming climate change.Materials and methods: The main forest types studied were: pure forests of B. pendula and P. sylvestris and mixed forests of these two main species. To study the expansion of forests in the area, a spatial analysis was performed based on geographical data. To detect forest changes, the rate thereof and their specific spatial distribution and preferences, a statistical analysis was performed.Main results: Approximately 60% of the studied area in 1945 was transformed from grasslands/barelands to forests. The composition of new forests was found to be different from the old ones. The rate of forest establishment in the first years was lower than in the latter years. All factors examined played an important role to the expansion of forest exept slope.Research highlights: Distance from the old stands played the most determining role to new forest structure and composition. Inter-specific competition results to the formation of pure stands, as indicated by the older stands.Keywords: secondary forest succession; Betula pendula; GIS; spatial analysis; forest species competition; forest species distribution.

Assessing the effect of recovery programs for salmon (Salmo salar Linnaeus, 1758) at its Southern limit in Europe: application of segmented regression models to long-term data from the Ulla River

The abundance of Atlantic salmon in Europe has declined throughout its native range. One of the main causes is low marine survival, which has been mainly attributed to overexploitation at sea, but global warming, decreased zooplankton abundance in the North Atlantic and local changes in freshwater conditions have been also blamed. It has been also pointed out that Southern populations experience the greatest decline, but information from these areas in Europe is scarce, and also in Spain there are few long-term data series related with the salmon recovery programs carried out. In this paper, we analyse a long-term data set (1992-2018) provided by a fish-trap located in the Ulla River (Galicia, NW Spain), at the southern limit of the salmon distribution range. Salmon restocking programs have been carried out in this river from 2000, and although this management technique is widely accepted, it is necessary to document the fate of those individuals to evaluate their success. Segmented regression models (or piecewise regression) are applied here for the first time to estimate the value of the explanatory variable (the so called break-point) which can indicate the potential success of the recovery program in this river. Data analysis suggest a gradual population increase to the early 1990s, then remained relatively stable until 2007 and increased thereafter due to an increase in the number of wild salmon entering the river. An increase in the frequency of appearance of 3SW salmon since 2009 was detected, both including previous spawners and individuals at its first spawning migration after three consecutive winters at sea. Data suggest an increase in number of wild salmon entering the river. Restoring river connectivity has also helped to enhance this population. We finally consider that the increase in the number of returning salmons in the Ulla River achieved over this period is due not only to the good management and conservation practices related to salmon stocking, but also to the connectivity restoration in the river and to a higher marine survival rate.

Care and cruelty in Chios: the “refugee crisis” and the limits of Europe

ABSTRACTFocusing on Chios, at the start of 2016, and my experience there as a volunteer, this paper aims to understand the forms of violence that unfolded in that location and considers what they mean for the social and political transformation of Europe. Violence takes many forms, but in this paper I focus on cruelty – specifically, modern, colonial and racial acts of excessive violence committed without regard for the victim. Secondly, the paper develops a feminist and postcolonial analysis of care. This analysis is concerned with acts of empathy, responsibility and relation that acted as correctives to cruelty. The paper shows how cruelty and care are intertwined and how their quotidian workings reveal wider patterns of violence and responsibility. However, rather than reiterate that care is ensnared in cruelty, this paper defends care’s autonomy, vitality and centrality to an alternative humanist ethics.

Is homo oeconomicus an extinct species, and does it matter for EUropean integration? Attitudes towards free trade and populism

The latest Nobel Prize winner in economics, Richard Thaler, was rewarded 'for his contributions to behavioural economics'. Thaler and Sustain claim that there are 'nudges', not pure rationality, that drive people decision-making processes. A 2017 CEPR report reveals that economic factors do matter with regards to trust in the political institutions of the EU but they do not play the main role. Therefore, it seems quite natural to ask: what is an explanatory power of economics in grasping the recent social behaviour dynamics, including the European integration processes and actual rise of radicalism and populism? Can economics contribute to a better understanding of those issues and can it come up with some practical solutions? To answer these questions I explore both theoretical backgrounds in economics and some empirical studies. I also refer to the results of my recent research on the Polish social perception of free trade agreements. I investigate how much the limits of EUrope are related to the limits of economics.

Response to ‘Migration, solidarity and the limits of Europe’ by Martina Tazzioli and William Walters

Response to ‘Migration, solidarity and the limits of Europe’ by Martina Tazzioli and William Walters

Migration, solidarity and the limits of Europe

In this paper we examine the increasing criminalisation by states and the EU of citizen networks that have mobilised across Europe for supporting migrants in transit. Through these transnational solidarity practices a sort of infrastructure of migrant support has been built. The paper focuses on ‘crimes of solidarity’ that have taken place in France and in Italy and argues that the criminalisation of individuals which build solidarity connections across borders paradoxically constitutes a radical challenge to Europe’s principles of citizens’ solidarity across borders. The infrastructure of migrant support enacts a form of Europeanisation of citizens’ practices that states and local authorities try instead to undermine. The paper moves on by focusing on the ambivalences of the expression ‘smuggling activities’, which is increasingly being used to name individuals who help migrants to cross or to stay without making any economic profit from that. The essay considers the frictions between local, national and European authorities in tolerating or criminalising citizens that act in solidarity with the migrants, bringing humanitarian help and building material channels for safe passages. The final part of the paper reads the moment of crimes of solidarity in terms of a genealogy of European borders. It argues that one consequence of the criminalisation of solidarity is that new hybrid forums concerning migration, citizenship and borders questions are emerging. These arise, for example, when citizens are prosecuted for acts of assistance. Their trials have potential to become public scenes and spaces of counter-politics where it is not only the citizen but Europe that is in the dock. While some have argued that criminalisation and humanitarianism closes down the politics of European borders, we argue that it may allow for unexpected political opportunities.