Northward Migration Research Articles

Mid-Miocene to Present Upper-Plate Deformation of the Southern Cascadia Forearc: Effects of the Superposition of Subduction and Transform Tectonics

The southern Cascadia forearc undergoes a three-stage tectonic evolution, each stage involving different combinations of tectonic drivers, that produce differences in the upper-plate deformation style. These drivers include subduction, the northward migration of the Mendocino triple junction and associated thickening and thinning related to the Mendocino Crustal Conveyor (MCC) effect, and the NNW translation of the Sierra Nevada-Great Valley (SNGV) block. We combine geodetic data, plate reconstructions, seismic tomography and topographic observations to determine how the southern Cascadia upper plate is deforming in response to the combined effects of subduction and NNW-directed (MCC- and SNGV-related) tectonic processes. The location of the terrane boundaries between the relatively weak Franciscan complex and the stronger Klamath Mountain province (KMP) and SNGV block has been a key control on the style of upper-plate deformation in the southern Cascadia forearc since the mid-Miocene. At ∼15 Ma, present-day southern Cascadia was in central Cascadia and deformation there was principally controlled by subduction processes. Since ∼5 Ma, this region of the Cascadia upper plate, where the KMP lies inboard of the Franciscan complex, has been deforming in response to both subduction and MCC- and SNGV-related effects. GPS data show that the KMP is currently moving to the NNW at ∼8–12 mm/yr with little internal deformation, largely in response to the northward push of the SNGV block at its southern boundary. In contrast, the Franciscan complex is accommodating high NNW-directed and NE-directed shortening strain produced by MCC-related shortening and subduction coupling respectively. This composite tectonic regime can explain the style of faulting within and west of the KMP. Associated with this Mendocino Crustal Conveyor crustal thickening, seismic tomography imagery shows a region of low velocity material that we interpret to represent crustal flow and injection of Franciscan crust into the KMP at intracrustal levels. We suggest that this MCC-related crustal flow and injection of material into the KMP is a relatively young feature (post ∼5 Ma) and is driving a rejuvenated period of rock uplift within the KMP. This scenario provides a potential explanation for steep channels and high relief, suggestive of rapid erosion rates within the interior of the KMP.

Within- and between-Year Variation in the Presence of Individually Marked Ruff Calidris pugnax at a Stopover Site during Northward Migration

Ruffs Calidris pugnax migrate from wintering areas in West-Africa and Europe to breeding grounds in northern Eurasia, using stopover sites along the way. At one such stopover site in southwest Friesland (53°N, The Netherlands), we studied variation in the timing of individual stopover based on 6474 Ruffs colour-ringed in 2004–2012. 43% of males and 22% of females were recorded in the study area in March–May the years following marking. Minimal stopover duration of returning individuals showed substantial within-year heterogeneity. We distinguished two classes: (1) ‘transient’ individuals were observed only on a single day in the study area within a season (51% of observed males and 79% of females), and (2) ‘staging’ individuals were observed on multiple days. We observed two seasonal peaks in the presence of transient Ruffs, typically coinciding with the peak of arrival and departure of staging birds. Males known to winter in Europe were more likely to be observed in the study area and arrived earlier than males of unknown winter origin (3.1 days and 3.7 days earlier for transient and staging males, respectively), but departure was unrelated to winter origin. Staging and transient females arrived later than males. Between-year repeatability of individual behaviour was low, and individuals did not significantly advance their arrival date over the course of years, in contrast with a pattern of shifting arrival dates at the population level. The observation that a large proportion of Ruffs visit southwest Friesland for only a short stop suggests that many individuals rely on other sites for moulting and refuelling during spring migration. Resightings of marked individuals elsewhere in western Europe indicated that these sites are largely located between 51° and 54°N. Thus, during spring migration, Ruffs marked in southwest Friesland displayed high between- and within-individual variation in minimal stopover duration.

Depositional timing and palaeoclimate interpretation of the Tamala Limestone aeolianites in Shark Bay, Western Australia

• AAR dating shows an aging of the Tamala Limestone aeolianites towards the east. • The Tamala Limestone aeolianites are landward-advancing (i.e., transverse) dunes that have migrated from west to east. • Dune accumulation occurred during dry/cold glacials of the Pleistocene period. • Dune activity in the region is strongly linked to a weak Leeuwin Current. • Dune accumulation occurred during a northward shift of both the Hadley and Ferrel cells. The carbonate units grouped under the name “Tamala Limestone” outcrop for a thousand kilometres along the coast of Western Australia. The extensive Zuytdorp Cliffs shaping the northern half of the coastline up to Shark Bay expose and offer an exceptional access to the stratigraphy of this formation. The regional survey of the Shark Bay region, which combines both stratigraphic and sedimentological analyses, reveals that the Tamala Limestone is a dry accumulating aeolian system composed of large transverse dunes migrating parallel to the prevailing winds. Accordingly, the amino acid-data show an aging of the units towards the east. Episodes of carbonate aeolian sedimentation correlate with the successive glacial intervals of the Pleistocene whilst paleosols are correlated with breaks in the sedimentation during interglacial intervals. Palaeoclimate reconstructions reveal that sea level and sea surface temperature of the Indo-Pacific Warm Pool were lower during glacial intervals. The weakened Leeuwin Current, which flows along the western coast of Australia and is the main source of precipitation, contributed to the aridification of the region. Consequently, and associated with a northward migration of the Hadley and Ferrel cells, periods of glaciation were drier. By contrast, paleosols developed through dissolution of the carbonate units during more humid interglacial intervals.

Evidence of long-distance coastal sea migration of Atlantic salmon, Salmo salar, smolts from northwest England (River Derwent)

BackgroundCombining data from multiple acoustic telemetry studies has revealed that west coast England Atlantic salmon (Salmo salar L.) smolts used a northward migration pathway through the Irish Sea to reach their feeding grounds. Hundred Atlantic salmon smolts were captured and tagged in May 2020 in the River Derwent, northwest England as part of an Environment Agency/Natural England funded project.ResultsThree tagged smolts were detected on marine acoustic receivers distributed across two separate arrays from different projects in the Irish Sea. One fish had migrated approximately 262 km in 10 days from the river mouth at Workington Harbour, Cumbria to the northernmost receiver array operated by the SeaMonitor project; this is the longest tracked marine migration of an Atlantic salmon smolt migrating from the United Kingdom. This migrating fish displayed behaviours which resulted in fast northward migration. The remaining two fish were detected on a receiver array operated by a third project: the Collaborative Oceanography and Monitoring for Protected Areas and Species (COMPASS).ConclusionThese detections further provide evidence that migration to reach marine feeding grounds of at least a proportion of salmon smolts from rivers draining into the Irish Sea is northerly, though without a southern marine array it is impossible to conclude that this is the only route. The pattern of these detections would not have been possible without the collaborative efforts of three distinct and separately funded projects to share data. Further work is required to fully understand migration trajectories in this species on the west coast of the British Isles.

Identification of annual routines and critical stopover sites of a breeding shorebird in the Yellow Sea, China

Pied Avocets (Recurvirostra avosetta) are common migratory shorebirds in the East Asian–Australasian Flyway. From 2019 to 2021, GPS/GSM transmitters were used to track 40 Pied Avocets nesting in northern Bohai Bay to identify annual routines and key stopover sites. On average, southward migration of Pied Avocets started on 23 October and arrived at wintering sites (mainly in the middle and lower reaches of the Yangtze River and coastal wetlands) in southern China on 22 November; northward migration started on 22 March with arrival at breeding sites on 7 April. Most avocets used the same breeding sites and wintering sites between years, with an average migration distance of 1124 ​km. There was no significant difference between sexes on the migration timing or distance in both northward and southward migration, except for the departure time from the wintering sites and winter distribution. The coastal wetland of Lianyungang in Jiangsu Province is a critical stopover site. Most individuals rely on Lianyungang during both northward and southward migration, indicating that species with short migration distances also heavily rely on a few stopover sites. However, Lianyungang lacks adequate protection and is facing many threats, including tidal flat loss. We strongly recommend that the coastal wetland of Lianyungang be designated as a protected area to effectively conserve the critical stopover site.

Northward migration, molting locations, and winter residency of California breeding pigeon guillemots Cepphus columba

Pigeon guillemots Cepphus columba are ubiquitous along the coasts of the eastern North Pacific, yet little is known about their winter migration patterns, habitat needs, and potential threats faced during the non-breeding period. We used 3 seasons of year-long light level data from tagged individuals to estimate the migration timing and winter residency of pigeon guillemots breeding on Southeast Farallon Island in California (USA). Light level data were combined with a movement model to estimate positions of tagged animals, revealing that individuals from this population undertook a coordinated coastal migration north in the fall, stopping at sites near Haida Gwaii in British Columbia (Canada), presumably during a flightless prebasic molt, before continuing north to stationary overwintering sites in coastal British Columbia and Southeast Alaska. Birds then made an uninterrupted migration south in the spring, returning to waters around Southeast Farallon in late March and early April. Wet/dry data indicated nocturnal resting on land during the breeding season and likely on the water throughout the non-breeding months. This is the first study to confirm the migratory patterns of pigeon guillemots from California, and highlights the importance of the waters of British Columbia and Southeast Alaska for the studied population and possibly other major populations of this species.

元江-李仙江流域亚洲象生境适宜性评价——基于荟萃分析和遥感大数据分析

PDF HTML阅读 XML下载 导出引用 引用提醒 元江-李仙江流域亚洲象生境适宜性评价——基于荟萃分析和遥感大数据分析 DOI: 10.5846/stxb202106241680 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 第二次青藏高原综合科学考察研究（2019QZKK0402）；国家自然科学基金项目（41971239，41461017） Habitat suitability evaluation of Asian elephants in the Yuanjiang-Lixianjiang River Basin based on meta-analysis and remote sensing big data Author: Affiliation: Fund Project: The second comprehensive scientific expedition to the Qinghai-Tibet Plateau(2019QZKK0402);The National Natural Science Foundation of China(41971239，41461017) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:生境适宜性评价是物种保护和生境管理与规划的基础。近几十年来，云南境内野生亚洲象数量剧增，外扩迁移事件频发，而新迁入区域生境适宜状况因物种出现点数据缺乏而难以评价，掣肘迁移亚洲象保护与风险防范应急。以亚洲象新近迁入的元江-李仙江流域为案例区，采用荟萃分析统计亚洲象生境评价因子，结合相关性分析和方差膨胀因子独立性检验，筛选出生境评价因子；基于开源遥感数据产品量化生境因子，综合主成分分析和层次分析计算生境评价因子权重，采用生境适宜性指数（Habitat Suitability Index，HSI）模型评价元江-李仙江流域亚洲象生境适宜性，并分析其景观格局。结果表明：（1）元江-李仙江流域亚洲象生境适宜性空间格局主要表现为由下游至上游呈递减趋势，最适生境主要分布于流域下游段，而流域上游段适宜生境少；（2）元江流域生境适宜性低于李仙江流域，且其生境斑块连接度更低、破碎化更严重；（3）2021年"北移象群"北迁沿程生境适宜性由西南向东北呈下降趋势。基于亚洲象生境适宜性评价结果，科学引导野生亚洲象迁入适宜生境区，以规避人象冲突，保障外迁亚洲象群及其活动区居民生命财产安全，服务于区域生物多样性保护与乡村振兴。 Abstract:Habitat suitability evaluation is a basis for species conservation, habitat management and planning. Over the past decades, the number of wild Asian elephants in Yunnan Province of China has increased sharply, and elephants' emigration from their original habitats frequently occurred. However, habitat quality in the newly inhabited areas is often poorly known due to lack of records in presence of Asian elephants, which hinders Asian elephant protection and risk prevention. The rapid development of remote sensing big data mapping technology provides new data sources for habitat suitability evaluation studies, and offers the possibility of identifying suitable habitats for species on a large regional scale more accurately and finely. In this study, a remote sensing big data-driven habitat suitability evaluation system for Asian elephants is constructed. We selected the Yuanjiang-Lixianjiang River Basin newly immigrated by Asian elephants as a case area, used meta-analysis to search for environmental factors related to Asian elephants habitat evaluation, and screened out habitat suitability evaluation factors by combining correlation analysis with variance inflation factor test. Subsequently, all habitat suitability evaluation factors were quantified based on open-source remote sensing data products and their weights were calculated using principal component analysis and analytic hierarchy process. Finally, we used a Habitat Suitability Index (HSI) model to determine the habitat suitability of Asian elephants in the study area and analyzed landscape patterns of habitats of Asian elephants. The results show that (1) the habitat suitability of Asian elephants in the Yuanjiang-Lixian River Basin decreased gradually upstream. The optimal habitat mainly occurred in the downstream basin, with a small distribution in the midstream basin and almost no distribution in the upstream basin. (2) The Yuanjiang River Basin was less suitable for Asian elephants than the Lixian River Basin because it had less connected and more fragmented habitat patches, which cannot meet the minimum home range requirements of Asian elephant populations and make it difficult to sustain a long-term survival of the "northward migration elephant herd". (3) The habitat suitability decreased along the northward migration route of elephant herd called "northward migration elephant herd" roaming in 2021 with the decreased distribution of natural broad-leaved forests along the way. The findings provide a basis for scientifically guiding the elephant herd into suitable habitats to avoid the conflicts between the human and wild elephant and thereby to ensure the safety of the elephant herd and the affected residents, which will serve for the regional biodiversity conservation and rural revitalization. 参考文献 相似文献 引证文献

Arriving depleted after crossing of the Mediterranean: obligatory stopover patterns underline the importance of Mediterranean islands for migrating birds

AbstractHundreds of millions of birds reach the Mediterranean islands or Mediterranean coast of Europe every spring after having crossed the Sahara Desert and the Mediterranean Sea. Using data from three small insular stopover sites, we calculated body mass without fuel for 18 trans-Saharan passerine migrants. We subsequently used arrival fuel loads coupled with potential flight range estimates to assess the percentage of birds that are forced to perform an obligatory stopover after crossing the Mediterranean Sea due to fuel depletion. Average arrival fuel loads were among the lowest ever recorded in the Mediterranean region and minimum body mass values recorded for several species were lower than any other individual value reported. The percentage of birds that needed to replenish their energy stores before resuming their northward migration journey varied from 0% to 50% depending on the species and locality studied. Based on conservative estimates at least 180 million birds of our study species are expected to migrate through Greece, 14% of which would not be able to resume their migration without refueling. The significance of small islands and coastal sites in the Mediterranean as obligatory refuelling sites is discussed and their conservation value for migratory birds is highlighted under the perspective of climate change.

Sexual dimorphism and sex-differential migration of Little Buntings (Emberiza pusilla) at an East Asian stopover site

Sex differences in morphology provide key information for understanding a species' morphological adaptations in relation to the evolution of sexual selection. In migratory birds, morphological traits have adapted to long-distance travel, and sexual dimorphism is typically related to sex-differential migration phenology. Little Buntings (Emberiza pusilla) have one of the longest migrations and are the least dichromatic species among the Emberiza buntings. In this study, we measured sexual size dimorphism and sexual dichromatism of Little Buntings in relation to the spring arrival dates at a stopover site in Korea. Wing length was the most important predictor for identifying sex; the wings of males were longer than those of females. Males also had a significantly stronger chestnut color of the head feathers than females, but this color difference was more prominent in the spring than in the fall. Males arrived earlier than females by four days. Arrival dates correlated with both size and color, but unlike other bunting species previously studied in the same area, there was no clear sex-differential trend in the relationship between arrival date and morphological characteristics. Seasonal differences in the degree of sexual dichromatism suggest that chestnut plumage coloration can be used as a social or sexual signal of males in the breeding season. The correlation of size and color to early arrival regardless of sex may indicate that a preference for assortative mating exists or that a sex-differential migration strategy is not clearly defined in the early stages of northward migration. Our findings on the sexual dimorphism of Little Buntings provide insight into the evolution of the sex-differential migration of buntings in the East Asian Flyway.

Zircon U–Pb ages of the Higo plutonic complex: Implication for migration of Cretaceous igneous activity in Kyushu, southwest Japan

AbstractZircon U–Pb weighted mean ages of seven samples from the Higo plutonic complex (HPC) in Kyushu were determined as follows; Shiraishino granodiorite: 109.3 ± 0.9 Ma and 109.0 ± 1.1 Ma; Kugushima granodiorite: 109.1 ± 1.1 Ma; Miyanohara tonalite: 107.7 ± 1.3 Ma and 108.3 ± 0.9 Ma; Manzaka tonalite: 108.0 ± 0.9 Ma; Joyama tonalite: 112.7 ± 1.2 Ma. The plutonism of batholithic granitoids in the HPC occurred in 109–108 Ma, and granitic intrusions occurred in 113 Ma. The previously reported zircon U–Pb ages range from 107 to 98 Ma in northern Kyushu and concentrate around about 106 Ma in the Chikuhi area in the northern part of central Kyushu. The previously published age data and newly obtained data in this study demonstrate that Cretaceous igneous activity in Kyushu migrated northward from 114 to 98 Ma, accompanied by widespread igneous activity throughout central and northern Kyushu at 106–105 Ma. The HPC situated in the southernmost part of central Kyushu was the origin of this northward migration.

Widespread recent ecosystem state shifts in high-latitude peatlands of northeastern Canada and implications for carbon sequestration.

Northern peatlands are a major component of the global carbon (C) cycle. Widespread climate-driven ecohydrological changes in these ecosystems can have major consequences on their C sequestration function. Here, we synthesize plant macrofossil data from 33surficial peat cores from different ecoclimatic regions, with high-resolution chronologies. The main objectives were to document recent ecosystem state shifts and explore their impact on C sequestration in high-latitude undisturbed peatlands of northeastern Canada. Our synthesis shows widespread recent ecosystem shifts in peatlands, such as transitions from oligotrophic fens to bogs and Sphagnum expansion, coinciding with climate warming which has also influenced C accumulation during the last ~100years. The rapid shifts towards drier bog communities and an expansion of Sphagnum sect. Acutifolia after 1980 CE were most pronounced in the northern subarctic sites and are concurrent with summer warming in northeastern Canada. These results provide further evidence of a northward migration of Sphagnum-dominated peatlands in North America in response to climate change. The results also highlight differences in the timing of ecosystem shifts among peatlands and regions, reflecting internal peatland dynamics and varying responses of vegetation communities. Our study suggests that the recent rapid climate-driven shifts from oligotrophic fen to drier bog communities have promoted plant productivity and thus peat C accumulation. We highlight the importance of considering recent ecohydrological trajectories when modelling the potential contribution of peatlands to climate change. Our study suggests that, contrary to expectations, peat C sequestration could be promoted in high-latitude non-permafrost peatlands where wet sedge fens may transition to drier Sphagnum bog communities due to warmer and longer growing seasons.

Genetic diversity, gene flow and hybridization in fan-shaped sponges (Phakellia spp.) in the North-East Atlantic deep sea

Deep-sea North Atlantic sponge grounds are crucial components of the marine fauna providing a key role in ecosystem functioning. To properly develop effective conservation and management plans, it is crucial to understand the genetic diversity, molecular connectivity patterns and turnover at the population level of the species involved. Here we present the study of two congeneric sponges, Phakellia robusta and Phakellia hirondellei, using multiple sources of evidence. Our phylogenetic study using a fragment of COI placed these two species as sister. Haplotype network analysis using COI revealed no genetic structure for P. hirondellei in samples from the Cantabrian Sea (<100 km). Contrastingly, P. robusta showed a clear genetic structure separating deep-water samples from the Cantabrian Sea and the Hatton-Rockall Basin, from samples from shallower waters from Kerry Head Reefs, NW of Orkney, and Norway. ddRADseq-derived SNPs for P. robusta also segregated samples by bathymetry rather than by geographical distances, and detected a predominant northwards migration for shallow-water specimens connecting sites separated ca. 2,000 km, probably thanks to prevalent oceanographic currents. Importantly, our analysis using SNPs combining the datasets of the two species revealed the presence of potential hybrids, which was corroborated by morphological (spicule) and microbial (16S amplicon sequencing) analyses. Our data suggest that hybridization between these two species occurred at least two times in the past. We discuss the importance of using next-generation techniques to unveil hybridization and the implications of our results for conservation.

Critical Discourse Analysis of Chinese English News Reports from the Perspective of Ecolinguistics

This study makes a Critical Discourse Analysis of the ecological and non-ecological features of Chinese English news reports and holds that news reports ultimately serves the interest groups it represents and cannot get rid of its ideological influence. To achieve this, with Fairclough’s three-dimensional model as the theoretical framework and from the perspective of ecolinguistics, this study, based on 29 English news reports on the northward migration of Asian elephants from China Daily and by building up a small corpus, combining qualitative and quantitative research methods, aims to analyze the selected corpus with the help of AntConc 3.5.9 (windows) 2020. Finally, through the analysis of text analysis, discourse interpretation, and social interpretation, it is found that Chinese and English news reports have ecological and non-ecological features. At the same time, English news reports in China also try to express and build a harmonious relationship between man and nature. It reflects that China follows the ecological order concept of “harmonious co-existence between man and nature” and the ecological basis of “man and nature are the community of life”.

Effects of climate change in the seas of China: Predicted changes in the distribution of fish species and diversity

Long-term habitat shifts in marine fishes under climate change have been discussed over the last few decades. However, there is still a limited understanding of how fish distribution and biodiversity patterns will change in the offshore areas of China over time. In the present study, the potential distributions of 21 important marine fishes under current conditions and two climate change scenarios up to the 2050 s were projected using the maximum entropy (MaxEnt) model. The predicted habitat shifts were further used to observe how future environmental changes would affect communities. By the 2050 s, nine out of 21 fish species may have reduced habitats, which were considered as potential loser species in adapting to climate change, while the other 12 fish species were considered as winner species. The habitats of 20 species were predicted to move northward, with a mean habitat centroid shifting distance from 110 to 206.5 km. A novel discovery is that the Yangtze River Estuary is probably a geographical barrier for the northward migration of some species. An asymmetry in the habitat range shift was observed within the study region, wherein the leading edge moved 1° faster than the trailing edge. The Beibu Gulf, Pearl River Estuary, Southwest Taiwan Strait, and Yangtze River Estuary were identified as fish refuges, indicating that large river estuaries and upwelling systems may have positive effects on reducing the vulnerability of biological communities to climate change. At the community level, species richness would be reduced at lower latitudes, while it would be increased at higher latitudes, and species turnover was the main component of temporal beta diversity. Our study provides an informative outlook on the impact of climate change on the distribution and biodiversity of marine fish species in China, supporting the adaptive conservation and management of fish habitats.

Age-dependent timing and routes demonstrate developmental plasticity in a long-distance migratory bird.

Longitudinal tracking studies have revealed consistent differences in the migration patterns of individuals from the same populations. The sources or processes causing this individual variation are largely unresolved. As a result, it is mostly unknown how much, how fast and when animals can adjust their migrations to changing environments.We studied the ontogeny of migration in a long‐distance migratory shorebird, the black‐tailed godwit Limosa limosa limosa, a species known to exhibit marked individuality in the migratory routines of adults. By observing how and when these individual differences arise, we aimed to elucidate whether individual differences in migratory behaviour are inherited or emerge as a result of developmental plasticity.We simultaneously tracked juvenile and adult godwits from the same breeding area on their south‐ and northward migrations. To determine how and when individual differences begin to arise, we related juvenile migration routes, timing and mortality rates to hatch date and hatch year. Then, we compared adult and juvenile migration patterns to identify potential age‐dependent differences.In juveniles, the timing of their first southward departure was related to hatch date. However, their subsequent migration routes, orientation, destination, migratory duration and likelihood of mortality were unrelated to the year or timing of migration, or their sex. Juveniles left the Netherlands after all tracked adults. They then flew non‐stop to West Africa more often and incurred higher mortality rates than adults. Some juveniles also took routes and visited stopover sites far outside the well‐documented adult migratory corridor. Such juveniles, however, were not more likely to die.We found that juveniles exhibited different migratory patterns than adults, but no evidence that these behaviours are under natural selection. We thus eliminate the possibility that the individual differences observed among adult godwits are present at hatch or during their first migration. This adds to the mounting evidence that animals possess the developmental plasticity to change their migration later in life in response to environmental conditions as those conditions are experienced.

Limited Range-Filling Among Endemic Forest Herbs of Eastern North America and Its Implications for Conservation With Climate Change

Biodiversity hotspots host a high diversity of narrowly distributed endemic species, which are increasingly threatened by climate change. In eastern North America, the highest concentration of plant diversity and endemism occurs in the Southern Appalachian Mountains (SAM). It has been hypothesized that this region served as a refugium during Pleistocene glacial cycles and that postglacial migration northward was dispersal limited. We tested this hypothesis using species distribution models for eight forest herb species. We also quantified the extent to which the geography of suitable habitat shifted away from the current range with climate change. We developed species distribution models for four forest herb species endemic to the SAM and four that co-occur in the same SAM habitats but have broader ranges. For widespread species, we built models using (1) all occurrences and (2) only those that overlap the SAM hotspot in order to evaluate the extent of Hutchinsonian shortfalls and the potential for models to predict suitable habitat beyond the SAM. We evaluated the extent to which predicted climatically suitable areas are projected to shift away from their current ranges under future climate change. We detected unoccupied but suitable habitat in regions up to 1,100 km north of the endemic species’ ranges. Endemic ranges are disjunct from suitable northern areas due to a ∼100–150 km gap of unsuitable habitat. Under future climate change, models predicted severe reductions in suitable habitat within current endemic ranges. For non-endemic species, we found similar overall patterns and gap of unsuitability in the same geographic location. Our results suggest a history of dispersal limitation following the last glacial maximum along with an environmental barrier to northward migration. Conservation of endemic species would likely require intervention and assisted migration to suitable habitat in northern New England and Canada.

Épidémiologie de l’allergie aux venins d’hyménoptères

The prevalence of anaphylactic reactions to hymenoptera stings is estimated to be between 0.3 and 7.5%. Although allergists are mainly interested in generalized reactions, the development of knowledge about widespread local reactions may change their practice. Risk factors such as age, the existence of underlying pathologies, particularly cardiovascular, mastocytosis, and the severity of the previous reaction are well documented. On the other hand, the traditionally accepted aggravating role of beta-blockers and ACE inhibitors is questioned. Changes in climate and world trade influence the distribution of insects on the planet, and explain the northward migration of the polistes wasp, and the appearance in our regions of the “Asian hornet”. The new classification of diseases (ICD 11) should allow us to better understand the reactions to these insects.

Using migrating growth strata to confirm a ∼230-km-long detachment thrust in the southern Tarim Basin

The amount of fault slip and timing of fault activation are two fundamental elements of quantitatively structural analysis. Currently, these two parameters are mainly determined by the geometry of fault-related folds and the growth strata over the fault ramp. In this study, we propose a new type of growth strata that directly constrain both the amount of fault slip and the timing of fault activity at the fault flat based on interpretations of seismic reflection profiles and related numerical modeling of the Manan Structure along the southern Tarim Basin. The seismic sections show a rootless synform beyond the north limb of the Manan Anticline with the hinge dipping toward north. Numerical modeling suggests that this synform is a result of northward migration of the growth strata along with the slip of the underlying detachment thrust with a bulge at the fault surface. We define this type of growth strata ‘migrating growth strata (MGS)’. The dipping direction of the hinge of the synform marks the slip direction, the projecting distance of the hinge on the fault surface measures the slip amount, and the timing of the MGS represent the timing of the activity of the underlying detachment thrust. Analyses of the Manan MGS along the southern Tarim Basin suggest ∼13–22 km of northward fault slip passed by the Manan Structure along the basal Cenozoic detachment and was finally absorbed by the Mazatagh Belt, which confirms a ∼230-km-long detachment thrust along the southern Tarim Basin and provide key evidence to establish a kinematic linkage between the Hotan and Mazatagh Belts. Two-segment style of the hinge of the synform indicates that the Manan Structure has undergone two-stage evolution related to the lower Cambrian and the basal Cenozoic detachments, respectively. These results imply that detachments in difference depths and their sequential activities are key in transmitting strain from the Tibetan Plateau into the Eurasian continental interiors.

Differential population trends align with migratory connectivity in an endangered shorebird

AbstractMigratory connectivity describes the extent to which migratory species' populations are connected throughout the annual cycle. While recognized as critical for understanding the population dynamics of migratory species and conserving them, empirical evidence of links between migratory connectivity and population dynamics are uncommon. We analyzed associations between spatiotemporal connectivity and differential population trends in a declining and endangered migratory shorebird, the far eastern curlew (Numenius madagascariensis), with multiyear tracking data from across the Australian nonbreeding grounds. We found evidence of temporal and spatial segregation during migration and breeding: curlew from southeast Australia initiated northward migration earlier, arrived at breeding sites earlier, and bred at lower latitudes than curlew from northwest Australia. Analysis of land modification intensity revealed that populations from southeast Australia face greater human impacts compared to those from northwest Australia at both the breeding and nonbreeding grounds, a pattern that aligns with steeper population declines in southeast Australia. This alignment between migratory connectivity, human impacts, and differential population change highlights the importance of a full annual cycle approach to conservation that includes mitigating threats on the breeding grounds and better protecting nonbreeding habitats in Australia where far eastern curlew spend over half of each year.

Widespread wildfire across the Pliocene Canadian Arctic Archipelago

Arctic warming is expected to accelerate northward migration of the boreal zone, altering the boreal wildfire regime, with changes in fire frequency, intensity, size, and fire season length. The closest analogue to these future high latitude climate conditions occurred during the Pliocene Epoch (2.58–5.33 Ma). Palaeoenvironmental reconstructions at four Pliocene-aged sites across the Canadian Arctic Archipelago reveal that boreal forest occurred at the southern-most site on Banks Island (74.30°N), while open forest or tundra-forest ecosystems existed further north, characterized by species tolerant of low to moderate fire intensity. The climate that supported these ecosystems was much warmer and wetter than the current climate of the Canadian Arctic Archipelago. Charcoal was discovered in samples across all sites, suggesting that wildfire was ubiquitous within these ecosystems and climate regimes. The reflectance of the charcoal is consistent with crowning fire or a mixed fire regime on Banks Island and a surface fire regime on Meighen and Ellesmere islands. Boreal forest in southern Ontario, Canada, and open taiga are potential analogues for southern and northern Pliocene Arctic ecosystems, respectively.