Northern North America Research Articles

Boreolimnus, a new leafhopper genus from northern North America, with a review of Cribrus Oman (Hemiptera, Cicadellidae, Deltocephalinae)

Boreolimnus, a new leafhopper genus from northern North America, with a review of Cribrus Oman (Hemiptera, Cicadellidae, Deltocephalinae)

Do tobacco regulatory and economic factors influence smoking cessation outcomes? A post-hoc analysis of the multinational EAGLES randomised controlled trial

IntroductionWe previously reported global regional differences in smoking cessation outcomes, with smokers of US origin having lower quit rates than smokers from some other countries. This post-hoc analysis examined global...

A genome assembly for the Chryxus Arctic (Oeneis chryxus), the highest butterfly in North America.

We describe a highly contiguous and complete diploid genome assembly for the Chryxus Arctic, Oeneis chryxus (E. Doubleday, [1849]), a butterfly species complex spanning much of northern and western North America. One subspecies, the Ivallda Arctic (O. c. ivallda), is endemic to California's Sierra Nevada and of particular biogeographic interest and conservation concern. Extreme alpine habitats occupied by this subspecies include the summit of Mt. Whitney, California, representing the highest elevation butterfly population in North America. The assembly presented here consists of two haplotypes, 738.92 and 770.85Mb in length, with contig N50 values of 10.49 and 10.13Mb, scaffold N50 values of 25.35 and 25.69Mb, scaffold L50 values of 13 and 14, and BUSCO completeness scores of 96.5 and 98.3%, respectively. More than 97% of the assembly is organized into 29 scaffolds, which likely represent whole chromosomes. This assembly is the first major genomic resource for Oeneis, providing a foundational reference for future genomic studies on the taxonomy, evolutionary history, and conservation of the genus. As part of the California Conservation Genomics Project, we will use this assembly in conjunction with short-read resequencing to resolve patterns of evolutionary differentiation, adaptive genomic variation, and gene flow among remaining O. c. ivallda populations. These data can and will be used to inform the subspecies' conservation as warming climatic conditions continue to lead to the loss and fragmentation of alpine habitats. We also provide genome assemblies for the O. chryxus mitochondrion and a Wolbachia endosymbiont.

When Disease Came to this Country: Epidemics and Colonialism in Northern North America. Liza Piper

<i>When Disease Came to this Country: Epidemics and Colonialism in Northern North America</i>. Liza Piper

Non-Western Scholars, Bourgeois Virtues, and the International Scientific Community in the Age of Empire, 1870–1920

AbstractHistorians have long argued that science was fashioned as a bourgeois, Western cultural practice by the late nineteenth century, in ways that allowed its practitioners to exclude or distance themselves – through a rhetoric of endeavour, utilitarianism, and progress – from the more useless, ‘frivolous’ learning of aristocrats, women, or, indeed, native ‘informants’ in the colonies. This article examines the case of scholars from outside northern Europe and North America – Japanese literati, creole intellectuals, and Lebanese scholars – who managed to participate in the period’s Western scientific networks as peers. It holds that these men were able to establish epistemic credibility not because their lower rung in a political and racial hierarchy was ever irrelevant, but because their status as upper-middle-class professionals and their bourgeois habitus – their ‘civility’, and ‘manners’ – in some measure made up for it. The article reveals, rather than forthright ‘exclusion’ and ‘silencing’ of non-Europeans, complex epistemic hierarchies and geographies of knowledge. It exposes the mechanisms of epistemic inclusion and its limits in the period: the functioning of an academic community that was – in many, rather significant ways – also a social world.

Confusing boundaries of the Labrador Tea species: dispersal history explains the lack of clear species structure.

The Labrador Teas (genus Rhododendron, subsection Ledum) are a complex of species widely distributed in the Northern Hemisphere. They occupy cold-resistant plant communities from highlands to forest understory and wetland habitats almost circumboreally and they are especially abundant in Northeast Asia (NE Asia) and northern North America (NN Am), still there are no clear species boundaries in this group. The genetic structure of species of the subsect. Ledum from Eurasia and North America as well as the dispersal history of the group require clarification. Phylogeny and biogeography of the subsect. Ledum of the genus Rhododendron were assessed using phylogenetic trees constructed based on the analysis of variation in chloroplast petB-petD, trnV-ndhC, trnH-psbA, K2R-K707, atpB oligo2 - rbcL oligo5 and nuclear (ITS1) markers of four Eurasian and one American species (65 populations, 408 individuals). The data were evaluated with Maximum Parsimony and Bayesian analysis. Molecular dating and ancestral areas reconstruction were obtained. Dense sampling revealed widespread presence of shared haplotypes and ribotypes among Ledum populations and species. Two American, three Eurasian and one mixed lineage diversified during the Neogene climate cooling and then rapidly dispersed during the Pleistocene. The ability to accumulate high genetic diversity and to preserve it across distribution ranges and generations prevented Ledum from lineage sorting. As a result, a species complex with a reserve of genetic variability appeared. Although no clear phylogenetic inference can be obtained at present, the plastid genealogy is consisted with the nuclear genealogy and demonstrates the processes involved in speciation in the Ledum species complex.

Assessing global drought conditions under climate change: A comparison of stationary and non-stationary approaches and identification of hotspot regions

Droughts pose significant threats to both human society and the surrounding environment. Because of the anticipated intensification of drought conditions owing to climate change, assessing their impacts using dynamic and non-stationary methodologies is considerably required. This study employed temperature and precipitation data derived from a comprehensive set of 15 global climate models (GCMs) under two shared socioeconomic pathways (SSP2-4.5 and SSP5-8.5) within the framework of the Coupled Model Intercomparison Project Phase 6 (CMIP6) dataset to address crucial inquiries related to drought. Specifically, we explored the transformations that drought conditions may undergo with increasing temperature and precipitation levels. The study identified geographical areas likely to become hotspots of global warming and compared drought indices that incorporate non-stationarity with those that do not in assessing the evolution of global drought conditions. The findings revealed that indices using stationary approaches with fixed distribution parameters underestimate or overestimate future drought conditions because they overlook trends such as decreasing precipitation and increasing temperatures in drought variables. This results in an average misestimation of approximately 10 %–20 % in duration and severity in the far future in the sub-regions. Specifically, underestimations were detected in the high latitudes of the Northern Hemisphere (Alaska and Northern Asia), northwestern China, India, and northern and eastern Africa. Conversely, the stationary drought index exhibited maximum overestimations in the Amazon, Western Australia, the Mediterranean region, and South Africa regions for future drought projections. Combining the results of the multi-drought characterization, including frequency, duration, severity, and spatial extent, we identified Northern North America, the Amazon region, the Mediterranean region, south-central Africa, and southeastern Asia as hotspot regions for drought responses to global warming. In future drought warnings, particular attention should be directed toward regions where drought is underestimated.

Potential impact of climate change on Nearctic leafhopper distribution and richness in North America

Climate change significantly contributes to shifts in the geographical range of pests and diseases. Leafhoppers (Hemiptera: Cicadellidae), known vectors of phytoplasmas pathogens, are linked to the transmission of more than 600 diseases affecting a thousand plant species worldwide. Despite this, the potential effects of climate change on leafhopper vectors of phytoplasmas remain a critical knowledge gap. To address this gap, our study investigated the potential impact of climate change on 14 species of Nearctic leafhoppers previously associated with phytoplasma-related diseases. Using the MaxEnt species distribution algorithm and other ecological niche modeling techniques, we assessed (i) the expected species richness under current climate conditions and four future scenarios and (ii) the environmental niche similarity among these species across these scenarios. Our projections suggest that the eastern region of North America holds the potential for the highest species richness, a trend expected to persist across all future scenarios, gradually expanding eastward. Notably, our findings indicate the increasing suitability of northern Canada for more species. Network analysis further revealed a remarkable similarity in environmental niches among most leafhopper species. Moreover, across the four future scenarios, there is a tendency for an increase in this similarity. Altogether, our study underscores the potential persistent presence of Nearctic leafhoppers in their current habitats while pointing to a shift toward northern North America in future scenarios. These findings have significant implications for sustainable pest management practices, prompting a necessary discussion on strategies to mitigate climate change and pest migration’s impact on agricultural systems.

Water retention curves of sandy soils obtained from direct measurements, particle size distribution, and infiltration experiments

AbstractAccurate information about soil water retention curves (SWRCs) of sands is essential for evaluating groundwater recharge and vulnerability to contamination in many shallow sandy aquifers which are widespread on post glacial areas in Northern Europe and North America. Pedotransfer functions (PTFs) allow to estimate SWRC from basic physical characteristics of soils, such as textural composition. However, in the case of clean sands which are dominated by a single textural fraction, PTFs should be based on more detailed information given by the particle size distribution. In this study we evaluated three parametric PTFs, which estimate parameters of the van Genuchten SWRC based on empirical correlations to the parameters of soil particle size distribution, and five semi‐physical PTFs, which derive the pore size distribution from particle size distribution. PTFs were compared to SWRCs fitted to the results of drainage experiments on sandy soil samples from six locations in Gdańsk region (northern Poland). Although in all samples the content of silt and clay fractions was low (&lt;3.5%), the differences in actual content of fines strongly influenced the shape of SWRC. In contrast, the amount of gravel fraction (varying from 1% to 35%) did not have significant effect on SWRC. Semi‐physical PTFs were found to be more accurate than parametric PTFs. The best overall performance was shown by the semi‐physical Chang and Cheng PTF. Among the parametric PTFs the best accuracy was obtained with the Schaap and Bouten method. However, all considered functions showed limited accuracy in higher suction range. Additionally, infiltration experiments were performed on four sites. SWRCs were obtained from ring infiltrometer tests using the Beerkan estimation of soil transfer parameters (BEST) method and from the tension infiltrometer (TI) tests using numerical solution of the inverse problem based on the Richards equation. In almost all cases the wetting SWRCs were characterized by higher values of the pressure scaling parameter α compared to SWRCs measured in drainage experiments, which is consistent with the well‐known phenomenon of hysteresis in soils. However, the BEST method resulted in significantly higher α and hydraulic conductivity Ks than TI, probably due to activation of the largest soil pores during ponded infiltration.

“Especially in This Free Country”: Webs of Empire, Slavery, and the Fur Trade

Spanning the years from late 1600s and into the early 1800s “‘Especially in This Free Country:’ Webs of Empire, Slavery and the Fur Trade” challenges a historiography that positions what has come to be known as the Canadian fur trade as exceptional in its relationships between colonizers and Indigenous peoples, where interactions between Indigenous producers and non-Indigenous traders are presented as largely cooperative and peaceful and as rooted in relationships that operated in the absence of coerced or unfree labour. In fact, the fur trade, connected as it was through webs of family/business relationships to the rest of the colonial world was not exceptional. Across northern North America the fur trade world experienced the same sorts of violence, including chattel slavery, as the rest of the empires with which these webs connected. Far from absent, colonial violence was a part of the Canadian fur trade just as it was a part of empire. Located in the pre-history of Canada, this thesis responds to Harvey Amani Whitfield’s observation that, although there have been some excellent studies of slavery in Canada recently, “slavery has not become part of the Canadian national narrative” 1 by arguing that chattel slavery in the fur trade in what would become Canada was linked to the empires it was a part of, pervasive, integrated into all aspects of the fur trade, and occurred across the northern North American continent.

Tree species distributions in the United States and Canada under climate from 20,000 years ago to year 2100

Current locations of species may not be suited to future climate, resulting in ranges that shift to higher latitudes, with potential for range expansion or contraction in extent. To identify potential shifts in distributions of 119 tree species centered in the United States and Canada, I modeled species occurrences under current climate and then predicted to past (20, 10, and 6 thousand years ago) and future climates (six projections during 2071–2100 for North American warming of 4.3 °C to 8.8 °C), with a singular focus on the climate space of tree species, or bioclimatic envelope models. Mean accuracies of withheld samples for models, based on climate of 1900 to 1990, were 0.97, with an average of 6.2 variables per model; annual temperature and temperature of the warmest quarter generally were the most important variables. Based on model predictions under past and future climate, centers of species distributions shifted an average of 565 km latitudinally since climate 20,000 years ago and 440 km to 1065 km shifts were expected in response to end-of-century climates. Overall, 64 tree species may gain more area than lose area that matches current climate space under future climate, whereas 36 species may lose potential climate space, with relative stability for 19 species. Canada and the mountainous western U.S., and National Forests in the mountainous western U.S., were likely to gain climate space appropriate for these species, particularly species of the eastern U.S. Conversely, greatest number of species were predicted to be lost from most of the eastern half of the U.S.; National Forests in the southeastern U.S., particularly in Alabama, Mississippi, and Texas, may lose 25 to 50 of these tree species. Isolation of potential dynamics for tree species already native to northern North America demonstrated that a large pool of diverse species from the southeastern U.S. was predicted to have suitable climate space in Canada and the western U.S. It may be beneficial for managers to become familiar with tree species south or east of their regions, particularly climate-tolerant pine and oak species, to determine which ones are desirable to manage for the future.

Inner core backtracking by seismic waveform change reversals

The solid inner core, suspended within the liquid outer core and anchored by gravity, has been inferred to rotate relative to the surface of Earth or change over years to decades based on changes in seismograms from repeating earthquakes and explosions1,2. It has a rich inner structure3–6 and influences the pattern of outer core convection and therefore Earth’s magnetic field. Here we compile 143 distinct pairs of repeating earthquakes, many within 16 multiplets, built from 121 earthquakes between 1991 and 2023 in the South Sandwich Islands. We analyse their inner-core-penetrating PKIKP waves recorded on the medium-aperture arrays in northern North America. We document that many multiplets exhibit waveforms that change and then revert at later times to match earlier events. The matching waveforms reveal times at which the inner core re-occupies the same position, relative to the mantle, as it did at some time in the past. The pattern of matches, together with previous studies, demonstrates that the inner core gradually super-rotated from 2003 to 2008, and then from 2008 to 2023 sub-rotated two to three times more slowly back through the same path. These matches enable precise and unambiguous tracking of inner core progression and regression. The resolved different rates of forward and backward motion suggest that new models will be necessary for the dynamics between the inner core, outer core and mantle.

First automatic size measurements for the separation of dwarf birch and tree birch pollen in MIS 6 to MIS 1 records from Northern Germany.

During past glacial periods, the land cover of Northern Eurasia and North America repeatedly shifted between open steppe tundra and boreal/temperate forest. Tracking these changes and estimating the coverage of open versus forested vegetation in past glacial and interglacial landscapes is notoriously difficult because the characteristic dwarf birches of the tundra and the tree birches of the boreal and temperate forests produce similar pollen grains that are difficult to distinguish in the pollen record. One objective approach to separating dwarf birch pollen from tree birch pollen is to use grain size statistics. However, the required grain size measurements are time-consuming and, therefore, rarely produced. Here, we present an approach to automatic size measurement based on image recognition with convolutional neural networks and machine learning. It includes three main steps. First, the TOFSI algorithm is applied to detect and classify pollen, including birch pollen, in lake sediment samples. Second, a Resnet-18 neural network is applied to select the birch pollen suitable for measurement. Third, semantic segmentation is applied to detect the outline and the area and mean width of each detected birch pollen grain. Test applications with two pollen records from Northern Germany, one covering the Lateglacial-Early Holocene transition and the other covering the Mid to Late Pleistocene transition, show that the new technical approach is well suited to measure the area and mean width of birch pollen rapidly (>1000 per hour) and with high accuracy. Our new network-based tool facilitates more regular size measurements of birch pollen. Expanded analysis of modern birch pollen will help to better understand size variations in birch pollen between birch species and in response to environmental factors as well as differential sample preparation. Analysis of fossil samples will allow better quantification of dwarf birch versus tree birch in past environments.

Cryospheric and Oceanographic Evolution in the Arctic Makarov Basin Since the Early Pleistocene Revealed by Bulk Mineral Assemblages

AbstractWe present the glacial history of the Makarov Basin (western Arctic Ocean) during the last ∼1.1 Myr, with sediment provenances using the newly refined chronostratigraphy of core ARA03B‐41GC02. According to the principal component analysis of the bulk mineral assemblages, felsic minerals were dominant, and their ratios (K‐feldspar/plagioclase and quartz/feldspars) indicated that sediment supply to the Makarov Basin was mainly from the Siberian margin and partly from northern North America, including the Canadian Arctic. However, their occurrence did not vary significantly between interglacials and glacials due to the mixed sources. In contrast, clinopyroxene and dolomite indicated specific sediment origins from the eastern Siberian margin and northern North America, respectively. The clinopyroxene content followed an eccentricity cycle (∼100‐Kyr) during the early to middle Pleistocene, suggesting that the eustatic sea level changes may have influenced its input from the eastern Siberian margin. The dolomite, transported primarily by icebergs from the Arctic sector of the Laurentide Ice Sheet (LIS) in northern North America, has also followed the same cycle since the early Pleistocene. Thus, the mineralogical signals highlight that sediment origins and transport processes in the Makarov Basin were related to ice sheet evolution at the eccentricity cycle. In addition, dolomite deposition in the Makarov Basin began by the early Pleistocene (∼790 ka), ∼150 ka earlier than in previous North Atlantic records (∼640 ka), indicating the earlier LIS calving in the Arctic sector than in the Atlantic sector.

Impact of Preseason Climate Factors on Vegetation Photosynthetic Phenology in Mid-High Latitudes of the Northern Hemisphere.

During the period preceding the vegetation growing season (GS), temperature emerges as the pivotal factor determining phenology in northern terrestrial ecosystems. Despite extensive research on the impact of daily mean temperature (Tmean) during the preseason period, the influence of diurnal temperature range (DTR) on vegetation photosynthetic phenology (i.e., the impact of the plant photosynthetic cycle on seasonal time scale) has largely been neglected. Using a long-term vegetation photosynthetic phenology dataset and historical climate data, we examine vegetation photosynthetic phenology dynamics and responses to climate change across the mid-high latitudes of the Northern Hemisphere from 2001 to 2020. Our data reveal an advancing trend in the start of the GS (SOS) by -0.15 days per year (days yr-1), affecting 72.1% of the studied area. This is particularly pronounced in western Canada, Alaska, eastern Asia, and latitudes north of 60°N. Conversely, the end of the GS (EOS) displays a delaying trend of 0.17 days yr-1, impacting 62.4% of the studied area, especially northern North America and northern Eurasia. The collective influence of an earlier SOS and a delayed EOS has resulted in the notably prolonged length of the GS (LOS) by 0.32 days yr-1 in the last two decades, affecting 70.9% of the studied area, with Eurasia and western North America being particularly noteworthy. Partial correlation coefficients of the SOS with preseason Tmean, DTR, and accumulated precipitation exhibited negative values in 98.4%, 93.0%, and 39.2% of the study area, respectively. However, there were distinct regional variations in the influence of climate factors on the EOS. The partial correlation coefficients of the EOS with preseason Tmean, DTR, and precipitation were positive in 58.6%, 50.1%, and 36.3% of the region, respectively. Our findings unveil the intricate mechanisms influencing vegetation photosynthetic phenology, holding crucial significance in understanding the dynamics of carbon sequestration within terrestrial ecosystems amidst climate change.

Historical Demography and Climate Driven Range Shifts in the Blue-spotted Salamander Under the Climate Change Scenarios

This study integrates phylogeography with distributional analysis to understand the demographic history and range dynamics of a limited dispersal capacity amphibian species, Blue-spotted Salamander (Ambystoma laterale), under several climate change scenarios. For this we used an ecological niche modeling approach, together with Bayesian based demographic analysis, to develop inferences regarding this species' demographic history and range dynamics. The current model output was mostly congruent with the present distribution of the Blue-spotted Salamander. However, under both the Last Interglacial and the Last Glacial Maximum bioclimatic conditions, the model predicted a substantially narrower distribution than the present. These predictions showed almost no suitable area in the current distribution range of the species during almost the last 22.000 y before present (ybp). The predictions indicated that the distribution of this species shifted from eastern coast of northern North America to the southern part of the current distribution range of the species. The Bayesian Skyline Plot analysis, which provided good resolution of the effective population size changes over the Blue-spotted Salamander history, was mostly congruent with ecological niche modeling predictions for this species. This study provides the first investigation of the Blue-spotted Salamander’s late-Quaternary history based on ecological niche modeling and Bayesian-based demographic analysis. In terms of the main result of this study, we found that the species' present genetic structure has been substantially affected by past climate changes, and this species has reached current distribution range almost from nothing since the Last Glacial Maximum.

The variations of ENSO teleconnections during the Last Interglacial based on PMIP4 simulations

How the remote influences of El Niño-Southern Oscillation (ENSO) may vary in a warmer future remains a hot topic but still elusive. Based on the outputs from the Paleoclimate Modeling Intercomparison Project Phase 4, here we investigated the variations of ENSO teleconnections in boreal winter during the Last Interglacial (LIG), which shares large similarities with the projected climatic features in the 21st century. Our results suggested that the ENSO-temperature teleconnections on average weakened by ∼13.4% during the LIG relative to the preindustrial, whereas the response of precipitation amplified by ∼5.0%. However, there are large regional discrepancies in the variations of ENSO teleconnections in terms of the sign and amplitude. For example, we observed significant ENSO-temperature relationship changes at the high latitudes during the LIG, with a depressed linkage over northern North America but enhanced linkage over the high latitudes of Eurasia. The most profound change in ENSO-precipitation teleconnection occurred over the tropics during the LIG, characterized by a weaker response over the equatorial Pacific Ocean whereas a stronger response over the Maritime Continent and adjacent oceans. Regarding atmospheric circulations, we found that the ENSO-driven Walker Circulations over the Pacific and the Indian Ocean shifted westward during the LIG, whereas the descending branch of the ENSO-driven Atlantic Walker Circulation shifted eastward. Our results provide a model-based scenario for the variations of ENSO teleconnections during the LIG, but the underlying mechanisms deserve further investigation in the future.

Global epidemiology of epithelial ovarian cancer.

Globally, ovarian cancer is the eighth most common cancer in women, accounting for an estimated 3.7% of cases and 4.7% of cancer deaths in 2020. Until the early 2000s, age-standardized incidence was highest in northern Europe and North America, but this trend has changed; incidence is now declining in these regions and increasing in parts of eastern Europe and Asia. Ovarian cancer is a very heterogeneous disease and, even among the most common type, namely epithelial ovarian cancer, five major clinically and genetically distinct histotypes exist. Most high-grade serous ovarian carcinomas are now recognized to originate in the fimbrial ends of the fallopian tube. This knowledge has led to more cancers being coded as fallopian tube in origin, which probably explains some of the apparent declines in ovarian cancer incidence, particularly in high-income countries; however, it also suggests that opportunistic salpingectomy offers an important opportunity for prevention. The five histotypes share several reproductive and hormonal risk factors, although differences also exist. In this Review, we summarize the epidemiology of this complex disease, comparing the different histotypes, and consider the potential for prevention. We also discuss how changes in the prevalence of risk and protective factors might have contributed to the observed changes in incidence and what this might mean for incidence in the future.

Agro-nutritionnel Characterisation of Quinoa (Chenopodium quinoa, Willd.)

Quinoa (Chenopodium quinoa Willd.) originated in the Andean region of South America; is a dicotyledonous species for seeds and, therefore, is not known as a cereal grain and is a pseudograin, which is introduced nowadays as a new crop in the world. Quinoa is an annual herbaceous plant belongs to Amaranthaceae family, but formerly placed in Chenopodiaceae family. It’s well adapted to a wide range of climatic conditions and has significant potential for increased production as a new crop in the Mediterranean region and in other parts of the world, including northern Europe, North America, Asia, and Africa. Quinoa is associated with exceptional grain nutritional quality and is highly valued for its ability to tolerate abiotic stresses. The protein content of quinoa grains is higher than other cereals while it has better distribution of essential amino acids. It can be used as an alternative to milk proteins. Additionally, quinoa contains a high amount of essential fatty acids, minerals, vitamins, dietary fibers, and carbohydrates with beneficial hypoglycemic effects while being gluten-free. e. In addition, it is found to contain a number of bioactive chemical compounds whose various therapeutic properties are actively studied in the scientific field. Quinoa is sought in several industries whether it is the food industry, pharmacology, cosmetics, etc., as a plant (use of leaves, seeds, or stem) or these extracts (saponins, vegetable oil and essential).

Glacial inception through rapid ice area increase driven by albedo and vegetation feedbacks

Abstract. We present transient simulations of the last glacial inception using the Earth system model CLIMBER-X with dynamic vegetation, interactive ice sheets, and visco-elastic solid Earth responses. The simulations are initialized at the middle of the Eemian interglacial (125 kiloyears before present, ka) and run until 100 ka, driven by prescribed changes in Earth's orbital parameters and greenhouse gas concentrations from ice core data. CLIMBER-X simulates a rapid increase in Northern Hemisphere ice sheet area through MIS5d, with ice sheets expanding over northern North America and Scandinavia, in broad agreement with proxy reconstructions. While most of the increase in ice sheet area occurs over a relatively short period between 119 and 117 ka, the larger part of the increase in ice volume occurs afterwards with an almost constant ice sheet extent. We show that the vegetation feedback plays a fundamental role in controlling the ice sheet expansion during the last glacial inception. In particular, with prescribed present-day vegetation the model simulates a global sea level drop of only ∼ 20 m, compared with the ∼ 35 m decrease in sea level with dynamic vegetation response. The ice sheet and carbon cycle feedbacks play only a minor role during the ice sheet expansion phase prior to ∼ 115 ka but are important in limiting the deglaciation during the following phase characterized by increasing summer insolation. The model results are sensitive to climate model biases and to the parameterization of snow albedo, while they show only a weak dependence on changes in the ice sheet model resolution and the acceleration factor used to speed up the climate component. Overall, our simulations confirm and refine previous results showing that climate–vegetation–cryosphere feedbacks play a fundamental role in the transition from interglacial to glacial states characterizing Quaternary glacial cycles.