Great Basin Desert Research Articles

Lithium from clay: Assessing the environmental impacts of extraction

The burgeoning electric vehicle (EV) sector in the United States (US) is expected to drive up the demand for lithium, a critical element for EV batteries. Lithium-rich clays in the Nevada desert emerge as a prospective US-based domestic source. This study employs Life Cycle Assessment (LCA) to examine the environmental aspects of extracting lithium from this source. Among the two evaluated routes, acid leaching was more energy-efficient (35 MJ/kg LCE (Lithium Carbonate Equivalent) than roasting (200 MJ/kg LCE), based on pilot plant data. When compared to conventional methods like spodumene-based extraction, acid leaching shows reductions across almost every category, with notable decreases in high-magnitude impacts like Global Warming (48 %), Freshwater Ecotoxicity (15 %), and Smog (69 %). Water consumption is the only category that increases, rising by 79 %. Insights from this study on upstream impacts of lithium from clay could help inform sourcing decisions downstream, in the battery and EV sector.

The hotter the better: high mean annual temperature, not seed predation, hastens the decline of invasive Bromus tectorum

Bromus tectorum invasion degrades biodiversity and ecosystem functioning in the Great Basin Desert. To explain, predict, and manage B. tectorum invasion, we must understand the biotic and abiotic factors that influence its establishment and persistence. We explored interactions between two key constraints for invaders in general and B. tectorum in particular: post-dispersal seed predation and climate, including mean annual temperature, rainfall, snowfall, and aridity. At six study sites in undisturbed, climax Artemisia tridentata communities across northern Nevada and Utah, we performed one-time additions of 100 B. tectorum seeds to microsites outfitted with either a dummy (“open”) cage that exposed seeds to rodent foraging, or a functional (“closed”) cage that protected them from rodent foraging. Living Bromus tectorum plants within experimental cages were censused one and 5 years after seed additions. At both 1- and 5-years censuses, and regardless of climate, B. tectorum densities were similar in open and closed microsites, suggesting that rodent foraging did not affect B. tectorum establishment or persistence. Compared to 1-year censuses, B. tectorum counts declined by 47% across all sites after 5 years, but declines were sharpest at sites with the highest mean annual temperatures. Taken together, our findings suggest that undisturbed, climax A. tridentata communities can resist B. tectorum expansion, and this resistance increases with mean annual temperature, not rodent foraging. We suggest that controlling nascent populations of B. tectorum may be particularly urgent in intact climax A. tridentata communities in relatively cool climates, where community-level resistance against B. tectorum persistence is lowest.

Remote sensing reveals the importance of seminatural habitat and irrigation on aphid biocontrol in arid agroecosystems

Abstract Remote sensing and spatial analyses are increasingly used to understand the role of seminatural habitats in biocontrol, but knowing how to best leverage these tools is a persistent challenge. In arid agroecosystems, irrigation often exaggerates the differences between crop fields and their interspaces. Weeds adjacent to irrigated fields are thus often some of the only persistent vegetation. Remote sensing may be essential to capture the effect of this fine‐scale variation on pest biocontrol. We examined the role of land‐cover in determining the degree of aphid pest pressure and biocontrol in irrigated alfalfa fields in the Great Basin Desert (Nevada, USA). We experimentally manipulated predator densities to determine true agents of aphid biocontrol in this system. We then assessed land‐cover and spatial scale using alternative methods to determine the approaches that best defined the combined direct and indirect effects of seminatural habitat on aphid pest suppression. A remote‐sensing approach revealed the importance of land‐cover to aphid biocontrol more clearly than conventional vegetation surveys. In particular, remote sensing revealed that weedy patches within alfalfa fields reduced aphid densities, whereas flood irrigation increased aphid densities. Our experiments confirmed that coccinellid beetles are important aphid biocontrol agents. Coccinellids were positively associated with weedy land‐cover that was spatially close to alfalfa fields, particularly in the spring. Other predator taxa were also associated with distinct landscape features, though these associations varied between spring and fall. Solution: Weedy seminatural habitat near alfalfa fields, occurring along field margins and the banks of irrigation ditches, was positively associated with the density of coccinellid beetles and associated aphid pest suppression. Remote sensing excelled at identifying these areas and their effects, highlighting its utility as a management tool. Preserving these weedy areas can enhance aphid biocontrol, but farmers must consider potential trade‐offs between the control of insect‐pests and weeds.

Rodent competition and fire alter patterns of mound and disk formation of western harvester ants.

Consumers exert top-down controls on dryland ecosystem function, but recent increases in fire activity may alter consumer communities in post-fire environments. Native consumers, including ants and rodents, likely have critical roles in defining post-fire plant community assembly and resilience to biological invasions. This study aimed to understand how western harvester ants (Pogonomyrmex occidentalis) that form mounds and large vegetation-free disks that significantly influence plant community structure in the Great Basin Desert respond to fire and rodent community abundance. We tested this by installing treatment plots that excluded or allowed rodents and were burned or unburned in a full factorial design. We measured ant disk and mound size and density in each experimental plot. Fire increased ant mound density by 126% compared to unburned plots. Rodent presence decreased mound density by 59%, mound diameter by 13%, and mound height by 166%. We also show an interaction where the adverse effects of rodents on ant disk density were greater in burned than in unburned plots. The results suggest that booms in rodent populations are likely to have suppressive effects on ant mound and disk formation in native shrublands but that harvester ants may be released from rodent competition with the emergence of invasive grass-fire cycles.

Matters of Distance: On Consent, Documentary Practices, and the Nevada Desert

Matters of Distance: On Consent, Documentary Practices, and the Nevada Desert

Kit foxes demonstrate adaptive compromise characteristics under intraguild predation pressure by coyotes in the Great Basin desert

Coyotes (Canis latrans) are believed to contribute to declining kit fox (Vulpes macrotis) numbers in the Great Basin desert through intraguild predation. Intraguild prey have been shown to exhibit adaptive compromise, whereby an animal increases selection for risky, but food-rich areas during times of food stress (i.e. winter). We evaluated the habitat selection of kit foxes in the Great Basin desert to elucidate if they demonstrated adaptive compromise as a method of coexisting with coyotes. We created 2nd order resource selection functions to analyze kit fox habitat selection associated with coyote relative probability of use (RPU), prey abundance, and type of soil substrate. In the summer, we found that kit fox selection for areas of relatively more abundant prey was not significant, and there was a small positive selection for coyote RPU. In the winter, we found a positive relationship between kit fox selection and prey abundance as well as a stronger selection for coyote RPU. These findings do follow the pattern of adaptive compromise. We also found kit foxes selected for silty and sandy soils, which are conducive to den construction, as they use dens seasonally for breeding but also year-round for multiple uses, including refugia from predators and extreme heat. Soil substrate appeared to be an important factor impacting kit fox habitat selection.

The Bee Communities of Young Living Lavender Farm, Mona, Utah, USA

It is now widely recognized that bees are among the most important pollinators worldwide, yet the bee faunas of many regions and habitats remain inadequately documented. The Great Basin Desert in North America is thought to host some of the richest bee communities in the world, as indicated by several studies documenting diverse bee faunas in the region’s natural habitats. However, limited attention has been given to the bee communities present on agricultural lands within the Great Basin Desert. Here, we describe a rich bee community housed at the Young Living Lavender Farm in Juab County, Utah, near the eastern edge of the Great Basin Desert. Our survey of bees on this farm identified 68 bee species across 22 genera. This represents 34% of the bee species known from the county, including 34 new county records. Among the numerous flower species cultivated at the farm, we found that lavender supported the richest bee community, with 32 species collected from cultivated lavender fields. While lavender is frequently recommended for homeowners to plant in support of pollinators, our study is among the first to provide a list of bee species that visit lavender in western North America. Furthermore, our results demonstrate that agricultural lands, particularly those implementing pollinator-friendly farming practices, can support rich bee communities in the Great Basin Desert.

Microbiology of Big Soda Lake, a multi-extreme meromictic volcanic crater lake in the Nevada desert.

Big Soda Lake, Nevada, is a multi-extreme meromictic lake, whose hypersaline hyperalkaline bottom waters feature permanent anoxia and high concentrations of arsenic, sulphide and ammonia. These properties make Big Soda Lake-and the adjacent Little Soda Lake-a fascinating system for exploring life's boundaries, discovering novel microbial taxa and identifying biotechnologically useful strains. To date, the taxonomic diversity and metabolic capabilities of microorganisms in this system remain largely unknown. Here, we fill this gap using microbiome surveys across the Big and Little Soda Lake water columns, including 16S rRNA sequencing, fungal ITS2 sequencing and gene- and genome-resolved metagenomics. We accompany these surveys with measurements of salinity, pH, temperature, oxygen, ammonium and ammonia concentrations. Our analyses reveal rich bacterial communities, taxonomically and functionally differentiated along Big Soda Lake's oxycline and, to lesser extent, between lakes. Fungal communities were dominated by a small number of families, while nearly no archaea were detected. Pathways related to perchlorate reduction, anoxygenic phototrophy, fermentation, dissimilatory metabolism of arsenite/arsenate, sulphur compounds, nitrogen compounds and hydrogen, were particularly prevalent. A total of 129 high-quality bacterial and archaeal metagenome-assembled genomes (completeness ≥ 80%, contamination ≤ 5%) were recovered, yielding insight into the taxonomic distribution of microbial metabolic pathways.

Elevated atmospheric CO2 drives decreases in stable soil organic carbon in arid ecosystems: Evidence from a physical fractionation and organic compound analysis.

The increasing concentration of CO2 in the atmosphere is perturbing the global carbon (C) cycle, altering stocks of organic C, including soil organic matter (SOM). The effect of this disturbance on soils in arid ecosystems may differ from other ecosystems due to water limitation. In this study, we conducted a density fractionation on soils previously harvested from the Nevada Desert FACE Facility (NDFF) to understand how elevated atmospheric CO2 (eCO2 ) affects SOM stability. Soils from beneath the perennial shrub, Larrea tridentata, and from unvegetated interspace were subjected to a sodium polytungstate density fractionation to separate light, particulate organic matter (POM, <1.85 g/cm3 ) from heavier, mineral associated organic matter (MAOM, >1.85 g/cm3 ). These fractions were analyzed for organic C, total N, δ13 C and δ15 N, to understand the mechanisms behind changes. The heavy fraction was further analyzed by pyrolysis GC/MS to assess changes in organic compound composition. Elevated CO2 decreased POM-C and MAOM-C in soils beneath L. tridentata while interspace soils exhibited only a small increase in MAOM-N. Analysis of δ13 C revealed incorporation of new C into both POM and MAOM pools indicating eCO2 stimulated rapid turnover of both POM and MAOM. The largest losses of POM-C and MAOM-C observed under eCO2 occurred in soils 20-40 cm in depth, highlighting that belowground C inputs may be a significant driver of SOM decomposition in this ecosystem. Pyrolysis GC/MS analysis revealed a decrease in organic compound diversity in the MAOM fraction of L. tridentata soils, becoming more similar to interspace soils under eCO2 . These results provide further evidence that MAOM stability may be compromised under disturbance and that SOC stocks in arid ecosystems are vulnerable under continued climate change.

Coyotes in the Great Basin desert do not exhibit a spatial response following the removal of anthropogenic water sources

Coyote (Canis latrans) range expansion into desert ecosystems has highlighted the role of anthropogenic water sources in arid ecosystems. Despite hypotheses that additional water facilitated this expansion, previous studies reported that coyotes did not exhibit a spatial or dietary response to removal of anthropogenic water. We used GPS data to examine if coyotes responded to water removal at a finer spatial scale than previously investigated. Our integrated step selection analysis did not find evidence that coyotes adjusted their distance to water following water removal. Vegetation was an important factor in habitat selection of coyotes, with riparian and agricultural areas being the most selected among vegetation types. Coyotes selected for locations where hunting and trapping was prohibited. Possibly the cause of increased coyote abundance in our study area was not due to the introduction of anthropogenic water sources but rather due to the cessation of regional lethal predator control programs. These two management decisions both occurred in the 1970s, therefore, their influences on the subsequent increase of coyote abundance may have been conflated. Our results, in combination with previous studies, provide evidence that coyotes are desert-adapted carnivores that do not rely on anthropogenic water sources.

Efficient pollen grain classification using pre-trained Convolutional Neural Networks: a comprehensive study

Pollen identification is necessary for several subfields of geology, ecology, and evolutionary biology. However, the existing methods for pollen identification are laborious, time-consuming, and require highly skilled scientists. Therefore, there is a pressing need for an automated and accurate system for pollen identification, which can be beneficial for both basic research and applied issues such as identifying airborne allergens. In this study, we propose a deep learning (DL) approach to classify pollen grains in the Great Basin Desert, Nevada, USA. Our dataset consisted of 10,000 images of 40 pollen species. To mitigate the limitations imposed by the small volume of our training dataset, we conducted an in-depth comparative analysis of numerous pre-trained Convolutional Neural Network (CNN) architectures utilizing transfer learning methodologies. Simultaneously, we developed and incorporated an innovative CNN model, serving to augment our exploration and optimization of data modeling strategies. We applied different architectures of well-known pre-trained deep CNN models, including AlexNet, VGG-16, MobileNet-V2, ResNet (18, 34, and 50, 101), ResNeSt (50, 101), SE-ResNeXt, and Vision Transformer (ViT), to uncover the most promising modeling approach for the classification of pollen grains in the Great Basin. To evaluate the performance of the pre-trained deep CNN models, we measured accuracy, precision, F1-Score, and recall. Our results showed that the ResNeSt-110 model achieved the best performance, with an accuracy of 97.24%, precision of 97.89%, F1-Score of 96.86%, and recall of 97.13%. Our results also revealed that transfer learning models can deliver better and faster image classification results compared to traditional CNN models built from scratch. The proposed method can potentially benefit various fields that rely on efficient pollen identification. This study demonstrates that DL approaches can improve the accuracy and efficiency of pollen identification, and it provides a foundation for further research in the field.

Field-work reveals a novel function for MAX2 in a native tobacco's high-light adaptions.

Laboratory studies have revealed that strigolatone (SL) and karrikin (KAR) signalling mediate responses to abiotic and biotic stresses, and reshape branching architecture that could increase reproductive performance and crop yields. To understand the ecological function of SL and KAR signalling, transgenic lines of wild tobacco Nicotiana attenuata, silenced in SL/KAR biosynthesis/signalling were grown in the glasshouse and in two field plots in the Great Basin Desert in Utah over four field seasons. Of the lines silenced in SL and KAR signalling components (irMAX2, irD14, irKAI2 and irD14 × irKAI2 plants), which exhibited the expected increases in shoot branching, only irMAX2 plants showed a strong leaf-bleaching phenotype when grown in the field. In the field, irMAX2 plants had lower sugar and higher leaf amino acid contents, lower lifetime fitness and were more susceptible to herbivore attack compared to wild-type plants. These irMAX2 phenotypes were not observed in glasshouse-grown plants. Transcriptomic analysis revealed dramatic responses to high-light intensity in irMAX2 leaves in the field: lutein contents decreased, and transcriptional responses to high-intensity light, singlet oxygen and hydrogen peroxide increased. PAR and UV-B manipulations in the field revealed that the irMAX2 bleaching phenotype is reversed by decreasing PAR, but not UV-B fluence. We propose that NaMAX2 functions in high-light adaptation and fitness optimisation by regulating high-light responses independently of its roles in the SL and KAR signalling pathways. The work provides another example of the value of studying the function of genes in the complex environments in which plants evolved, namely nature.

Movement patterns and habitat use for the sympatric species: Gambelia wislizenii and Aspidoscelis tigris.

Movement is an important characteristic of an animal's ecology, reflecting the perception of and response to environmental conditions. To effectively search for food, movement patterns likely depend on habitat characteristics and the sensory systems used to find prey. We examined movements associated with foraging for two sympatric species of lizards inhabiting the Great Basin Desert of southeastern Oregon. The two species have largely overlapping diets but find prey via different sensory cues, which link to their differing foraging strategies-the long-nosed leopard lizard, Gambelia wislizenii, is a visually-oriented predator, while the western whiptail, Aspidoscelis tigris, relies more heavily on chemosensory cues to find prey. Using detailed focal observations, we characterized the habitat use and movement paths of each species. We placed markers at the location of focal animals every minute for the duration of each 30-min observation. Afterward, we recorded whether each location was in the open or in vegetation, as well as the movement metrics of step length, path length, net displacement, straightness index, and turn angle, and then made statistical comparisons between the two species. The visual forager spent more time in open areas, moved less frequently over shorter distances, and differed in patterns of plant use compared to the chemosensory forager. Path characteristics of step length and turn angle differed between species. The visual predator moved in a way that was consistent with the notion that they require a clear visual path to stalk prey whereas the movement of the chemosensory predator increased their chances of detecting prey by venturing further into vegetation. Sympatric species can partition limited resources through differences in search behavior and habitat use.

Fine‐scale spatial genetic structure in a locally abundant native bunchgrass (Achnatherum thurberianum) including distinct lineages revealed within seed transfer zones

AbstractAnalyses of the factors shaping genetic variation in widespread plant species are important for understanding the evolutionary history and local adaptation and have applied significance for guiding conservation and restoration decisions. Thurber's needlegrass (Achnatherum thurberianum) is a widespread, locally abundant grass that inhabits heterogeneous arid environments of western North America and is of restoration significance. It is a common component of shrubland steppe communities in the Great Basin Desert, where drought, fire, and invasive grasses have degraded natural communities. Using a reduced representation sequencing approach, we generated SNP data at 5677 loci across 246 individuals from 17 A. thurberianum populations spanning five previously delineated seed zones from the western Great Basin. Analyses revealed a pronounced population genetic structure, with individuals forming consistent geographical clusters across a variety of population genetic analyses and spatial scales. Low levels of genetic diversity within populations, as well as high population estimates of linkage disequilibrium and relatedness, were consistent with self‐fertilization as a contributor to population differentiation. Variance partitioning and partial redundancy analysis (pRDA) indicated local adaptation to environment as additionally influencing the spatial distribution of genetic variation. The environmental variables driving these results were similar to those implicated in recent genecological work which inferred local adaptation for seed zone delineation. Our analyses also revealed a complex evolutionary history of A. thurberianum in the Great Basin, where previously delineated seed zones contain distantly related populations. Our results indicate evolutionary history, mating system, and differentiation across distinct geographic and environmental scales have shaped genetic variation in A. thurberianum and illustrate how numerous aspects of population genetic variation might require consideration for restoration planning.

Science and Public Engagement in National Parks: Examples and Advice from Young Scientists

Science and Public Engagement in National Parks: Examples and Advice from Young Scientists

Black bear density and habitat use variation at the Sierra Nevada‐Great Basin Desert transition

AbstractIn the first 2 decades of the twenty‐first century, American black bear (Ursus americanus) populations rebounded with range expansions into areas where the species was previously extirpated. While there are a number of factors that limit range expansion, habitat quality and availability are among the most important. Such factors may be particularly important in western Nevada, USA, at the transition zone of the Sierra Nevada and the Great Basin Desert. We deployed a multi‐faceted data collection system including motion‐sensitive cameras, noninvasive hair sampling and genotyping, and global positioning system (GPS) tracking. We analyzed data using spatial capture‐recapture to estimate population density and dynamic occupancy models to estimate habitat use. Black bear habitat use and density were substantially higher in the Sierra Nevada than the Great Basin Desert and had strong positive relationships with the presence of conifer land cover in the transition zone. The average black bear density was &gt;4 times higher in the mixed‐conifer forests of the Sierra Nevada (12.4 bears/100 km2) than in desert mountain ranges with piñon (Pinus monophylla)‐juniper (Juniperus spp.) woodland (2.7 bears/100 km2). The low‐elevation shrub and grassland portions of the study area had even lower estimated black bear density (0.6 bears/100 km2) and probability of use (0.03, 95% CI = 0.00–0.09). Across these spatially variable configurations in black bear density, we estimated the population size to be 418 individuals (95% CI = 239–740). Declining density towards the range edge, coupled with a relatively stable range of black bears in Nevada observed since 2000, suggests that further species range expansion into the western Great Basin may be limited by habitat quality and availability.

Modern approaches for leveraging biodiversity collections to understand change in plant-insect interactions

Research on plant-pollinator interactions requires a diversity of perspectives and approaches, and documenting changing pollinator-plant interactions due to declining insect diversity and climate change is especially challenging. Natural history collections are increasingly important for such research and can provide ecological information across broad spatial and temporal scales. Here, we describe novel approaches that integrate museum specimens from insect and plant collections with field observations to quantify pollen networks over large spatial and temporal gradients. We present methodological strategies for evaluating insect-pollen network parameters based on pollen collected from museum insect specimens. These methods provide insight into spatial and temporal variation in pollen-insect interactions and complement other approaches to studying pollination, such as pollinator observation networks and flower enclosure experiments. We present example data from butterfly pollen networks over the past century in the Great Basin Desert and Sierra Nevada Mountains, United States. Complementary to these approaches, we describe rapid pollen identification methods that can increase speed and accuracy of taxonomic determinations, using pollen grains collected from herbarium specimens. As an example, we describe a convolutional neural network (CNN) to automate identification of pollen. We extracted images of pollen grains from 21 common species from herbarium specimens at the University of Nevada Reno (RENO). The CNN model achieved exceptional accuracy of identification, with a correct classification rate of 98.8%. These and similar approaches can transform the way we estimate pollination network parameters and greatly change inferences from existing networks, which have exploded over the past few decades. These techniques also allow us to address critical ecological questions related to mutualistic networks, community ecology, and conservation biology. Museum collections remain a bountiful source of data for biodiversity science and understanding global change.

Postfire restoration seeding success increases with early fall seeding and simulated precipitation in the Great Basin Desert of North America

Climate forecasts and disturbance mapping increasingly inform strategies for ecological restoration practices. Our study objectives were to understand how a postfire rehabilitation seed mix responds to fire, seeding timing, and changes in fall precipitation timing due to climate change. We planted seeds commonly used in the Great Basin Desert of North America on soil cores in a randomized block design. We imposed two experimental treatments, experimental fire (burned seedbeds or unburned seedbeds) and timing of seeding with simulated precipitation (early September vs. mid‐October) in a two‐way factorial design. We measured seedling emergence (1 month posttreatment), plant density, biomass, and seed production. Early seeding and precipitation reduced seedling emergence over 2‐fold but increased total plant density (3‐fold), biomass (13‐fold), and seed production (140‐fold) compared to delayed seeding and precipitation applications. Antelope bitterbrush was the only species with a negative response to early seeding and precipitation, with a decrease in both density and biomass (over 2‐fold) by the end of the study. Burned seedbeds overall had little effect on measured outcomes for the total plant community. Burned seedbeds decreased forb seedling emergence 2‐fold and alfalfa and Lewis blue flax density almost 3‐fold but increased overall forb seed production 7‐fold while other species and functional groups had minimal responses. Earlier seeding and precipitation interacted with the effects of burned seedbeds to increase biomass of Wyoming big sagebrush and western yarrow. The positive response of species to earlier fall seeding and precipitation underscores the importance of adapting our restoration practices for changing climate conditions.

Editorial: will the future be sustainable or just 'greenwash' printed in organic ink on sustainably-sourced glossy brochures?

Editorial:will the future be sustainable or just 'greenwash' printed in organic ink on sustainably-sourced glossy brochures? Daniel Blackburn, Editor and Declan Owens, Guest Editor The COP26 talks were a failure: a 'parade of inaction, false solutions and greenwash from rich governments and corporations'. But the event was not meaningless and heralded also a 'historic moment of growth in power and solidarity for the climate justice movement' This will ultimately play a critical role to overcome what remains of the suspicion of 'middle class' environmentalists by a working class cynical that their jobs and lives are being 'recklessly' pushed aside. De-industrialisation is not a new idea for many in Europe and North America, and their experience of it the first time around was not encouraging. And yet history is repeating, as Adrian Kane and Yvonne O'Callaghan observe small towns across the Irish midlands that are beginning 'to resemble the North of England's bleak post-industrial wastelands', as a local fossil fuel industry there is run down. There have been 'expensive government-led initiatives' to mitigate job losses but our contributors report the case of a nation-wide company displacing a local established business after receiving a grant from the local funding pool, seemingly the opposite of what would be intended. Huw Beynon and Ray Hudson remind us of just how bleak the impact was when the State failed to make any or sufficient provision to deal with the aftermath of the coal industry closures in the UK. Meanwhile, there are still many complaining about China and India's reliance on coal, though increasing recognition that over time it is the West that has contributed massively more to climate emissions. How can unions representing workers in these industries find agreement with climate activists? Sindhu Menon finds India's mining union leaders concerned for the future of workers with non-transferable skills who live on land that is degraded for farming and where water is scarce. Mine closure here means job losses, 'starvation', and 'disaster' for the coal belt economy. Georgia Montague-Nelson explains that livestock production also contributes 'over one-third of all human caused greenhouse gas emissions'. A set of trade union proposals for the sector developed by the IUF and GLI demonstrates a real potential for engagement with climate activists around shared ideas about decentralisation and redistribution and reducing the size of supply chains and the role of giant global corporations in livestock and agriculture. David Bacon shares with us a small selection of his photography collection documenting the lives and working conditions of fruit-pickers left their former homes in Mexico to avoid already 'devastating' climate impacts there, but are now facing increasingly aggressive heat under a changing climate in their adopted US. Sean McManus from the IAFF represents another group of workers who face the burning heat head-on. McManus describes how Canada's notoriously cold climate is now increasingly juxtaposed with extraordinary peaks of heat during summer that can surpass even the highest ever temperatures recorded in the Nevada desert. Firefighters are dealing with novel climate effects at first hand, including more ferocious wildfires but also torrential rains and flooding. Every time they respond to such a disaster, firefighters 'see very plainly whether there are adequate front line resources or not'. Returning to industrial and energy questions, Diana Junquera Curiel investigates crucial industrial and technological aspects of a sustainable future, looking at battery and solar production, but tracing concerns through these new industries' supply chains leads us straight to the Xinjiang region of China, where forced labour allegations are raised with regard to its solar panel production facilities. As if to underscore trade union concerns that industrial workers might ultimately be short¬changed by the transition to a sustainable future, trade unionists in the UK were stunned weeks ago when a major ferry company informed its staff by recorded video message (with no prior notice) that their jobs had ended and they would be escorted from their vessels. Professor Keith Ewing finds 'no shortage of international standards', but a lack of actually legally enforceable rights. It is the massive double standard between the glossy proclamation and the lack of any protection in...

Iterative species distribution modeling results in the discovery of novel populations of a rare cold desert perennial

Niche modeling for rare and range-restricted species can generate inaccurate predictions leading to an overestimation of a species geographic distribution. We used an iterative ensemble modeling approach and model-stratified field surveys to improve niche model formulation and better understand the ecological drivers of Ivesia webberi distribution. I. webberi is a US federally threatened herbaceous species, narrowly distributed in the western Great Basin Desert. Niche models for I. webberi were fitted using 10 replicates each of 6 modeling algorithms, while geographical projections of habitat suitability were generated using weighted ensembles of models with optimal performance. The resulting model projections were used to guide field surveys for 5 yr, generating additional spatial data, which were added to the existing dataset for subsequent modeling. Model performance across iterations was investigated and niche differences in the spatial dataset were explored. Model-guided field surveys resulted in the discovery of several new locations of I. webberi and an expansion of the species known range by 63 km. Model performance was higher in the earlier overfitted niche models. Overfitting was corrected in the final models, and predicted habitat suitability reduced from 5.98% in the 2015 model to 3.34% in the 2020 model. Findings show that I. webberi niche is associated with biotic, topographic and bioclimatic variables. Furthermore, a partial overlap was observed between environmental conditions of the initial and the new locations (Schoener’s D = 0.47), which can be decomposed into 93% of niche stability. This indicates that the majority of the newly discovered locations are within the environmental niche of the initial data.