Recent ucb_espm_eco_oapdeposits items

Climate change increases risks of wildfire and biome shifts in United States national parks in California

Wed, 26 Aug 2026 00:00:00 +0000

Human-caused climate change has increased wildfire above natural levels across extensive areas of the world and caused vegetation biome shifts, detected and attributed from field observations. These changes threaten ecosystem integrity, yet detailed spatial patterns of risks remain unknown. We identify high risk areas in the globally unique ecosystems of Yosemite and three other United States national parks in California through analyses at 10 m spatial resolution. Our results reveal that climate change increased national park average temperatures up to 2.1 °C above pre-industrial levels from 1895 to 2023, exceeding the global average increase of 1.2 ± 0.1 °C. Forests in the region naturally require periodic fire but suppression generated severe fire risks on 6%–13% of park area by 2024. Under the highest emissions scenario (+4.6 °C–5 °C locally), climate change could shift potential biomes hundreds of meters upslope, on up to half of park area, increase fire frequencies 150%–350%,...

Wildlife movement responses to the press–pulse–pause of the Anthropocene

Wed, 26 Aug 2026 00:00:00 +0000

Wildlife is increasingly forced to share space with humans, facing disturbances that operate across different spatial and temporal scales. The press-pulse framework, originally developed in the disturbance ecology literature, distinguishes between long-term sustained 'presses' and more acute 'pulses'. Because pulses occur during ongoing press conditions, their ecological effects depend on how they interact with that background, helping explain why certain disturbances result in transient, localized changes, while others lead to lasting, widespread impacts. Here, we expand this framework by applying it to regimes of human disturbances, and incorporating 'pauses' as a third category. Pulses and pauses (e.g. episodes of extreme weather, or drastic changes in human mobility) can substantially affect wildlife behaviour, yet their effects are often modulated by background 'press' conditions. We offer a conceptual framework for disentangling effects across space and time and highlight...

Vegetation responses to air dryness amplify future land surface warming

Thu, 20 Aug 2026 00:00:00 +0000

Temperature exerts a first-order control on vegetation photosynthesis and transpiration. Yet most studies investigating temperature impacts on plants rely on near-surface air temperature, rather than canopy temperature—the temperature plants actually experience. Because canopy temperature directly regulates ecosystem function, it provides a more accurate measure of vegetation–climate interactions. Combining Earth System Model (ESM) simulations and satellite observations in a dual emergent constraint, here we show that canopy temperature is projected to increase substantially more than air temperature (~0.11-degrees more or a 16% increase in their difference) over the 21st century. The ESM ensemble median fails to capture these stronger increases in the majority of vegetated regions. We find that the largest projected increases in the difference between canopy and air temperature are predicted to occur in regions where elevating moisture stress—particularly rising vapor pressure...

Divergent carbon use efficiency-growth rate tradeoff in popular biological growth models

Wed, 22 Jul 2026 00:00:00 +0000

Abstract. Carbon use efficiency (CUE) is an important trait emerging from processes regulating biological growth. CUE can be computed either based on the growth of structural biomass or total biomass divided by substrate uptake rate. Nonequilibrium thermodynamics and observations suggest that, for an exponentially growing population of cells, structural biomass CUE should first increase, then peak, and finally decrease with specific growth rate; meanwhile, total biomass CUE increases asymptotically with specific growth rate. We compared predictions from six popular models that are often used for plant and microbial growth in existing ecosystem models. We found that, for an exponentially growing population of biological cells, (1) the source-driven Pirt and Compromise models predict that structural biomass CUE increase asymptotically with growth rate; (2) the apparent sink-driven modified Droop model predicts that structural biomass CUE decreases with growth rate; and (3) the sink-driven...

Warming and snow loss increase reliance on old groundwater in a Colorado River headwater

Tue, 21 Jul 2026 00:00:00 +0000

Atmospheric warming is reducing snowpack, with uncertain effects on mountainous streamflow, a crucial water resource. Despite limited historical observations of groundwater–streamflow interactions above 2,500 m, new measurements in the Upper Colorado River headwaters indicate declining groundwater storage that is dated decades to millennia old. Here we use integrated hydrologic modelling spanning water years 2015–2021 to determine whether the loss of old-age groundwater buffers streamflow during low-snow years and whether that loss is exacerbated with warming. Results show that old-groundwater contributions to streams remain relatively steady through time, unlike the more variable contributions from young groundwater. Numerical experiments of increased surface air temperatures (+2.5 °C and +4 °C) increase rain–snow fractions and evapotranspiration and decrease runoff ratio by 2–3% per degree Celsius increase. As streamflow declines with warming, the age of groundwater supporting...

A genome assembly of the speckled dace, Rhinichthys osculus

Thu, 16 Jul 2026 00:00:00 +0000

The speckled dace, Rhinichtyhs osculus, is a cyprinoid fish species complex (family: Leuciscidae) with one of the widest native ranges of any freshwater fish in western North America. It occupies a variety of freshwater habitats and exhibits considerable morphological and genetic variation across its range. Several endemic taxa within the species complex are imperiled, four of which are protected under the US Endangered Species Act, with two more proposed for listing. Here, we present an annotated, scaffold-level assembly of the speckled dace genome as part of the California Conservation Genomics Project (CCGP). Consistent with the CCGP genome assembly strategy, we used Pacific Biosciences HiFi long reads and Omni-C data for our de novo genome assembly and performed genome annotations on NCBI Eukaryotic Genome Annotation Pipeline using novel, species-specific RNA-Seq reads generated from five tissue types. The assembly consists of 490 scaffolds totaling approximately 1.15 Gb,...

The genome assemblies of the Tui chub, Siphateles bicolor, and Arroyo chub, Gila orcuttii

Thu, 16 Jul 2026 00:00:00 +0000

We present genome assemblies for two cyprinoid fishes, the tui chub (Siphateles bicolor) and the arroyo chub (Gila orcuttii). These fishes are ecologically important representatives of native fish assemblages in the western United States and are both species of conservation concern. The two species hybridize where introductions bring them into contact, with potentially important ecological and evolutionary implications that have not yet been thoroughly examined from a genomic perspective. We present de novo assemblies for both species, representing the first scaffold-level genomes within their respective genera, which were developed as part of the California Conservation Genomics Project using Pacific Biosciences HiFi and Omni-C data. Our tui chub assembly consists of 258 scaffolds spanning 1,148,084,093 base pairs, has a scaffold N50 of 45.9 mb, a contig N50 of 23.7 mb, and a BUSCO completeness score of 98.1%. Our arroyo chub assembly consists of 179 scaffolds spanning...

Decoupled carbon assimilation and growth responses to aridity in temperate deciduous oaks.

Mon, 22 Jun 2026 00:00:00 +0000

The magnitude of the terrestrial carbon sink remains a key uncertainty in future climate projections, in part due to poorly understood links between carbon uptake and its allocation to woody biomass in vegetation. Here, in this study, we show that photosynthesis and aboveground growth occur asynchronously across diel to seasonal scales in eight North American oak species. Across 137 tree ring sites, current-year annual growth was insensitive to climate variability after midsummer despite 26 to 36% of annual gross primary productivity (GPP) occurring during this period. Hourly GPP flux and growth measurements at four sites spanning seven site years further demonstrate that wood formation ceases earlier than photosynthesis and is restricted to periods of low atmospheric aridity and temperature. This photosynthesis-growth decoupling intensifies with interannual variability in vapor pressure deficit (r = 0.86, P < 0.05), suggesting that by assuming tight coupling...

Despite rapid warming, seed production is not leading poleward migration in North American and European forests

Fri, 5 Jun 2026 00:00:00 +0000

To survive climate change, forest trees will have to shift seed production poleward. However, warming will not stimulate tree fecundity in the north if it is limited by other habitat variables. We evaluated the responses of tree fecundity to climate change for 292 tree species in North America and Europe, using response velocity, defined as (climate sensitivity) × (climate-change rate). The sensitivities to climate were estimated for each species and combined with rates of climate change to quantify how temperature, moisture deficits, and late freeze are influencing biogeographic shifts in tree reproduction. The results show that moisture deficit and late freeze, not annual temperature, drive changing seed production. Unlike annual temperature, which is increasing generally, change in these climate variables is not driving poleward shifts in seed production. These findings do not challenge the expectation that forests might eventually shift poleward. Rather, they show why current...

Expert elicitation on agricultural enhanced weathering reveals carbon dioxide removal potential and uncertainties in loss pathways

Thu, 4 Jun 2026 00:00:00 +0000

Enhanced weathering in agriculture is a potential gigatonne-scale carbon dioxide removal (CDR) pathway, but its potential remains difficult to constrain. We used a formal expert elicitation process to estimate CDR potential and efficiency, uncertainties, and key data needs for six feedstocks. Expert opinion of global potential varied by feedstock, with estimates averaging 0.2-0.7 Gt CO2e/yr, but with a wide range (from a source to greater than 5 Gt CO2e/yr removal). When focusing on the American Midwest (pH 5.5-6), carbon dioxide removal efficiency, meaning the fraction of potential ultimately realized, ranged from 27-39%. Key uncertainties included feedstock availability, calcite saturation, and deep soil/freshwater emission pathways. There is a need for empirical data in key stages, with potential to leverage liming data where appropriate. Overall, there appears to be strong potential CDR at broad scales. However, continued research is necessary to build confidence when quantifying...

Decoupling economic growth from water use intensification

Thu, 4 Jun 2026 00:00:00 +0000

Economic growth typically requires an increase in natural resource extraction, energy production and waste accumulation, and is followed by a growing demand for commodities and services that leads to increasing pressure on nature. While the coupling between economic growth and environmental burdens has been widely investigated from the perspective of pollution, greenhouse gas emissions and climate warming, the relationship between economic development and human appropriation and use of water resources remains under-investigated. Here we examine the hydrologic impacts of growth through the lens of the food–energy–water nexus. We analyse major decoupling mechanisms associated with the spatial and temporal displacement of hydrologic impacts and technological efficiency. We highlight the limitations inherent to such mechanisms, as they achieve only local, temporary or relative decoupling, often by redirecting, but not reducing, the burden on water resources. We point out some promising...

Control of Vegetation and Temperature on Topsoil Water Losses

Wed, 6 May 2026 00:00:00 +0000

Abstract Due to its location at the interface between land surface and atmosphere, soil moisture (SM) plays an important role in modulating energy, water and carbon fluxes. During periods of decreasing SM, SM loss is dependent on evapotranspiration (ET), drainage and changes in plant water storage. Investigating SM loss can give important insights into these processes. Here we use 25 years of global remote sensing data to investigate how SM loss is controlled by vegetation and temperature. We find that positive vegetation anomalies lead to slower SM loss in most areas, except for cold boreal forests. We hypothesize that these effects arise from competing effects of soil shading, transpiration and root water uptake by the vegetation. The effect whereby positive vegetation anomalies increase SM loss is limited to high SM conditions and disappears at lower SM, likely due to water stress limiting transpiration. By analyzing temperature and vegetation anomalies jointly we find...

Impacts of warming on outdoor worker well-being in the tropics and adaptation options

Wed, 6 May 2026 00:00:00 +0000

Over a billion outdoor workers live in the tropics, where nearly a fifth of all hours in the year are hot and humid enough to exceed recommended safety thresholds for workers conducting heavy labor. Reviews have focused on heat impacts on worker health, well-being, and productivity, but synthesis on how to increase resilience to heat for outdoor workers is lacking. Here we assess current and future heat exposure in the tropics and review four bodies of literature on heat impacts on workers. We also synthesize knowledge about mitigation and adaptation uncertainties as well as the actions that can be taken to strengthen worker resilience. We show that under an additional 1°C of warming, ∼800 million people in the tropics will live in areas where heavy work should be limited for over half of the hours in the year. Our review provides primary, secondary, and tertiary solutions that will inform policies and practices as well as research that is needed to bolster worker resilience and...

Comprehensive review of carbon quantification by improved forest management offset protocols

Mon, 27 Apr 2026 00:00:00 +0000

Comprehensive review of carbon quantification by improved forest management offset protocols

Soil Moisture Buffers the Impact of Precipitation Variability on Ecosystem Productivity

Thu, 23 Apr 2026 00:00:00 +0000

Abstract Water availability governs ecosystem productivity, yet estimates of vegetation sensitivity to water can differ greatly depending on whether the sensitivity is examined spatially or temporally. In particular, the spatial sensitivity is often reported to be much stronger than temporal sensitivities, leading to highly uncertain projections of ecosystem responses to future climate change when using space‐for‐time substitution. The large difference between spatial and temporal sensitivities remains unexplained. Prior research, however, primarily relied on precipitation as the water availability proxy, whereas vegetation responds to soil moisture. Here, we combined satellite estimates of vegetation productivity with soil moisture data across water‐limited ecosystems of the continental United States (CONUS) to identify a convergent sensitivity of productivity to water availability. Using precipitation, we show that temporal sensitivity is 66% lower than spatial sensitivity overall....

Cannabis Bans, Local Control, and the Effects and Efficacy of Proposition 64

Thu, 23 Apr 2026 00:00:00 +0000

Cannabis Bans, Local Control, and the Effects and Efficacy of Proposition 64

Bioenergy Cropping Reduces the Spatiotemporal Scaling of Soil Bacterial Biodiversity

Thu, 23 Apr 2026 00:00:00 +0000

Widespread bioenergy cropping can transform landscapes, strongly affecting biodiversity. However, the impact of bioenergy cropping on the spatiotemporal scaling of soil biodiversity remains virtually unknown, despite its profound implications for the functioning of the ecological community. Here, we investigated how bioenergy cropping influenced the spatiotemporal scaling of soil bacterial biodiversity in marginal soils (sandy loam and clay loam soils) in Oklahoma, USA. We detected strong, significant species-time-area relationships (STARs) and phylogenetic-time-area relationships (PTARs) in bacterial communities and their lineages, suggesting that STARs and PTARs exist in microbial ecology within the studied system. Also, spatiotemporal scaling rates (the slopes of STAR and PTAR models) varied substantially among bacterial lineages and were positively correlated with their 16S rRNA gene copy numbers, a genomic trait indicative of microbial growth potentials. Strikingly, bioenergy...

Planning for marijuana: Development, governance and regional political economy

Sat, 11 Apr 2026 00:00:00 +0000

The chapter, which is based upon 19 months of fieldwork and numerous interviews of variously positioned informants across the legal/illegal spectrum, first situates this study within examinations of extraction-based regional political economies,4 attending to the uneven development of governing capacities in these regions. Then it traces the growth of Humboldt’s timber developmental regime, its articulation with marijuana prohibition, and, following timber’s industrial decline, the struggle that emerged among environmentalists and rentier capitalists to guide the development of marijuana and the county’s broader political economy.

Property, capitalism, and the value‐shaping power of states

Sat, 11 Apr 2026 00:00:00 +0000

Property, capitalism, and the value‐shaping power of states

Cultivating Cannabis, Excepting Cannabis

Sat, 11 Apr 2026 00:00:00 +0000

Cultivating Cannabis, Excepting Cannabis

Marketing Marijuana: Prohibition, Medicalization and the Commodity

Sat, 11 Apr 2026 00:00:00 +0000

US marijuana legalization breaks with prohibition in many ways. Despite celebrations of the “green rush” and market “emergence,” however, marijuana’s formation as a market has a longer history rooted in prohibition. Drawing from ethnographic research, this chapter argues that an expanded War on Drugs in the 1980s produced a field of intervention, “the marijuana economy,” that incited marketized subjectivities, discourses and practices in a neoliberal, if paradoxically illiberal, manner. Later, marijuana’s not-for-profit medicalization was also made legible in market terms. As marijuana enters formal market circulation, this chapter urges attention to its articulation with older market moralities and inequalities.

Assessing land use change trajectories following food insecurity shocks in 25 low- and middle-income countries

Thu, 9 Apr 2026 00:00:00 +0000

Food insecurity is a perennial problem in much of the developing world, with gains against hunger backsliding in recent years and climate change predicted to accelerate this trend. Food insecurity is highly disruptive to rural livelihoods and can lead to dramatic shifts in food production strategies and resultant land use. However, studies to date have yet to outline the overarching patterns of land use change that can result from food insecurity. We elucidate the impact of food insecurity events between 2013 and 2020 in 25 low- and middle-income countries on resulting land use change and demographics. Using propensity score matching, we create a counterfactual and assess changes in forest cover, crop cover, population and nighttime luminosity between regions that experience food insecurity and comparable food-secure regions. Land use change theory, specifically the classical trajectories of agricultural intensification, land rent theory, and regime shifts help to explain observed...

Modeling the Risk Reduction Benefit of Forest Management Using a Case Study in the Lake Tahoe Basin

Thu, 9 Apr 2026 00:00:00 +0000

Across the United States, wildfire severity and frequency are increasing, placing many properties at risk of harm or destruction. We quantify and compare how different forest management strategies designed to increase forest resilience and health reduce the number of properties at risk from wildfire, focusing on the Lake Tahoe Basin of California and Nevada. We combine landscape change simulations (including climate change, wildfire, and management effects) with scenarios of current and plausible fuel treatment activities and parcel-scale fire risk analysis. Results suggest that more aggressive fuel treatment activities that treat more area on the landscape, whether through mechanical and hand thinning or prescribed fire, dramatically lower the fire probability in the region and lead to a corresponding lower risk of property loss. We estimate that relative to recent practices of focusing management in the wildland–urban interface, more active forest management can reduce property...

Using payment for ecosystem services to meet national reforestation commitments: impacts of 20+ years of forestry incentives in Guatemala

Thu, 9 Apr 2026 00:00:00 +0000

International environmental initiatives, such as the Bonn Challenge and the UN Decade on Restoration, have prompted countries to put the management and restoration of forest landscapes at the center of their land use and climate policies. To support these goals, many governments are promoting forest landscape restoration and management through financial forestry incentives, a form of payment for ecosystem services. Since 1996, Guatemala has implemented a series of forestry incentives that promote active forest landscape restoration and management on private and communal lands. These programs have been widely hailed as a success with nearly 600 000 ha enrolled since 1998. However, there has been no systematic assessment of the effectiveness of these programs on preserving and restoring Guatemalan forests. This study evaluates the impacts of over 16 000 individual PES projects funded through two incentive programs using a synthetic control counterfactual. Overall, a program for...

Social-ecological drought and smallholder vulnerability in the Central American Dry Corridor

Thu, 9 Apr 2026 00:00:00 +0000

Impacts from droughts are of heightened concern in smallholder-dominated areas globally, with climate change projected to drive increasing frequency and severity of droughts in the coming decades. Zacapa Department, Guatemala, has seen dramatic effects of El Niño-driven seasonal drought on smallholder agricultural systems, with reports of up to 80% crop losses in recent years. We assess vulnerability and drought impacts in these systems by integrating an ethnographic analysis of smallholders’ experiences of climate change in two adjacent communities in Zacapa with remotely sensed data on plant greenness anomaly and water deficit. Although recent droughts were not historically anomalous, we found increases in growing-season water deficit, which were particularly impactful to livelihoods and vegetation health. Farmers perceive recent droughts as more frequent and harmful than historic events and provide proximate and religious explanations for these changes, such as attributing...

Trait‐based approaches to restoration ecology: Synthesizing insights from diverse systems

Wed, 25 Mar 2026 00:00:00 +0000

Under accelerating global change, trait-based approaches are emerging as essential tools in the ecological restoration toolbox. Where restoration has traditionally focused on the recovery of focal species in isolated systems, trait-based methods can provide a common language that extends beyond species- or system-specific contexts, allowing scientists and practitioners to translate insights across organisms and ecosystems and predict functional variation critical to resilience in the face of rapidly changing environmental conditions. Trait-based insights can thus help achieve restoration that is both adaptable and scalable as future climate scenarios unfold. To date, trait-based approaches to restoration have developed and proceeded independently across habitats and ecosystems, limiting information sharing and innovation. Here, we synthesize diverse perspectives and research on trait-informed restoration across ecosystems, distilling our findings into three key insights. First,...

Observed declines in leaf nitrogen explained by photosynthetic acclimation to CO2

Thu, 12 Mar 2026 00:00:00 +0000

Widespread evidence of decreasing leaf nutrients has raised concerns about ecosystem productivity under global change. Interpreting trends in leaf nutrients has important implications for the fate of ecosystem services, particularly the role of forests in mitigating climate change and sustaining quality food sources. Here, we challenge the common interpretation that decreasing leaf nitrogen concentration (LNC) is evidence of increasing nutrient limitations on ecosystem primary productivity. Instead, we show that declines in LNC (4% decrease per 50 ppm CO₂ increase), observed across 409 European forest plots over 22 y, can be explained by reduced photosynthetic nitrogen demand. This regional trend is consistent with leaf acclimation to increasing atmospheric CO₂ according to optimality theory. This finding suggests that enhanced photosynthetic nitrogen use efficiency due to CO₂ fertilization may lead to less nitrogen uptake...

Land-based resources for engineered carbon dioxide removal in the United States exceed the expected needs

Fri, 6 Mar 2026 00:00:00 +0000

Gigatonne-scale atmospheric carbon dioxide removal (CDR), alongside deep emission cuts, is critical to stabilizing the climate. However, some of the most scalable CDR technologies are also the most land intensive. Here, we examine whether adequate land resources exist in the contiguous United States to meet CDR targets when prioritizing grid emissions reduction, food production, and the protection of sensitive ecosystems. We focus on biomass carbon removal and storage (BiCRS) and direct air capture and storage (DACS) and show that suitable lands exceed the expected needs: 37.6 million hectares of land are available for BiCRS, resulting in 0.26 GtCO2 of CDR/year, and 34 million hectares are suitable for wind- and solar-powered DACS, resulting in 4.8 GtCO2 of CDR/year if facilities are co-located with geologic CO2 storage. We identify biomass and energy supply hotspots to meet CDR targets while ensuring land protection and minimizing land competition.

Land use and mineral type determine stability of newly formed mineral-associated organic matter

Thu, 12 Feb 2026 00:00:00 +0000

Formation of mineral-associated organic matter (MAOM) is a key process in the global carbon cycle, stabilising organic carbon in soils. The relative importance of mineral composition and land use as potential controls of MAOM stability at regional scales and underlying microbial processes are still unresolved. Here, we assessed the stability of MAOM formed on goethite (iron oxide) and illite (phyllosilicate clay) exposed for five years in topsoils at 68 forest and grassland sites across Germany. We incubated the newly formed MAOM, determined its extractability, and analysed the composition and functioning of associated microbial communities. Decomposition of MAOM was always significantly lower for goethite than illite, highlighting that higher organic carbon accumulation on goethite was not exclusively due to its larger sorption capacity. Instead, reduced organic carbon extractability and higher phosphorus-acquiring enzyme activities indicated stronger substrate limitation of...

Future implications of enhanced hydroclimate variability and reduced snowpack on California’s water resources

Tue, 27 Jan 2026 00:00:00 +0000

The Sierra Nevada snowpack, which supplies sixty percent of California’s consumptive water use, is under threat due to anthropogenic climate change. While previous studies have examined the impacts of climate change on mountain snowpack in the Sierra Nevada and across the Western US, few have quantified the risks to monthly irrigation water resources posed by shifting hydroclimate patterns and declining snowmelt runoff. Because they use coarse-resolution models, existing global-scale studies lack regional specificity, while existing regional studies rely on statistical or dynamical ‘downscaling’ of coarse-resolution global models. We use a new simulation of the variable resolution Community Earth System Model 2, which provides high spatiotemporal resolution estimates (14 km horizontal grid spacing, daily-to-hourly outputs) of California’s historical and future hydroclimate. We leverage the US Geological Survey’s recent irrigation water use reanalysis to evaluate basin-scale irrigation...

Multi-omics reveals nitrogen dynamics associated with soil microbial blooms during snowmelt

Tue, 27 Jan 2026 00:00:00 +0000

Snowmelt triggers a soil microbial bloom and crash that affects nitrogen (N) export in high-elevation watersheds. The mechanisms underlying these microbial dynamics are uncertain, making soil nitrogen processes difficult to predict as snowpack declines globally. Here, integration of genome-resolved metagenomics, metatranscriptomics and metabolomics in a high-elevation watershed revealed ecologically distinct soil microorganisms linked across the snowmelt time-period by their unique nitrogen cycling capacities. The molecular properties and transformations of dissolved organic N suggested that degradation or recycling of microbial biomass provided N for biosynthesis during the microbial bloom. Winter-adapted Bradyrhizobia spp. oxidized amino acids anaerobically and had the highest gene expression for denitrification during the microbial bloom. A pulse of nitrate was driven by spring-adapted Nitrososphaerales after snowmelt, but dissimilatory nitrate reduction to ammonia (DNRA) gene...

Crop diversification improves water-use efficiency and regional water sustainability

Wed, 21 Jan 2026 00:00:00 +0000

As global water scarcity intensifies, identifying agricultural practices that enhance sustainable water management is critical. Temporal crop diversification-rotating multiple species over time-has been proposed to improve soil health and water retention based on field-scale experiments. However, widespread adoption remains limited on farms, in part due to unverified benefits at larger scales. Here, we assess the influence of crop diversification on agricultural water-use efficiency (WUE, ratio of gross primary productivity to evapotranspiration) along a spectrum of monoculture to complex species rotations in California. Leveraging new high-resolution remote sensing datasets, we show that crop diversification is a key driver of agricultural WUE, and increasing the number of species planted in the previous 6 years from two to four increases WUE by ∼20% after accounting for differences between crops. Our results provide spatially explicit, large-scale quantification of crop diversification’s...

Accounting for herbaceous communities in process‐based models will advance our understanding of “grassy” ecosystems

Mon, 5 Jan 2026 00:00:00 +0000

Grassland and other herbaceous communities cover significant portions of Earth's terrestrial surface and provide many critical services, such as carbon sequestration, wildlife habitat, and food production. Forecasts of global change impacts on these services will require predictive tools, such as process-based dynamic vegetation models. Yet, model representation of herbaceous communities and ecosystems lags substantially behind that of tree communities and forests. The limited representation of herbaceous communities within models arises from two important knowledge gaps: first, our empirical understanding of the principles governing herbaceous vegetation dynamics is either incomplete or does not provide mechanistic information necessary to drive herbaceous community processes with models; second, current model structure and parameterization of grass and other herbaceous plant functional types limits the ability of models to predict outcomes of competition and growth for herbaceous...

Speciation Genomics in the Tiger Whiptail Lizards (Aspidoscelis tigris Complex)

Thu, 25 Dec 2025 00:00:00 +0000

The transition from small genetic to genome-scale datasets for studying biodiversity has revealed that genetic exchange through introgressive hybridization is a widespread phenomenon in nature. Despite this, a lack of high-quality reference genomes for most non-model species limits our understanding of the impact of this process for many taxonomic groups. This restricts the range of insights that genomic tools can provide for conservation biologists, who often hope to employ genomic datasets to accurately identify historically isolated lineages to protect and to predict their evolutionary fate in the face of environmental change. Tiger whiptail lizards (Aspidoscelis tigris complex) are an abundant and important ecological component of ecosystems across the southwestern United States. In this study, we assembled and annotated a chromosome-level reference genome for A. t. stejnegeri from coastal California. We then used this reference genome to reconstruct patterns of speciation...

Human-wildlife conflict is amplified during periods of drought

Mon, 24 Nov 2025 00:00:00 +0000

Climate change-induced alterations to human-wildlife interactions are recognized to pose a fundamental challenge for global conservation initiatives. However, the extent to which specific climatic disturbances influence dynamics of human-wildlife conflict across different taxonomic groups remains poorly understood. Here, we leverage an extensive dataset of community-derived human-wildlife conflict incidents to examine the influence of drought, represented by the variation in summed precipitation over the prior 12 months, on conflict reporting. We show that prolonged decreases in precipitation are associated with increased overall conflict occurrences across taxa and are significantly associated with increased conflict with carnivore species in particular. A future with increasingly severe and frequent droughts could lead to resource scarcity that not only causes conflict between humans but also between humans and the natural world around them.

Phenology‐informed decline risk of estuarine fishes and their prey suggests potential for future trophic mismatches

Wed, 19 Nov 2025 00:00:00 +0000

Conservation scientists have long used population viability analysis (PVA) on species count data to quantify critical decline risk, thereby informing conservation actions. These assessments typically focus on a single species rather than assemblages and assume that risk is consistent within a given life stage (e.g., across the different seasons or months of a year). However, assessing risk at overly broad temporal or spatial scales may obscure diverging population declines between predators and prey, potentially disrupting biotic interactions. In this study, we used time-series-based PVA for age-0 forage fishes and their potential zooplankton prey for each month of the year in the San Francisco Estuary, over 1995-2023 (N = 175 time series). The PVA were parameterized using Multivariate Autoregressive (MAR) models that estimate long-term population trends and variability (i.e., process error) for each population. We found widespread negative population trends across fish species...

Carbon costs of different pathways for reducing fire hazard in the Sierra Nevada

Wed, 19 Nov 2025 00:00:00 +0000

Restoring a low-intensity, frequent-fire regime in fire-prone forests offers a promising natural climate solution. Management interventions that include prescribed fire and/or mechanical treatments have effectively reduced fire hazards in the Western United States, yet concerns remain regarding their impact on forest carbon storage. This study used results from a long-term, replicated field experiment to assess the impacts of a restored disturbance regime on carbon dynamics in a Sierra Nevada, mixed conifer forest. The carbon consequences of the treatments were compared to a dynamic baseline of untreated controls (Control). After 19 years of wildfire mitigation, all treated stands stored less carbon than Control, but a larger proportion was sequestered in wildfire-resistant pools (i.e., large trees or fire-resistant species). Notably, only the most intensive treatment regime-thinning, mastication, and prescribed fire (Mech+Fire)-became a net carbon source by Year 20 (-60 MgC/ha)....

Ocean-influenced estuarine habitat buffers high interannual variation in seabird reproductive success

Wed, 5 Nov 2025 00:00:00 +0000

Seabirds in more variable habitats generally live longer and more readily forgo or reduce breeding investments in poor resource seasons to maximize their overall lifetime fitness. Their breeding success is dependent on factors including diet, prey availability, and proximity to foraging habitat. Furthermore, seabird colonies in upwelling ecosystems are subject to interannual variation in oceanic conditions that drive bottom-up processes. Adjacent estuarine ecosystems, while less affected by upwelling, are also influenced by freshwater input and may experience less interannual variation in seabird prey resources. Here, we compare the breeding ecology and diet of pigeon guillemots Cepphus columba from an estuarine colony (Alcatraz Island, California) and an isolated offshore colony (Southeast Farallon Island, California) from 2015 to 2017 to understand how habitat location and surrounding environment differentially influence diet and reproduction....

Modeling coupled dynamics of an empirical predator-prey system to predict top predator recovery

Wed, 5 Nov 2025 00:00:00 +0000

Limited data, time, and funding lead conservation managers to make difficult choices in managing species recovery. Coupled dynamical models are relied upon for decision support, but their application to empirical predator-prey systems has generally been restricted to small, tractable species. To broaden their use in conservation decision-making, we developed a model suitable for predicting the population dynamics of a larger apex carnivore and its prey. We selected southern sea otters (Enhydra lutris nereis) and their primary estuarine prey as our case study and parameterized the dynamical model with data on sea otter, clam, and crab abundances; predator-prey interactions; and sea otter bioenergetics collected from Elkhorn Slough, CA. Our model, having integrated all these salient factors, was able to successfully reproduce trends in taxa abundance as well as shifts in sea otter diet composition and energy intake rates. Rich data inputs allow the model to predict population dynamics...

Synthetic Scientific Image Generation with VAE, GAN, and Diffusion Model Architectures

Tue, 23 Sep 2025 00:00:00 +0000

Generative AI (genAI) has emerged as a powerful tool for synthesizing diverse and complex image data, offering new possibilities for scientific imaging applications. This review presents a comprehensive comparative analysis of leading generative architectures, ranging from Variational Autoencoders (VAEs) to Generative Adversarial Networks (GANs) on through to Diffusion Models, in the context of scientific image synthesis. We examine each model's foundational principles, recent architectural advancements, and practical trade-offs. Our evaluation, conducted on domain-specific datasets including microCT scans of rocks and composite fibers, as well as high-resolution images of plant roots, integrates both quantitative metrics (SSIM, LPIPS, FID, CLIPScore) and expert-driven qualitative assessments. Results show that GANs, particularly StyleGAN, produce images with high perceptual quality and structural coherence. Diffusion-based models for inpainting and image variation, such as DALL-E...

Methanogenesis and Acetogenesis in Hydrogenotrophy with Carbonate Minerals: Dependence on Mineral Surface Area, Biofilm Growth, and Microbial Community

Mon, 8 Sep 2025 00:00:00 +0000

The production, storage, and use of hydrogen are anticipated to grow substantially to achieve energy and climate goals. Consequently, microbial communities in many terrestrial and subsurface Earth environments could be exposed to elevated hydrogen concentrations. Hydrogen stimulates metabolic processes that reduce aqueous chemical species, such as bicarbonate or sulfate, that can exchange with solid mineral phases, but the controls on microbial hydrogenotrophy with mineral sources of electron acceptors are not fully understood. Herein, we applied laboratory experiments and biogeochemical modeling to study the response of a natural microbial community to an elevated partial pressure of hydrogen in the presence of carbonate minerals of varying composition, solubility, and size. Experimental incubations and simulation results showed that hydrogen consumption by microbial communities was initially dominated by sulfate reduction and, subsequently, transitioned to acetogenesis and methanogenesis....

Widespread and complex drought effects on vegetation physiology inferred from space

Fri, 29 Aug 2025 00:00:00 +0000

The response of vegetation physiology to drought at large spatial scales is poorly understood due to a lack of direct observations. Here, we study vegetation drought responses related to photosynthesis, evaporation, and vegetation water content using remotely sensed data, and we isolate physiological responses using a machine learning technique. We find that vegetation functional decreases are largely driven by the downregulation of vegetation physiology such as stomatal conductance and light use efficiency, with the strongest downregulation in water-limited regions. Vegetation physiological decreases in wet regions also result in a discrepancy between functional and structural changes under severe drought. We find similar patterns of physiological drought response using simulations from a soil–plant–atmosphere continuum model coupled with a radiative transfer model. Observation-derived vegetation physiological responses to drought across space are mainly controlled...

Meeting the EAT-Lancet ‘healthy’ diet target while protecting land and water resources

Thu, 28 Aug 2025 00:00:00 +0000

Meeting the EAT-Lancet ‘healthy’ diet target while protecting land and water resources

Land Use Change and Infectious Disease Emergence

Thu, 28 Aug 2025 00:00:00 +0000

Abstract: Major infectious diseases threatening human health are transmitted to people from animals or by arthropod vectors such as insects. In recent decades, disease outbreaks have become more common, especially in tropical regions, including new and emerging infections that were previously undetected or unknown. Even though there is growing awareness that altering natural habitats can lead to disease outbreaks, the link between land use change and emerging diseases is still often overlooked and poorly understood. Land use change typically destroys natural habitat and alters landscape composition and configuration, thus altering wildlife population dynamics, including those of pathogen hosts, domesticated (often intermediary) hosts, infectious agents, and their vectors. Moreover, land use changes provide opportunities for human exposure to direct contact with wildlife, livestock, and disease‐carrying vectors, thereby increasing pathogen spillover from animals to humans. Here...

Connecting inequalities in land ownership and groundwater access: the case of California’s Central Valley

Thu, 28 Aug 2025 00:00:00 +0000

Understanding inequality in groundwater access and cropland ownership is critical for assessing the sustainability and equity of agricultural systems, especially in regions facing climatic and socioeconomic patterns such as drought and cropland consolidation. These two forms of access are deeply interconnected: for instance, cropland ownership often determines who can access and control groundwater. Due to data challenges, however, few studies have quantified groundwater access inequality in the same ways that land ownership has been quantified. Similarly, the regional scale of most analyses to date limits our understanding of factors that shape and modify these interconnections. Our study aims to address this gap by constructing a novel geospatial dataset by matching groundwater wells with cropland parcels across California’s Central Valley. We quantify the magnitude and spatial patterns of groundwater and cropland inequality and examine how it scales with land ownership, crop...

Modelling co-evolution of resource feedback and social network dynamics in human-environmental systems

Thu, 28 Aug 2025 00:00:00 +0000

Abstract: Games with environmental feedback have become a crucial area of study across various scientific domains, modelling the dynamic interplay between human decisions and environmental changes, and highlighting the consequences of our choices on natural resources and biodiversity. In this work, we propose a co-evolutionary model for human-environment systems that incorporates the effects of knowledge feedback and social interaction on the sustainability of common pool resources (CPRs). The model represents consumers as agents who adjust their resource extraction based on the resource’s state. These agents are connected through social networks, where links symbolize either affinity or aversion among them. The interplay between social dynamics and resource dynamics is explored, with the system’s evolution analyzed across various network topologies and initial conditions. We find that knowledge feedback can independently sustain CPRs. However, the impact of social...

Global variation in vegetation carbon use efficiency inferred from eddy covariance observations

Thu, 28 Aug 2025 00:00:00 +0000

Terrestrial ecosystems have been serving as a strong carbon sink that offsets one-quarter of anthropogenic CO2 emissions. Carbon use efficiency (CUE), the percentage of photosynthesized carbon that is available for biomass production and other secondary carbon products, is one factor determining the carbon sink size. The global variation in CUE remains unclear, however, as recent reports disagree over the responses of CUE to temperature, dryness, forest types and stand age, and there are limited direct observations to constrain the related uncertainty. Here, we propose to infer CUE from spatially distributed observations of land–atmosphere CO2 exchange from global eddy covariance sites based on the degree of ecosystem respiration–photosynthesis coupling. Across 2,737 site-years, CUE derived from eddy covariance observations is 0.43 ± 0.12, consistent with previous inventory-based estimates (0.47 ± 0.12, n = 301) but with a better representation of spatial–temporal variation in...

The role of the Allee effect in common pool resource games with environmental feedback

Thu, 28 Aug 2025 00:00:00 +0000

The role of the Allee effect in common pool resource games with environmental feedback

Widespread underestimation of rain-induced soil carbon emissions from global drylands

Thu, 28 Aug 2025 00:00:00 +0000

Dryland carbon fluxes, particularly those driven by ecosystem respiration, are highly sensitive to water availability and rain pulses. However, the magnitude of rain-induced carbon emissions remains unclear globally. Here we quantify the impact of rain-pulse events on the carbon balance of global drylands and characterize their spatiotemporal controls. Using eddy-covariance observations of carbon, water and energy fluxes from 34 dryland sites worldwide, we produce an inventory of over 1,800 manually identified rain-induced CO2 pulse events. Based on this inventory, a machine learning algorithm is developed to automatically detect rain-induced CO2 pulse events. Our findings show that existing partitioning methods underestimate ecosystem respiration and photosynthesis by up to 30% during rain-pulse events, which annually contribute 16.9 ± 2.8% of ecosystem respiration and 9.6 ± 2.2% of net ecosystem productivity. We show that the carbon loss intensity correlates most strongly with...

¿Libre de la Maleza Estatista? Assessing Neoliberal Promises and Water Markets in Chile

Thu, 28 Aug 2025 00:00:00 +0000

Abstract: Neoliberal approaches to water governance, pioneered in Chile in the 1980s, are reappearing today on the centerstage of the water policy debate. While advocates claim that strong property rights, limits on government authority, and water markets can enhance environmental sustainability, efficiency, neutrality, and equity in the distribution of water rights, limited empirical evidence exists on whether neoliberal policies have delivered on these key promises. In this paper, we combine hydrological analysis with a nationwide data set on government water rights allocations between 1981 and 2021 to determine when and where water has been allocated beyond sustainable limits. We then integrate water market transaction and agricultural data to assess how allocations and scarcity conditions relate to spatial and temporal patterns in irrigation, crop distribution, and water market activity. Our results indicate that 30% of catchments are overallocated, and that continued government...

Appropriation pathways of water grabbing

Thu, 28 Aug 2025 00:00:00 +0000

Appropriation pathways of water grabbing

Seasonal stabilization effects slowed the greening of the Northern Hemisphere over the last two decades

Thu, 14 Aug 2025 00:00:00 +0000

Rising atmospheric CO₂ and warming spring temperatures increase vegetation growth and the terrestrial carbon sink. However, drought, heat stress, phenology, and resource limitations may stabilize or limit theses projected increases. We investigate the balance between these amplifying and stabilizing ecological factors by asking whether enhanced early-season growth leads to continued late-season growth. Using the Moderate Resolution Imaging Spectroradiometer (MODIS) leaf area index (LAI) dataset, we identify three seasonal growth patterns based on early- and peak-season positive LAI anomalies: (1) amplification, where late-season LAI anomalies exceed earlier ones; (2) weak stabilization, where late-season anomalies remain similar or slightly lower; and (3) strong stabilization, where late-season anomalies become negative. Weak and strong stabilization events dominate across 67% and 26% of Northern Hemisphere ecosystems above 30°N, respectively. The absence of any trend in amplifying...

Consumer feces impact coral health in guild-specific ways