Climate Change Scenarios Research Articles

Catchment-based water resources modelling and planning of the transboundary Inkisi River in the Congo Basin

ABSTRACT Large river basins exhibit many local-scale management concerns for which a catchment-based approach is required. This study addresses the need for hydrological and water resources management information at the scale of decision making, the catchment scale. A hydrology and water resources planning modelling approach is applied to a transboundary Inkisi River in the Congo basin, based on six catchments that were partitioned following the catchment classification framework for Congo basin. The model is established for the reference period, spanning from 1948 to 2021, to generate the necessary information on water availability, and is used to assess future scenarios of climate change and water demands for the horizon 2100. The model is calibrated using on 20 years of available streamflow data, which shows a good performance based on the objective functions of hydrological model evaluation. Assessment of the impact of climate change, based on two emissions scenarios, RCP4.5 and RCP 8.5, shows a decreasing trend in water availability, highlighting the need for adaptive water management strategies.

Beyond the Trail—Understanding Non‐Native Plant Invasions in Mountain Ecosystems

ABSTRACTAimWe aimed to examine the abiotic, biotic and anthropogenic drivers of non‐native plant species distribution along hiking trails in mountainous regions.LocationNine mountain regions across six continents, including North America (USA), South America (Argentina and Chile), Europe (Sweden, Norway, Czech Republic), Africa (South Africa), Asia (China) and Oceania (Australia).Time PeriodData were collected between 2016 to 2022 during the summer season.Major Taxa StudiedVascular plants.MethodsWe implemented a standardised sampling design (MIREN trail survey) with T‐shaped sample sites placed parallel to trails and perpendicular to adjacent vegetation. We examined the main drivers (abiotic, biotic and anthropogenic factors) affecting non‐native species' presence, richness and cover.ResultsAt the global scale, abiotic (climatic) variables explained most of the variation in non‐native species richness. In contrast, biotic factors were the most important for the presence and cover of non‐native plants. Anthropogenic factors, including distance to the trail, use intensity and livestock grazing, were also important but to a lesser extent than the main factors. While the total number of non‐native species differed across regions, the patterns explaining plant invasions were consistent.Main ConclusionsOur regional study identified mountain trails that are particularly vulnerable to plant invasions. Our findings suggest that under future scenarios of climate change, increased anthropogenic pressure and heightened livestock activity, the presence of non‐native species beyond trail edges may become more frequent. This highlights the need to restrict off‐trail activities in areas of high conservation value.

INCORPORATING CLIMATE CHANGE INTO COASTAL COMPOUND FLOOD RISK

Coastal communities are increasingly vulnerable to multi- hazard events such as storm surges, riverine flooding, and precipitation-induced runoff. Current engineering practices and risk management strategies necessitate a comprehensive assessment of these concurrent risks to effectively mitigate potential damages. Traditional methods, including those outlined in the North Atlantic Coast Comprehensive Study (NACCS) by the US Army Corps of Engineers (USACE, 2015), tend to focus on storm surge and wave contributions on coastal flooding, and less so combined effects of precipitation. Advancements in climate science suggest a shifting baseline for the frequency and intensity of these events under climate change scenarios, although associated with uncertainties. Despite these uncertainties, there is a need for tools that integrate predicted climate change impacts into coastal flooding hazard evaluations, thereby enhancing the alignment of engineering practices with applied climate and weather research. This presentation introduces a framework for evaluating coastal flood risks incorporating the effects of climate change.

EXPLORING THE VIABILITY OF ACCOMMODATION SPACE-BASED COASTAL ADAPTATION IN DEVELOPED MEDITERRANEAN COASTS

At present, a substantial part of the Mediterranean sedimentary coastline is retreating (e.g. Luijendijk et al. 2018), a trend that could be intensified by climate change, thereby increasing the risk of beach disappearance (e.g. Vousdoukas et al. 2020). Harnessing the natural resilience of coastal ecosystems to adapt to external pressures is gaining prominence as a favored approach for enhancing climate resilience and thus support EU policy priorities. This work presents a framework for assessing the necessary accommodation space to facilitate the natural rebuilding of beaches under an external forcing. It integrates predictions of the space requirement to cope with coastal hazards under both current and future climate change scenarios, within relevant time horizons for planning purposes. The ultimate practical goal is to categorize the territory based on space requirements, land characteristics, and the feasibility of generating the necessary space. This classification will also enable the identification of areas suitable for the implementation of adaptation measures that demand additional space, such as dunes, wetlands or managed retreat, differentiating between those where such measures can be easily applied and areas where they are only viable for short-term horizons.

MODELING THE FUTURE OF CORAL REEFS: AN ECO-MORPHODYNAMIC APPROACH

Coral reefs are complex biological structures that provide critical ecosystem services, such as provision of habitat for marine organisms, fisheries supply, recreational space for tourism industry, and coastal protection. Due to climate change, coral reefs have been undergoing, and will continue to experience, alterations in their capacity to deliver essential ecosystem services. To comprehend these existing alterations and forecast reef responses to future climate change scenarios, it is imperative to employ dynamic modeling approaches that encompass both abiotic and biotic factors. This study aims to build an eco-morphodynamic point model (also known as a Zero-Dimensional – 0D - Model) that incorporates the key variables responsible for driving changes within reef systems, ultimately affecting their capacity to mitigate wave impacts and facilitate sediment production. For the development of this model, we chose the Great Barrier Reef (GBR) as a testing ground, due to its extensive reef network, offering a wide range of scenarios, and its ample and long-term data availability.

NATIONAL ASSESSMENT OF SEA LEVEL RISE VULNERABILITY OF ARCHEOLOGICAL HERITAGE SITES OF TURKIYE

The coastal cultural heritage sites are expected to be affected negatively by sea-level rise, although these impacts will be observed at different levels in different areas. ICOMOS (2019) has urged the member states to determine and assess the vulnerability and risks of those cultural heritage sites that are under threat and increase the efforts to protect and adapt these locations to the impacts of climate change. Turkey has many significant natural and archeological heritage sites with outstanding values, and these areas are protected by law. The Scientific and Technological Research Council of Turkiye (TUBITAK) funded project “Vulnerability of Coastal Cultural Heritage Areas to Sea Level Rise and Its Impacts” (No: 122M613) focused on assessing the vulnerability of the coastal areas with heritage sites (both natural and cultural sites protected by law) to sea level rise and its impacts (coastal erosion, inundation and coastal flooding due to extreme water levels) using the Fuzzy Coastal Vulnerability Assessment Model, FCVAM (Ozyurt, 2010). Within the project, an additional module is developed to determine the vulnerability of coastal cultural heritage sites based on their interaction with the coastal area and the coastal vulnerability. The assessments use several sea level rise projections based on different climate change scenarios to ensure that the vulnerability of these sites reflects the latest sea level rise research and the uncertainty ranges. Thus, the coastal cultural heritage sites of Turkiye will be prioritized according to their vulnerability at a national level and using a multi-dimensional approach. This study will present these Turkish coastal archeological heritage sites exposed to impacts of sea level rise, their respective coastal vulnerability indices, and the heritage vulnerability results based on the heritage site characteristics and their interaction with the coastal vulnerability.

Co-constructing and simulating LUCC scenarios for evaluating the sustainability of environmental policies and supporting long-term decision-making

Urbanization and agricultural intensification are major drivers of biodiversity loss due to multiple stressors, including land artificialization, habitat fragmentation, isolation, and degradation. These land-use and land-cover changes (LUCC) also impact water quality, carbon sequestration, and ecosystem services. Designing Blue and Green Infrastructure Networks (BGINs) has been proposed as a strategic approach to land-use planning that enhances ecosystem services while preserving biodiversity and improving water management. This study focuses on the Couesnon watershed (Brittany, France) within the LTSER Zone Atelier Armorique (https://deims.org/31e67a47-5f15-40ad-9a72-f6f0ee4ecff6). A participatory approach was employed to develop five future LUCC scenarios incorporating BGINs. Narrative descriptions were then used as input for the FORESCEM model to simulate LUCC dynamics (Fig. 1 - Houet et al. 2022). The impacts on biodiversity were assessed by evaluating changes in landscape connectivity for woodlands, grasslands, and wetlands using the model developed by Boussard et al. (2020). Additionally, the effects on water quality and quantity were analyzed under LUCC and RCP8.5 climate change scenarios using the model developed by Álvarez-Cabria et al. (2016). The effectiveness of BGIN policies was assessed by comparing current landscape connectivity (2018) with projected connectivity in 2050 and by estimating future water quality. Results indicate that despite integrating BGINs, the projected impacts on biodiversity (Fig. 2) and water resources could still be significantly negative. Key drivers of future agricultural land-use changes and related environmental impacts include evolving CAP priorities, demographic trends among farmers, and climate change. While BGINs are effective in mitigating urbanization impacts, they may not be sufficient at the landscape scale. This study highlights the necessity of systemic environmental policies that foster synergies among different administrative services involved in land management. The current sectoral (or "siloed") organisation levels remain a barrier to achieving land sustainability goals. While LUCC simulations are designed to assist decision-makers in implementing sustainable policies, we examined whether our results effectively support local stakeholders in the Couesnon watershed. We conducted 14 public meetings involving nearly 150 participants, including farmers, policymakers, land and resource management professionals, and students. Surveys and interviews conducted during the meetings and 6 to 12 months later revealed that while scenario-based approaches can influence decision-making, their impact requires time to materialize (Rigo and Houet 2023, Rigo et al. 2024). These findings underscore the need for further research and the importance of effectively communicating scientific insights to support the understanding, monitoring, and sustainable management of socio-ecological systems within the critical zone.

Critical below-ground drought effects on temperate trees – insights from six years of ecophysiological monitoring and two years of rain exclusion

Climate change, including a reduction in precipitation, increased atmospheric moisture demand, and drying soils, threaten the life-supporting function in trees. In response, trees can exhibit different below-ground drought acclimation strategies, including increased root-water uptake depth and root growth to increase water supply. We initiated a long-term monitoring experiment at the Swiss Canopy Crane II (SCCII) site in Switzerland in 2018, including a rainfall exclusion of 50% during the vegetation period (April-October) since 2023. The SCCII site provides growing conditions representative of a central European mid-mountain range forest and hosts 10 co-occurring European temperate tree species. For six years, we measured the δ2H and δ18O values of samples collected from tree xylem, soil water in different depths, and precipitation, as well as a multitude of ecophysiological measurements within a great range of environmental conditions (wet and dry), including the exceptionally dry summer in 2023. The extreme conditions in 2023 caused canopy dieback and mortality in individuals of Fagus sylvatica, Picea abies, and Abies alba in the drought treatment indicating critically low soil water supply. We utilized the data to parameterize the hydrological model LWFBrook90.jl with the goal of simulating soil moisture, soil water potential and soil water isotope transport, as well as root water uptake depth under different environmental conditions. By quantifying the temporal origins of root water uptake and running scenarios of further increased drought conditions, we will quantify the access of different tree species to soil water from various depths and the soil water residence time. Moreover, we will quantify how soil water residence time and, thus, the supply of water to tree species at different soil depths varies under different climate change scenarios. First results show that depending on the severity of drought and tree water consumption, the soil water is used up almost entirely within one growing season indicating the vital role of summer precipitation and winter-time refilling. We expect the final results of this study to provide us with valuable insights on soil water retention time and the temporal dynamics of root water uptake under various drought conditions. These findings will increase our understanding critical below-ground drought effects and acclimation of temperate trees.

The impact of stratospheric aerosol injection: a regional case study

Stratospheric aerosol injection (SAI) is a form of climate intervention that has been proposed to limit future warming and mitigate some of the adverse impacts of climate change while humanity continues efforts to reduce emissions and atmospheric concentrations of greenhouse gases. In this study, we use an Earth system model to compare the projected effects of a climate change scenario to three different SAI scenarios. Our analysis centers on both climate and crop productivity impacts. We focus on four Global South regions: South Asia, East Asia, South Central America, and West Africa. These regions were selected due to their socioeconomic vulnerability to climate change. The SAI scenarios project reduced temperature extremes and greater wet season precipitation, soil moisture and crop productivity compared to the climate change scenario over all four regions. We also find that the extent to which SAI mitigates crop productivity declines due to climate change is likely greater in South Central America and West Africa than in South and East Asia. Our study is a step toward addressing the need for more regional analyses of the potential impacts of different SAI scenarios.

Deep learning meets tree phenology modelling: PhenoFormer versus process‐based models

Abstract Predicting phenology, that is the timing of seasonal events of plant life such as leaf emergence and colouration in relation to climate fluctuations, is essential for anticipating future changes in carbon sequestration and tree vitality in temperate forest ecosystems. Existing approaches typically rely on either hypothesis‐driven process models or data‐driven statistical methods. Several studies have shown that process models outperform statistical methods when predicting under climatic conditions that differ from those of the training data, such as for climate change scenarios. However, in terms of statistical methods, deep learning approaches remain underexplored for species‐level phenology modelling. We present a deep neural architecture, PhenoFormer, for species‐level phenology prediction using meteorological time series. Our experiments utilise a country‐scale data set comprising 70 years of climate data and approximately 70,000 phenological observations of nine woody plant species, focussing on leaf emergence and colouration in Switzerland. We extensively compare PhenoFormer to 18 different process‐based models and traditional machine learning methods, including Random Forest (RF) and Gradient Boosted Machine (GBM). Our results demonstrate that PhenoFormer outperforms traditional statistical methods in phenology prediction while achieving significant improvements or comparable performance to the best process‐based models. When predicting under climatic conditions similar to the training data, our model improved over the best process‐based models by 6% normalised root‐mean‐squared error (nRMSE) for spring phenology and 7% nRMSE for autumn phenology. Under conditions involving substantial climatic shifts between training and testing (+1.21°C), PhenoFormer reduced the nRMSE by an average of 8% across species compared to RF and GBM, and performed on par with the best process models. These findings highlight the potential of deep learning for phenology modelling and call for further research in this direction, particularly for future climate projections. Meanwhile, the advancements achieved by PhenoFormer can provide valuable insights for anticipating species‐specific phenological responses to climate change.

The Evolution of Runoff Processes in the Source Region of the Yangtze River Under Future Climate Change

Climate change has intensified the melting of glaciers and permafrost in high-altitude cold regions, leading to more frequent extreme hydrological events. This has caused significant variations in the spatiotemporal distribution of meltwater runoff from the headwater cryosphere, posing a major challenge to regional water security. In this study, the HBV hydrological model was set up and driven by CMIP6 global climate model outputs to investigate the multi-scale temporal variations of runoff under different climate change scenarios in the Tuotuo River Basin (TRB) within the source region of the Yangtze River (SRYR). The results suggest that the TRB will undergo significant warming and wetting in the future, with increasing precipitation primarily occurring from May to October and a notable rise in annual temperature. Both temperature and precipitation trends intensify under more extreme climate scenarios. Under all climate scenarios, annual runoff generally exhibits an upward trend, except under the SSP1-2.6 scenario, where a slight decline in total runoff is projected for the late 21st century (2061–2090). The increase in total runoff is primarily concentrated between May and October, driven by enhanced rainfall and meltwater contributions, while snowmelt runoff also shows an increase, but accounts for a smaller percentage of the total runoff and has a smaller impact on the total runoff. Precipitation is the primary driver of annual runoff depth changes, with temperature effects varying by scenario and period. Under high emissions, intensified warming and glacier melt amplify runoff, while low emissions show stable warming with precipitation dominating runoff changes.

Changes in the Distribution Range of the Genus Cardiocrinum in China Under Climate Change and Human Activities.

Cardiocrinum are perennial herbaceous plants of the Liliaceae family with high ornamental, nutritional, and medicinal value. However, critical knowledge gaps remain regarding the following: (1) the fine-scale habitat preferences of Cardiocrinum; (2) the key ecological drivers influencing their growth and distribution. The MaxEnt software 3.4.1 was used to simulate the current and future suitable habitats of Cardiocrinum, evaluate the impacts of environmental changes on its distribution, and determine the distribution changes under climate change scenarios. The AUC value of the model used in the current study was >0.98, which indicates that the model had good accuracy. The results show that as a typical understory herb, precipitation in the warmest quarter (bio18) and temperature seasonality (bio04) are the main factors affecting the distribution of Cardiocrinum. In addition, Cardiocrinum giganteum and Cardiocrinum giganteum var. yunnanense are also affected by slope and human activity. Under the SSP126, SSP245, and SSP585 climate scenarios, the suitable habitat areas of Cardiocrinum cathayanum and C. giganteum showed an increasing trend. The suitable habitat area of C. giganteum var. yunnanense increased under the SSP126 climate scenario; however, it substantially declined in SSP245 and SSP585 scenarios. The distribution area of Cardiocrinum shifted to higher latitudes. The centroid of C. cathayanum shifted more than 5 degrees of latitude during SSP585 2081s, while the centroid of C. giganteum and C. giganteum var. yunnanense did not shift more than 2 degrees of latitude. In addition, the centroid longitudes of C. giganteum and C. giganteum var. yunnanense shifted westward under the three climate scenarios. There is ecological niche differentiation among C. cathayanum and others, whilst C. giganteum and C. giganteum var. yunnanense have overlapping ecological niches. In the future, we will strengthen the protection of wild Cardiocrinum resources in accordance with environmental factors and suitable habitats for Cardiocrinum.

Growth Response and Cell Permeability of the Fish-Killing Phytoflagellate Heterosigma akashiwo Under Projected Climate Conditions.

Climate change and anthropogenic alterations in biogeochemical cycles are intensifying the frequency, duration, and potential toxicity of harmful algal blooms (HABs) in marine ecosystems. However, these effects are highly variable and depend on species identity, strain-specific traits, and local environmental conditions. Key drivers include rising sea surface temperatures, changes in salinity resulting from altered precipitation patterns and runoff, and elevated CO2 levels leading to ocean acidification. Heterosigma akashiwo, a euryhaline raphidophyte responsible for the widespread killing of fish, is particularly responsive to these changes. This study investigated the combined effects of temperature, salinity, and CO2 concentration on the growth, yield, and cell membrane permeability of H. akashiwo using a Design of Experiment (DOE) approach. DOE facilitates a detailed and systematic analysis of multifactorial interactions, enabling a deeper understanding of complex relationships while maximizing efficiency and minimizing the use of experimental resources. The results revealed that growth and yield were maximized at higher temperatures and salinities, whereas cell permeability increased under cooler, less saline, and lower CO2 conditions. These findings suggest that projected future ocean conditions may enhance biomass production while potentially reducing cellular permeability and, by extension, toxicity. This study highlights the value of the DOE framework in identifying key interactions among environmental drivers of HABs, offering a practical foundation for future predictive modeling under climate change scenarios.

Invasion Status, Mechanisms, and Future Distribution Prediction of Solidago canadensis in the Trade Port Region: A Case Study of Ningbo Port, China.

Trade ports are the first places where alien species invade and the source of their spread to other areas. Controlling invasions in these regions can effectively reduce invasion pressure and disrupt the spread pathways of invasive species, thereby significantly reducing their threat to local ecosystems and biodiversity loss. Based on 595 field survey plots, the Generalized Linear Model (GLM) and Species Distribution Model (MaxEnt) were employed to analyze and predict the invasion mechanisms and future possible distribution of Solidago canadensis in the Ningbo Port, China. The results indicate that the invasion of S. canadensis in the Ningbo Port was particularly severe, with a 67.7% occurrence rate of all sampling plots in the field survey, and a risk level classified as Grade 1. Biodiversity (p < 0.001) and the minimum temperature of the coldest month (p < 0.01) significantly affect the invasiveness. Highly diverse communities could resist the invasion of alien species, which support Elton's diversity-invasibility hypothesis. Low temperatures had a restrictive effect on the invasion of S. canadensis. The total suitable area continued to expand under three different climate change scenarios compared to current conditions (increased by 3.73%, 5.67%, and 3.74% by the 2070s). The total potential habitat area of S. canadensis reached its maximum extent (89.77%) under the medium greenhouse gas emission scenario in the 2050s. Meanwhile, the medium suitable area exhibited the greatest fluctuation among the three climate scenarios. Under the low emission condition, the medium suitable area of S. canadensis diminished by 63.10 km2, but in the medium and high emission condition, its area expanded by 91.13 km2 and 16.20 km2, respectively. Under future climate warming scenarios, the invasion risk of S. canadensis in Ningbo Port will continue to increase. The results of our study reveal the diffusion mechanisms of invasive plants at the colonization source, providing important theoretical support for invasive alien species' initial prevention and control.

Protected from Pterygoplichthys? Predicting thermal habitat suitability for nonnative armored catfish in the Suwannee River

ABSTRACT Objective Nonnative fishes can modify ecosystems and harm economies when they are introduced to new environments. Climate change is likely to assist the spread and establishment of some nonnative fishes (e.g., warmwater species), but spatiotemporal gaps in water temperature monitoring and modeling may prevent ecologists and managers from forecasting thermal habitat suitability for these taxa. The purpose of this study was to develop a predictive model of winter water temperatures and thermal habitat suitability for two priority nonnative armored catfish, Vermiculated Sailfin Catfish Pterygoplichthys disjunctivus and Orinoco Sailfin Catfish P. multiradiatus, in the Suwannee River, Florida and Georgia. Methods Precipitation- and groundwater-corrected air–water temperature models were developed and evaluated using a model selection procedure to predict water temperatures at four sites in the Suwannee River. These models were chosen because they blend the simplicity of air–water temperature models with the accuracy of hydrometeorological models to create an efficient, economical, management-relevant approach for analyzing and forecasting water temperature. Results Most of the top-performing water temperature models (92%) had precipitation or groundwater corrections to air–water temperature formulations. Projected mean and maximum water temperatures increased as simulated climate change intensified. All four Suwannee River sites studied were projected to be thermally hospitable to the survival of Vermiculated Sailfin Catfish. Lower river sites, noticeably warmer than upper river sites, were conducive to the survival of Orinoco Sailfin Catfish throughout the winter months. The upper river sites were too cold for Orinoco Sailfin Catfish survival in some climate-change scenarios, but the Suwannee River has an abundance of constant-temperature springs that are likely hospitable to Vermiculated Sailfin Catfish and Orinoco Sailfin Catfish throughout the year. Conclusions The findings suggest that winter water temperatures will likely not be a barrier to the survival of Pterygoplichthys catfish in the Suwannee River, amplifying the importance of conservation and management approaches to inhibit their spread and establishment. If the Pterygoplichthys population remains small and isolated and decision makers are able to devote required staff time and resources to managing these species, removal and eradication at local if not broader scales may be reasonable goals. This study provides a water temperature modeling approach that can aid ecologists and managers in prioritizing sites to prevent the introduction, slow the dispersal, eradicate, and control Pterygoplichthys catfish and other nonnative fishes in the Suwannee River and beyond.

Unprecedented rainfall events increase the magnitude of design storms

Abstract Climate change, driven by human activities and increasing greenhouse gas emissions, is pushing Earth's climate toward a warmer state, as evidenced by long-term observations. The frequency and intensity of unprecedented rainfall events have increased in recent years, underscoring the urgent need to revise design storms and Depth-Duration Frequency (DDF) curves to better adapt to and mitigate the impacts of climate change. This study used a serial type of Stochastic Rainfall Generator (SRG) that is capable of simulating daily rainfall series by embedding unprecedented events to study extreme precipitation scenarios under the changing climate. By perturbing values of power law tuning parameters in the SRG model, we developed thirty-six precipitation scenarios, some of which directly correlate with the current climate change scenario, while others represent very extreme conditions. High-performance computing is employed to run the computationally intensive SRG for simulating thirty-six scenarios across the entire Indian region. These simulated scenarios were analyzed to prepare rainfall return level maps and DDF curves. The findings reveal substantial increases in rainfall return levels across all frequencies when unprecedented events are considered, with pronounced impacts in coastal, northeastern, and Himalayan regions. The spatial pattern of simulated extreme precipitation was consistent across all generated scenarios from SRG irrespective of the return periods. Minimal spatial uncertainty in return level estimates across climate zones is observed which confirms the robustness of the SRG model and spatial clusters of extreme rainfall are identified irrespective of SRG being a point model. The analysis in this study based on SRG simulated climate change scenarios offers crucial insights for revising design storms and for devising climate resilience and flood management strategies.

Crop acreage portfolio analysis of introducing more hemp in Kentucky

AbstractIntroducing new crops or promoting the incorporation of environmentally beneficial crops into agricultural fields could alter acreage, crop mix, and on‐farm revenue. For instance, promoting hemp in Kentucky is expected to shift the crop mix to align with producers’ desire to maximize profitability. Despite the perceived benefits of crop portfolio changes with new or promoted crops, less attention has been given to their analysis and modeling due to the complexity of handling multiple outputs. We employed a Dirichlet regression model to address this gap, using county‐level hemp production data in Kentucky (2020–2022) from the USDA Farm Service Agency, along with weather, geographical, and production variables. We first estimated the response parameters to describe changes in crop ratios in Kentucky counties in the midterm, assuming no innovative changes in production technology and an extensive margin of agricultural expansion. Subsequently, we projected potential changes under 14 representative price and climate change scenarios and discussed the effects on harvested acres and revenue by crops. Our findings highlighted that short‐term price variation could drive a corn‐ or soybean‐dominant crop mix to sustain stable on‐farm revenue, potentially countering hemp promotion objectives. Furthermore, we explored the implications of substitution and complementary relationships among crops, suggesting that consumption‐driven policies could mitigate price volatility and enhance hemp's market stability. We also found that policy considerations were necessary due to the profound negative impact of climate change on long‐term hemp‐based farm revenue, stemming from its vulnerability to temperature stress.

Analysis of the Projected Climate Impacts on the Interlinkages of Water, Energy, and Food Nexus Resources in Narok County, Kenya, and Vhembe District Municipality, South Africa

The current changing climate requires the development of water–energy–food (WEF) nexus-oriented systems capable of mainstreaming climate-smart innovations into resource management. This study demonstrates the cross-sectoral impacts of climate change on interlinked sectors of water, energy, and food in Narok County, Kenya, and Vhembe District, South Africa. This study used projected hydroclimatic extremes across past, present, and future scenarios to examine potential effects on the availability and accessibility of these essential resources. The projected temperature and rainfall are based on nine dynamically downscaled Coupled Model Intercomparison Project Phase 5 (CMIP 5) of the Global Climate Models (GCMs). The model outputs were derived from two IPCC “Representative Concentration Pathways (RCPs)’’, the RCP 4.5 “moderate scenario”, and RCP 8.5 “business as usual scenario”, also defined as the addition of 4.5 W/m2 and 8.5 W/m2 radiative forcing in the atmosphere, respectively, by the year 2100. For the climate change projections, outputs from the historical period (1976–2005) and projected time intervals spanning the near future, defined as the period starting from 2036 to 2065, and the far future, spanning from 2066 to 2095, were considered. An ensemble model to increase the skill, reliability, and consistency of output was formulated from the nine models. The statistical bias correction based on quantile mapping using seven ground-based observation data from the South African Weather Services (SAWS) for Limpopo province and nine ground-based observation data acquired from the Trans-African Hydro-Meteorological Observatory (TAHMO) for Narok were used to correct the systematic biases. Results indicate downscaled climate change scenarios and integrate a modelling framework designed to depict the perceptions of future climate change impacts on communities based on questionnaires and first-hand accounts. Furthermore, the analysis points to concerted efforts of multi-stakeholder engagement, the access and use of technology, understanding the changing business environment, integrated government and private sector partnerships, and the co-development of community resilience options, including climate change adaptation and mitigation in the changing climate. The conceptual climate and WEF resource modelling framework confirmed that future climate change will have noticeable interlinked impacts on WEF resources that will impact the livelihoods of vulnerable communities. Building the resilience of communities can be achieved through transformative WEF nexus solutions that are inclusive, sustainable, equitable, and balance adaptation and mitigation goals to ensure a just and sustainable future for all.

Shrub encroachment modifies soil properties through plant resource economics traits

Abstract Background and aims Shrub encroachment alters ecosystem functions. Yet, changes in plant community traits and soil properties along succession from grassland to shrubland in European mountains are poorly understood. Methods We used a trait-based approach to investigate the indirect effects of shrubs from community weighted means (CWM) of plant traits to soil properties along a gradient of encroachment in subalpine grasslands at two sites in the Alps. We hypothesized that increasing shrub density shifts plant communities towards more conservative traits, which nonlinearly increases carbon sequestration and impacts nutrient cycling. We tested our hypothesized model of indirect effects using structural equation models, which accounted for biomass allocation to leaves and stems in CWM calculations. Results As expected, CWM dry matter content (DMC) increased and CWM of nitrogen (N) and phosphorus (P) decreased with increasing shrub biomass. Increasing CWM DMC resulted in increasing soil C:N ratio and soil organic matter (SOM) concentration, and decreasing pH. Decreasing CWM P resulted in decreasing soil available P, but changes in CWM N had no effect on available N. There was no indication of nonlinear changes. Conclusion This study demonstrates that with shrub encroachment plant communities gradually become more conservative with tougher and nutrient-poor tissues, which leads to soil acidification, SOM accumulation and lower P availability. We also demonstrate that DMC, an easy measurable trait, is a sufficient indicator for effects of plant tissue quality on soils of shrub encroached subalpine grasslands and could be used in future trait-based models, allowing projections under climate change scenarios.

Modeling parasitoid development: climate change impacts on Telenomus remus (Nixon) and Trichogramma foersteri (Takahashi) in southern Brazil.

The egg parasitoids Telenomus remus (Nixon) and Trichogramma foersteri (Takahashi) were recently collected in southern Brazil, expanding their potential use in biological control. Understanding how these species respond to temperature is essential to the effective implementation of biological control programs, especially in the context of global warming. In this study, phenological models were employed to assess the effects of temperature and climate change on their development. Temperature had a significant impact on the development of Te. remus, with development times ranging from 52.7 days at 15 °C to 8.1 days at 35 °C. Parasitism peaked at 35 °C (124.15 eggs) and lowest at 15 °C (38.5 eggs). Emergence rates declined under extreme temperatures, especially at 15 °C. The Brière-2 and Shi models were identified as the most appropriate for Te. remus and T. foersteri, respectively. Under the SSP2-4.5/2080 scenario, an increase in the number of generations was projected. In contrast, in the SSP5-8.5 scenario, higher temperatures may exceed the thermal thresholds of these species, potentially reducing voltinism in warmer regions while promoting it in colder areas. Telenomus remus and T. foersteri exhibit broad thermal tolerance; however, extreme temperatures, including those predicted under climate change scenarios, can restrict their development. This study offers valuable insights for laboratory rearing programs, mass production, and field release programs while enhancing the understanding of thermal interactions in Hymenopteran parasitoids. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.