Projected Climate Conditions Research Articles

Climate Change, Farming, and Gardening in Alaska: Cultivating Opportunities

Ongoing climate change and associated food security concerns are pressing issues globally, and are of particular concern in the far north where warming is accelerated and markets are remote. The objective of this research was to model current and projected climate conditions pertinent to gardeners and farmers in Alaska. Research commenced with information-sharing between local agriculturalists and climate modelers to determine primary questions, available data, and effective strategies. Four variables were selected: summer season length, growing degree days, temperature of the coldest winter day, and plant hardiness zone. In addition, peonies were selected as a case study. Each variable was modeled using regional projected climate data downscaled using the delta method, followed by extraction of key variables (e.g., mean coldest winter day for a given decade). An online interface was developed to allow diverse users to access, manipulate, view, download, and understand the data. Interpretive text and a summary of the case study explained all of the methods and outcomes. The results showed marked projected increases in summer season length and growing degree days coupled with seasonal shifts and warmer winter temperatures, suggesting that agriculture in Alaska is undergoing and will continue to undergo profound change. This presents opportunities and challenges for farmers and gardeners.

Persistent yet vulnerable: resurvey of an Abies ecotone reveals few differences but vulnerability to climate change.

Climate change is shifting forest tree species distributions across elevational and latitudinal gradients, and these changes are often pronounced at ecotones where species meet their climatic bounds and are replaced by other species. Using an extensive ecotone composed of lower-montane white fir (Abies concolor var. lowiana) and upper-montane red fir (Abies magnifica var. magnifica) in the central Sierra Nevada range of California, USA, we (1) examined how the demographics of the ecotone have responded to recent climate using a field observational study and a historical dataset, (2) quantified climate drivers across species life stages using contemporary demographic data, and (3) tested the potential impacts of future climate on species-specific seedling survival and growth in a fully factorial growth chamber experiment that varied temperature, growing season length, and water availability. A re-examination of the ecotone midpoint after 35 yr suggested a reduction in A. concolor sapling and tree densities and a rise in A. magnifica proportional dominance between surveys. Seedling abundances across the ecotone indicated that A. magnifica tends to dominate the regeneration layer and currently forms an important component of the seedling community at elevations below those where A. magnifica saplings or trees begin to co-dominate stands. Observational and experimental assessments suggest that temperature and precipitation serve as important drivers, differentiating A. concolor vs. A. magnifica distributions, and are primary stressors at the seedling stage. Seedlings of both species were adversely affected by experimental climate treatments, although A. concolor exhibited greater survival and a more conservative growth strategy under extreme climatic stress than A. magnifica. Projections indicate that historical climate conditions will rise by an amount greater than the ecotone's current elevational extent by the end of the 21st century. Differential drivers of species abundances suggest that the projected climate will expand conditions that promote A. concolor abundance and impede A. magnifica abundance across the ecotone; however, disturbance activity and microclimatic conditions will also influence regeneration and overstory tree dynamics. Our study demonstrates the importance of quantifying species-specific responses to climate and indicates that widespread regeneration failure may be one possible consequence in which species exhibit strong sensitivity to projected climate conditions.

A generic risk assessment framework to evaluate historical and future climate-induced risk for rainfed corn and soybean yield in the U.S. Midwest

Fluctuations in temperature and precipitation are expected to increase with global climate change, with more frequent, more intense and longer-lasting extreme events, posing greater challenges for the security of global food production. Here we proposed a generic framework to assess the impact of climate-induced crop yield risk under both current and future scenarios by combining a stochastic model for synthetic climate generation with a well-validated statistical crop yield model. The synthetic climate patterns were generated using the extended Empirical Orthogonal Function method based on historically observed and projected climate conditions. We applied our framework to assess the corn and soybean yield risk in the U.S. Midwest for historical and future climate conditions. We found that: (1) in the U.S. Midwest, about 45% and 40% of the interannual variability in corn and soybean yield, respectively, can be explained by the climate; (2) the risk level is higher in the southwest and northwest regions of the U.S. Midwest corresponding to 25% yield reduction for both corn and soybean compared to other regions; (3) the severity for the 1988 and 2012 major droughts quantified by our method represent 21-year and 30-year events for corn, and 7-year and 12-year events for soybean, respectively; (4) the crop yield risk will increase under a future climate scenario (i.e., Representative Concentration Pathway 8.5 or RCP 8.5 at 2050) compared with the current climate condition, with averaged yield decreases and yield variability increases for both corn and soybean. The framework and the results of this study enable applications for risk management policies and practices for the agriculture sectors.

Using hydrologic landscape classification and climatic time series to assess hydrologic vulnerability of the western U.S. to climate.

We apply the hydrologic landscape (HL) concept to assess the hydrologic vulnerability of the western United States (U.S.) to projected climate conditions. Our goal is to understand the potential impacts of hydrologic vulnerability for stakeholder-defined interests across large geographic areas. The basic assumption of the HL approach is that catchments that share similar physical and climatic characteristics are expected to have similar hydrologic characteristics. We use the hydrologic landscape vulnerability approach (HLVA) to map the HLVA index (an assessment of climate vulnerability) by integrating hydrologic landscapes into a retrospective analysis of historical data to assess variability in future climate projections and hydrology, which includes temperature, precipitation, potential evapotranspiration, snow accumulation, climatic moisture, surplus water, and seasonality of water surplus. Projections that are beyond 2 standard deviations of the historical decadal average contribute to the HLVA index for each metric. Separating vulnerability into these seven separate metrics allows stakeholders and/or water resource managers to have a more specific understanding of the potential impacts of future conditions. We also apply this approach to examine case studies. The case studies (Mt. Hood, Willamette Valley, and Napa–Sonoma Valley) are important to the ski and wine industries and illustrate how our approach might be used by specific stakeholders. The resulting vulnerability maps show that temperature and potential evapotranspiration are consistently projected to have high vulnerability indices for the western U.S. Precipitation vulnerability is not as spatially uniform as temperature. The highest-elevation areas with snow are projected to experience significant changes in snow accumulation. The seasonality vulnerability map shows that specific mountainous areas in the west are most prone to changes in seasonality, whereas many transitional terrains are moderately susceptible. This paper illustrates how HL and the HLVA can help assess climatic and hydrologic vulnerability across large spatial scales. By combining the HL concept and HLVA, resource managers could consider future climate conditions in their decisions about managing important economic and conservation resources.

Speculation for quantifying increased C4 plants under future climate conditions: Inner Mongolia, China case study

Alternating conditions from cold to warm periods since the Late Glacial provided a significant contrast for future hydroclimatic variation, as did the corresponding variation in vegetation. To predict the potential variability in C3/C4 biomass under future warmer climatic conditions, we determined the current spatiotemporal distribution of C3 and C4 vegetation by estimating the variability of δ13Corg values in 125 topsoil samples and investigating the geological period variability of C4 plants growing in Inner Mongolia, China. We examined the factors contributing to the growth of C4 plants and the variability in C4 plants for each 1 °C increase in temperature during recent and geological times. The results revealed that the relative abundance of C4 plants in Inner Mongolia shows an increasing trend from the northwest to the southeast. The biomass of C4 plants was found to be positively correlated with temperature, although weakly correlated with precipitation, thereby indicating that temperature is the primary climatic factor determining the growth of C4 plants in this region. Furthermore, we found that in response to each 1 °C increase in temperature, there would be an approximate 2.1% increase in the spatiotemporal variation of present-day C4 plant biomass in Inner Mongolia, whereas during the geological period, there was a corresponding increase of 10.7%. Comparatively, the spatiotemporal variation in present-day C4 biomass on the Chinese Loess Plateau has undergone a 4.0% increase in response to each 1 °C increase in temperature, whereas 6.0% and 7.5% increases in the geological period were estimated based on core samples taken from the Lantian and Xingyang sections, respectively. Interestingly, for each 1 °C increase in temperature during the current growth month of C4 plants, there is a 6.6% increase in C4 biomass, which is essentially consistent with the results obtained for the geological period results (i.e., 6.0% and 7.5% for the Lantian and Xingyang sections, respectively). The findings of this study reveal a distinct contrast in the variation of C4 plants during recent and geological periods, thereby enabling us to quantitatively estimate the potential changes in C4 vegetation in response to projected climate conditions.

Projection of Hydro-Climatic Extreme Events under Climate Change in Yom and Nan River Basins, Thailand

Due to a continuous increase in global temperature, the climate has been changing without sign of alleviation. An increase in the air temperature has caused changes in the hydrologic cycle, which have been followed by several emergencies of natural extreme events around the world. Thailand is one of the countries that has incurred a huge loss in assets and lives from the extreme flood and drought events, especially in the northern part. Therefore, the purpose of this study was to assess the hydrological regime in the Yom and Nan River basins, affected by climate change as well as the possibility of extreme floods and droughts. The hydrological processes of the study areas were generated via the physically-based hydrological model, namely the Soil and Water Assessment Tool (SWAT) model. The projected climate conditions were dependent on the outputs of the Global Climate Models (GCMs) as the Representative Concentration Pathways (RCPs) 2.6 and 8.5 between 2021 and 2095. Results show that the average air temperature, annual rainfall, and annual runoff will be significantly increased in the intermediate future (2046–2070) onwards, especially under RCP 8.5. According to the Flow Duration Curve and return period of peak discharge, there are fluctuating trends in the occurrence of extreme floods and drought events under RCP 2.6 from the future (2021–2045) to the far future (2071–2095). However, under RCP 8.5, the extreme flood and drought events seem to be more severe. The probability of extreme flood remains constant from the reference period to the near future, then rises dramatically in the intermediate and the far future. The intensity of extreme droughts will be increased in the near future and decreased in the intermediate future due to high annual rainfall, then tending to have an upward trend in the far future.

Investigating the Effects of Agricultural Water Management in a Mediterranean Coastal Aquifer under Current and Projected Climate Conditions

Coastal delta plains are areas with high agricultural potential for the Mediterranean region because of their high soil fertility, but they also constitute fragile systems in terms of water resources management because of the interaction of underlying aquifers with the sea. Such a case is the Pinios River delta plain located in central Greece, which also constitutes a significant ecosystem. Soil and Water Assessment Tool (SWAT) and SEAWAT models were combined in order to simulate the impact of current water resources management practices in main groundwater budget components and groundwater salinization of the shallow aquifer developed in the area. Moreover, potential climate change impact was investigated using climate data from Regional Climate Model for two projected periods (2021–2050 and 2071–2100) and two sea level rise scenarios (increase by 0.5 and 1 m). Modeling results are providing significant insight: although the contribution of the river to groundwater inflows is significant, direct groundwater recharge from precipitation was found to be higher, while capillary rise constitutes a major part of groundwater outflows from the aquifer. Moreover, during the simulation period, groundwater flow from the aquifer to the sea were found to be higher than the inflows of seawater to the aquifer. Regarding climate change impact assessment, the results indicate that the variability in groundwater recharge posed by the high variability of precipitation during the projected periods is increasing the aquifer’s deterioration potential of both its quantity and quality status, the latter expressed by the increased groundwater Cl− concentration. This evidence becomes more significant because of the limited groundwater storage capacity of the aquifer. Concerning sea level rise, it was found to be less significant in terms of groundwater salinization impact compared to the decrease in groundwater recharge and increase in crop water needs.

Risk of invasiveness of non-native aquatic species in the eastern Mediterranean region under current and projected climate conditions

Human-induced biological introductions pose a major threat to global biodiversity, and this is especially frequent in the eastern Mediterranean region, which is a globally important biodiversity hotspot area of high conservation value. To predict at which level introduced species in this region might become invasive under current and projected climate conditions, 232 non-native aquatic organisms were screened using the Aquatic Species Invasiveness Screening Kit. Based on receiver operative characteristic curve analysis, thresholds were identified to distinguish between low, medium and high risk species. The “top invasive” (very high risk) species identified were: brown bullhead Ameiurus nebulosus, blue crab Callinectes sapidus, gibel carp Carassius gibelio, Philippine catfish Clarias batrachus, Chinese mitten crab Eriocheir sinensis, bluespotted cornetfish Fistularia commersonii, silver carp Hypophthalmichthys molitrix, silver-cheeked toadfish Lagocephalus sceleratus, half-smooth golden pufferfish Lagocephalus spadiceus, Suez pufferfish Lagocephalus suezensis, signal crayfish Pacifastacus leniusculus, fathead minnow Pimephales promelas, channeled applesnail Pomacea canaliculata, red swamp crayfish Procambarus clarkii, devil firefish Pterois miles and European catfish Silurus glanis. The risk of being invasive of more than half of the screened species increased after taking global warming predictions into account, and several species considered to be globally invasive (cf. high risk) were classified as posing only a medium risk for the eastern Mediterranean region. Region-specific risk screenings, as implemented in this study, are therefore essential for setting priorities in preventative management for the conservation of key biodiversity hotspots and the optimal allocation of resources in view of full risk assessment for the species identified as (very) high risk.

Earth–Air Heat Exchanger Geo-Climatic Suitability for Projected Climate Change Scenarios in the Americas

Earth–air heat exchangers (EAHE) provide heating and cooling that is intrinsically tied to the climate of the surrounding environment. A climate-based approach was applied to 273 sites for both historical and projected climate conditions, with the latter being defined by three different Representative Concentration Pathways (RCPs) from the CMIP5 collection of Global Circulation Models (GCMs). Changes to heating and cooling degree hours as well as heating and cooling capacity were estimated and used to classify geo-climatic suitability. The analysis revealed cooler climates will retain their ability to provide cooling despite increasing cooling needs driven by warming temperatures. On the other hand, warmer, more tropical, climates will observe reduced suitability as cooling demand grows. The magnitude and variability of the changes in EAHE potential were greatest for the RCP8.5 scenario during the 2061–2090 time period, particularly for regions with a comparable mix of heating and cooling needs. Ultimately, the results demonstrate that future EAHE suitability is climate dependent, with cooler climates being relatively resistant to changes when compared to warmer climates. The results can be used by stakeholders to find useful climate analogs for their sites of interest to consider the potential impact of global climate change on EAHE usability.

Simulated deficit irrigation and climate change effects on sunflower production in Eastern Colorado with CSM-CROPGRO-Sunflower in RZWQM2

Sunflower (Helianthus annuus L.) has been used as an alternative summer crop in the traditional wheat (Triticum aestivum L.)-fallow rotation in the Great Plains of the USA. However, few studies have been conducted to quantify sunflower productivity and water productivity (WP) under semi-arid conditions and projected climate change. Experiments were conducted in 2008, 2010, and 2011 on sunflowers under deficit irrigation to meet a fraction of crop evapotranspiration (ETc) as estimated by FAO-56 in eastern Colorado. The field data was used to calibrate and validate the CSM-CROPGRO-Sunflower model that is incorporated in the Root Zone Water Qualify Model (RZWQM2). The calibrated model was then used to simulate sunflower production under projected climate conditions with four Representative Concentration Pathways (RCP) scenarios (2.6, 4.5, 6.0, and 8.5) and four irrigation levels (100%, 60%, 40% ETc and rainfed) in the late 21st century. The results showed that the model was able to adequately simulate sunflower biomass, yield, and soil water storage under the different irrigation treatments in all three years. The corresponding relative root mean square deviation (RRMSD) values were between 0.05 and 0.15 for the simulations of soil water storage, yield, and biomass. Under future climate change conditions, the model simulated greater impact of irrigation treatments than RCP scenarios on sunflower production. For example, yield was 3251.3, 2638.85 and 1937.17 kg ha−1 with 100%, 60% and 40% ETc irrigation under baseline (1992–2013) and was 2932.47, 2360.53 and 1810.65 kg ha−1 with these irrigation treatments under RCP8.5 (2070–2091). Simulation results also showed that scheduling irrigations based on 60% of ETc was the best choice for sunflower WP in eastern Colorado. Climate change did not affect sunflower biomass, yield, and WP. There was an increasing trend of irrigation amount was simulated from the baseline to RCP8.5 scenario to maintain a certain percent of ETc due to high temperature projected. For instance, the irrigation amount for 100%, 60% and 40% of ETc irrigation treatment was 16.4%, 17.3%, and 20.0% higher under RCP8.5 than those under baseline conditions with CO2 fertilization. Finally, our results demonstrated that RZWQM2 can be used to effectively schedule sunflower irrigations based on crop evapotranspiration requirement.

Hurricane Hazard Assessment Along the United States Northeastern Coast: Surface Wind and Rain Fields Under Changing Climate

Surface wind and rain fields are two significant elements of hurricane-induced hazards in coastal areas. Mitigation of losses due to hurricane wind and rain hazards has become an increasing urgent and challenging issue in light of changing climate and continued escalation of coastal population density, prompting the need for a more advanced risk analysis methodology to take global warming effects into consideration. In this study, the assessment of hurricane surface wind and rain hazards under changing climate is achieved by performing three simulation components, namely an enhanced hurricane track model to generate the synthesized storms (including a physics-based intensity model integrating sea surface temperature (SST), wind shear, and convective instability contributions), a newly developed thermal wind balance-based model to simulate the gradient wind profiles (explicitly considering environmental conditions of SST, temperature at the top of atmospheric boundary layer, and outflow temperature), and a height-resolving boundary-layer model to obtain the surface wind and rain fields (reducing inherent uncertainties associated with conventionally used gradient-to-surface wind speed conversion factors). A total of 10,000 years of hurricane events are generated for both observed (historical) and projected climate conditions, and a systematical comparison between these two scenarios is investigated. The simulation and comparison results highlight the important effects of a global warming scenario on hurricane surface wind and rain fields, and hence on critical civil infrastructure in hurricane-prone areas.

Analyzing adaptation strategies for maize production under future climate change in Guanzhong Plain, China

Agricultural adaptation is crucial for sustainable farming amid global climate change. By harnessing projected climate data and using crop modeling techniques, the future trends of food production can be predicted and better adaptation strategies can be assessed. The main objective of this study is to analyze the maize yield response to future climate projections in the Guanzhong Plain, China, by employing multiple crop models and determining the effects of irrigation and planting date adaptations. Five crop models (APSIM, AquaCrop, DSSAT, EPIC, and STICS) were used to simulate maize (Zea mays L.) yield under projected climate conditions during the 2030s, 2050s, and 2070s, based on the combination of 17 General Circulation Models (GCMs) and two Representative Concentration Pathways (RCPs 6.0 and 8.5). Simulated scenarios included elevated and constant CO2 levels under current adaptation (no change from current irrigation amount, planting date, and fertilizer rate), irrigation adaptation, planting date adaptation, and irrigation-planting date adaptations. Results from both maize-producing districts showed that current adaptation practices led to a decrease in the average yield of 19%, 27%, and 33% (relative to baseline yield) during the 2030s, 2050s, and 2070s, respectively. The future yield was projected to increase by 1.1–23.2%, 1.0–22.3%, and 2–31% under irrigation, delayed planting date, and double adaptation strategies, respectively. Adaptation strategies were found effective for increasing the future average yield. We conclude that maize yield in the Guanzhong Plain can be improved under future climate change conditions if irrigation and planting adaptation strategies are used in conjunction.

Environmental Drivers of Forage Fishes and Benthic Invertebrates at Multiple Spatial Scales in a Large Temperate Estuary

Vertebrate and invertebrate taxa that serve as forage for predators play a critical role in coastal ecosystems by linking lower trophic levels to ecologically and economically valuable predators in upper trophic levels. We analyzed long-term data from multiple monitoring surveys in Chesapeake Bay and its major tributaries to evaluate patterns and relative abundances of forage at two spatial scales and to identify drivers of forage availability. Time series of forage abundances showed positive spatial correlation, becoming increasingly similar with declining distance between tributaries and regions of Chesapeake Bay. Statistical models were fit to identify relationships among forage taxa and climatic, biological, and environmental variables. Annual abundance indices of many forage taxa were higher in years when spring water temperatures warmed slowly, as indicated by an annual 5 °C degree-day warming index that represented the rate of warming during late winter/early spring. Forage indices also were related (in taxon-specific ways) to winter–spring chlorophyll concentration and freshwater discharge, and to three summer water quality variables: dissolved oxygen, salinity, and water temperature, in addition to a broad-scale climate indicator (Atlantic Multidecadal Oscillation). Our findings broadly demonstrate that bottom–up climate forcing acts to control at least some taxa at lower trophic levels in Chesapeake Bay. Ongoing phenological changes in regional climate and evidence of spatial dependence in responses of forage to environmental conditions underscore the likelihood that spatiotemporal foraging conditions for predator species will change under projected climate conditions.

Hydrologic modeling to examine the influence of the forestry reclamation approach and climate change on mineland hydrology

Forests in the Appalachian region of the U.S. are threatened by a variety of short- and long-term pressures, including climate change, invasive species, and resource extraction. Surface mining for coal is one of the most important drivers of land-use change in the region, reducing native forest cover, causing forest fragmentation, eliminating intact soil, and affecting water resources. The Forestry Reclamation Approach (FRA) has been demonstrated as a successful best practice for restoring forests on mine-impacted landscapes, but little information exists on how the practice will affect hydrologic processes. A study was initiated to examine soil-water movement, as in-situ saturated hydraulic conductivity (Ksat), combined with soil porosity to quantify the potential influence on streamflow of reclaimed mines relative to an unmined, forested control site in eastern Kentucky. We compared different reclamation techniques and time since reclamation to determine the extent to which hydrologic function can be restored. We also simulated evapotranspiration at the watershed scale as a function of reclamation technique for both historical and projected (2050) climate. Results indicate that conventional grassland reclamation critically changes how soil water transitions to streamflow, primarily due to Ksat variability that exceeds that measured for intact and FRA soils. Sites reclaimed using FRA exhibited a soil-water environment that was more similar to the unmined control. However, all reclaimed mine soils were thinner, retained and stored less soil water, and thus could provide less plant-available water during the growing season. The plant-available water stored in reclaimed landscapes may not be sufficient to support forest health and this is exacerbated by projected climate conditions. However, soil development under a combination of FRA techniques has the potential to mitigate this limitation.

Trait-based climate vulnerability of native rodents in southwestern Mexico.

AimIncorporate species’ trait information together with climate projections for associated habitat to assess the potential vulnerability of rodent taxa to climate change.LocationOaxaca State, Mexico.MethodsWe used a trait‐based approach together with climate exposure models to evaluate the vulnerability of rodent species to projected climate conditions in the study region. Vulnerability was estimated based on three factors: (a) Level of climatic exposure that species are projected to experience across their current statewide range; (b) inherent species‐specific sensitivity to stochastic events; and (c) species’ capacity to cope with climate change effects. We defined species as inherently sensitive if they had any of the following: restricted geographic distribution in Mexico; narrow altitudinal range; low dispersal ability; or long generation length.ResultsVulnerability varied depending on the climate change scenario applied. Under the MPI general circulation model and current emissions trends, by 2099, all species evaluated were projected to have some level of threat (vulnerable for at least one factor), with 4 out of 55 species vulnerable for all three factors, 29 for two factors, and 22 for one factor. Six out of ten rodent species endemic to Oaxaca were vulnerable for two or more factors. We found that species with narrow and restricted‐range distributions combined with low adaptive capacity were projected to be particularly vulnerable.Main conclusionsBy including species‐specific trait information in climate exposure assessments, researchers can contextualize and enhance their understanding about how climate change is likely to affect individual taxa in an area of interest. As such, studies like this one provide more relevant threat assessment information than exposure analyses alone and serve as a starting point for considering how climatic changes interact with an array of other variables to affect native species across their range.

Assessment of climate change impacts on water balance and hydrological extremes in Bang Pakong-Prachin Buri river basin, Thailand

Among many factors the hydrology of a watershed is mainly influenced by climate and land use change. This study examined the impacts of climate change on water resources and extreme events in the Bang Pakong-Prachin Buri River Basin, Thailand using three different Regional Climate Models (RCMs) ACCESS1-CSIRO-CCAM, CNRM-CM5-CSIRO-CCAM, and MPI-ESM-LR-CSIRO-CCAM under RCP4.5 and RCP8.5 emission scenarios. Soil and Water Assessment Tool (SWAT) was used to simulate the future streamflow and Extreme Value Type I distribution (EVI) was used to analyze the extreme events under projected climate conditions. The result of this study showed an increase in maximum (1.9 °C/3.6 °C) and minimum (1.6 °C/3.3 °C) temperatures under RCP4.5/8.5 at the end of the 21st century. In addition, projected rainfall is expected to decrease up to 6.8% (8.5%) in 2050s and then increase slowly such that the decrement remains 4.2% (11.0%) under RCP4.5 (RCP8.5) at the end of the century. The rainfall pattern is projected to considerably fluctuate, in particular, a shift in long term average annual peak event from September to August is predicted in 2080s under emission scenario RCP4.5 (RCP8.5). On the other hand, the average annual discharge is expected to increase up to 13.5% (2020s) and 7.6% (2050s) under RCP4.5 and RCP8.5 respectively with decreasing trend in low flows and increasing trend in high flows. Further analysis on extreme events; strengthened the results from hydrological modeling with an increase in flow volume for the same return period under changed climate conditions. This raises water resources management issues in the Bang Pakong-Prachin Buri River Basin regarding the frequency of flood and drought events in the future calling for proper policy formulation and implementation.

High Sowing Densities in Rainfed Common Beans (Phaseolus vulgaris L.) in Mexican Semi-Arid Highlands under Future Climate Change

Mexico holds the largest single bean production area in the world that is vulnerable to drought. Using field data and two future climate scenarios (RCP4.5 and RCP8.5) for the period 2020–2039, this study evaluated three common bean (Phaseolus vulgaris L.) cultivars planted under rainfed conditions at different densities in two locations in the north-central Mexican semi-arid temperate highlands. The sowing densities were 90,000, 145,000, and 260,000 plants ha−1 established in single rows (SR), three rows (3R), and six rows (6R), respectively. The climate change scenarios were derived from an assembly model integrating 11 general circulation models (GCM) selected for Mexico with a 30” arc resolution. The baseline climate was for the period 1961–2010. The ALMANACMEX model (USDA-ARS-INIFAP, Temple, USA) was parameterized and evaluated and then re-run using the climate scenarios. Beans planted at 6R showed the highest increase in seed yield in both climate scenarios, although the response varied by cultivar and time periods. For the growth habit III cultivars, Flor de Mayo Bajio showed no difference in yield, while Pinto Saltillo, a drought-resistant cultivar, showed increases of 13% to 16% at 6R only until 2033. Growth habit I cultivar Azufrado 2 showed more than 60% increases at 6R in both climate scenarios for the full period 2020–2039. These results suggest that considering the projected climate conditions, high sowing densities may be a viable agronomic option for common bean production under rainfed conditions in semi-arid temperate regions, such as the highlands of Mexico, in the near future; however, the selection of the cultivar is a key element to consider in this regard.

The potential impact of climate change on the transmission risk of tick-borne encephalitis in Hungary

BackgroundImpact of climate change on tick-borne encephalitis (TBE) prevalence in the tick-host enzootic cycle in a given region depends on how the region-specific climate change patterns influence tick population development processes and tick-borne encephalitis virus (TBEV) transmission dynamics involving both systemic and co-feeding transmission routes. Predicting the transmission risk of TBEV in the enzootic cycle with projected climate conditions is essential for planning public health interventions including vaccination programs to mitigate the TBE incidence in the inhabitants and travelers. We have previously developed and validated a mathematical model for retroactive analysis of weather fluctuation on TBE prevalence in Hungary, and we aim to show in this research that this model provides an effective tool for projecting TBEV transmission risk in the enzootic cycle.MethodsUsing the established model of TBEV transmission and the climate predictions of the Vas county in western Hungary in 2021-2050 and 2071-2100, we quantify the risk of TBEV transmission using a series of summative indices - the basic reproduction number, the duration of infestation, the stage-specific tick densities, and the accumulated (tick) infections due to co-feeding transmission. We also measure the significance of co-feeding transmission by observing the cumulative number of new transmissions through the non-systemic transmission route.ResultsThe transmission potential and the risk in the study site are expected to increase along with the increase of the temperature in 2021-2050 and 2071-2100. This increase will be facilitated by the expected extension of the tick questing season and the increase of the numbers of susceptible ticks (larval and nymphal) and the number of infected nymphal ticks co-feeding on the same hosts, leading to compounded increase of infections through the non-systemic transmission.ConclusionsThe developed mathematical model provides an effective tool for predicting TBE prevalence in the tick-host enzootic cycle, by integrating climate projection with emerging knowledge about the region-specific tick ecological and pathogen enzootic processes (through model parametrization fitting to historical data). Model projects increasing co-feeding transmission and prevalence of TBEV in a recognized TBE endemic region, so human risk of TBEV infection is likely increasing unless public health interventions are enhanced.

Response of Seasonal Vegetation Dynamics to Climatic Constraints in Northeastern Burundi

The climate crises in East Africa (EA), particularly in Burundi, have affected vegetation which, in turn, plays a key role in the climate system by modifying the terrestrial water and energy balance. Consequently, it is vital to understand vegetation dynamics and its response to current and projected climate conditions to support the design of climate resilient land management strategies. The objective of this study was to study the dynamics of vegetation cover over the Northeastern Burundi (NEB) in response to climatic constraints. The methodology used consisted of the interpretation of satellite images along with the analysis of data collected through rain-gauge stations. The data sets used include time series composite moderate resolution imaging spectroradiometer (MODIS) normalized difference vegetation index (NDVI) data collected between February 2000 and December 2017; long term (1986-2017) rainfall data acquired from two meteorological stations throughout the Northeastern provinces in Burundi and precipitation and mean temperature data (1986-2017) from Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) and ERA5 Daily aggregates for the study area. The study provides an assessment of the vegetation trends in NEB using the NDVI time series. In addition, regression analysis is applied to assess the relations between NDVI and precipitation, air temperature, potential evapotranspiration, as well as with growing season characteristics (onset, cessation, and length). Results show that the rate in vegetation productivity is persistently gradual between 2000 and 2011 despite fluctuations from the mean position, followed by a lower growth rate over the period 2011-2017. There has been trend variation in precipitation, neither the temperature was constant. The temperature over the region has increased while the precipitation has decreased. The onset of the growing season and air temperature also show a significant influence on seasonal vegetation dynamics in the region. Drought-induced plant stress observed at the onset of the rainy season was the most important contributor to the subsequent less greening of vegetation especially over the area near the northern lakes.

Satellite Remote Sensing of Precipitation and the Terrestrial Water Cycle in a Changing Climate

The water cycle is the most essential supporting physical mechanism ensuring the existence of life on Earth. Its components encompass the atmosphere, land, and oceans. The cycle is composed of evaporation, evapotranspiration, sublimation, water vapor transport, condensation, precipitation, runoff, infiltration and percolation, groundwater flow, and plant uptake. For a correct closure of the global water cycle, observations are needed of all these processes with a global perspective. In particular, precipitation requires continuous monitoring, as it is the most important component of the cycle, especially under changing climatic conditions. Passive and active sensors on board meteorological and environmental satellites now make reasonably complete data available that allow better measurements of precipitation to be made from space, in order to improve our understanding of the cycle’s acceleration/deceleration under current and projected climate conditions. The article aims to draw an up-to-date picture of the current status of observations of precipitation from space, with an outlook to the near future of the satellite constellation, modeling applications, and water resource management.