High Climatic Risk Research Articles

Effect of low climate impact vs. high climate impact inhalers for patients with asthma and COPD-a nationwide cohort analysis

BackgroundChronic obstructive pulmonary disease (COPD) and asthma can be treated with inhaled corticosteroids (ICS) delivered by low climate impact inhalers (dry powder inhalers) or high climate impact inhalers (pressurized metered-dose inhalers containing potent greenhouse gasses). ICS delivered with greenhouse gasses is prescribed ubiquitously and frequent despite limited evidence of superior effect. Our aim was to examine the beneficial and harmful events of ICS delivered by low and high climate impact inhalers in patients with asthma and COPD.MethodsNationwide retrospective cohort study of Danish outpatients with asthma and COPD treated with ICS delivered by low and high climate impact inhalers. Patients were propensity score matched by the following variables; age, gender, tobacco exposure, exacerbations, dyspnoea, body mass index, pulmonary function, ICS dose and entry year. The primary outcome was a composite of hospitalisation with exacerbations and all-cause mortality analysed by Cox proportional hazards regression.ResultsOf the 10,947 patients with asthma and COPD who collected ICS by low or high climate impact inhalers, 2,535 + 2,535 patients were propensity score matched to form the population for the primary analysis. We found no association between high climate impact inhalers and risk of exacerbations requiring hospitalization and all-cause mortality (HR 1.02, CI 0.92–1.12, p = 0.77), nor on pneumonia, exacerbations requiring hospitalization, all-cause mortality, or all-cause admissions. Delivery with high climate impact inhalers was associated with a slightly increased risk of exacerbations not requiring hospitalization (HR 1.10, CI 1.01–1.21, p = 0.03). Even with low lung function there was no sign of a superior effect of high climate impact inhalers.ConclusionLow climate impact inhalers were not inferior to high climate impact inhalers for any risk analysed in patients with asthma and COPD.

Archetypes of aquaculture development across 150 countries

In this study we compile and integrate data on 42 indicators to examine the social, economic, governance and environmental conditions shaping aquaculture development across 150 countries, including the top 100 aquaculture producing countries. We apply cluster analysis to identify social-ecological archetypes of aquaculture development across these indicators. We also calculate the percentage of global aquaculture production within the quartile ranges of 15 indicators of singular relevance for development. This shows how much aquaculture production is taking place in countries performing low or high on key indices. For example, we show that 85% of global aquaculture production is taking place in countries with the highest or high climate risk, 74% in countries with the lowest or low environmental performance scores, and 90% in countries with the highest or high food supply variability. Our cluster analysis identifies four distinct archetypes driven by the 42 country-level indicators, which includes: climate risk, inland water area, coastal population, seafood consumption, trade balance, governance indices and environmental performance. We characterize the four archetypes as: Archetype 1 - Emerging aquaculture producers, Archetype 2 - Limited aquatic food engagement, Archetype 3 - Developing economy aquaculture producers, Archetype 4 - Wealthy economy aquaculture producers. We discuss this complexity of factors driving each archetype with country specific examples, as well as the utility of integrated social-ecological analysis for both continued aquaculture research and development practice.

Seaport adaptation and capacity investments under inter-port competition and climate-change uncertainty

Climate-related disasters are causing increasing damage to seaports, necessitating investment in climate-change adaptation to enhance resilience. In addition, seaports must invest in capacity to meet the growing maritime demand. Given that the two types of investments are interdependent, we develop a game-theoretic model to determine the strategic investments a seaport should make in adaptation and capacity, considering inter-port competition. We consider three cases: profit-maximizing seaports, welfare-maximizing seaports, and first-best outcome. We show that a seaport facing higher climate risk invests less in capacity but do not necessarily invests more in adaptation. In addition, a seaport invests more in capacity and adaptation when its competitor faces a growing climate risk. Interestingly, given a high climate risk, inter-port competition leads to underinvestment in both capacity and adaptation. Lastly, our case study reveals that the most detrimental scenario for a port arises when its competitor adapts to changing climate while it does not.

Corporate Climate Risk: Measurements and Responses

Abstract This paper conducts a textual analysis of earnings call transcripts to quantify climate risk exposure at the firm level. We construct dictionaries that measure physical and transition climate risks separately and identify firms that proactively respond to climate risks. Our validation analysis shows that our measures capture firm-level variations in respective climate risk exposure. Firms facing high transition risk, especially those that do not proactively respond, have been valued at a discount in recent years as aggregate investor attention to climate-related issues has been increasing. We document differences in how firms respond through investment, green innovation, and employment when facing high climate risk exposure.

Vapor pressure deficit drives the mortality of understorey woody plants during drought recovery in the Atlantic Forest

AbstractQuestionDrought‐induced tree mortality has been documented in forests worldwide but the mechanisms related to drought recovery are still poorly understood. To better predict forest trajectories under future climate scenarios, it is essential to disentangle physiological mechanisms underlying plant mortality caused by El Niño droughts. Here, we assessed how vegetation structure, vapor pressure deficit (VPD), and functional traits interact to mediate tree mortality after a severe drought in a tropical forest.LocationMata das Flores State Park, an Atlantic Forest fragment in southeast Brazil.MethodsWe established 20 permanent plots with contrasting vegetation structure and topography. In each plot, we measured tree abundance and diameter at breast height (DBH) of every woody plant (1–10 cm diameter) at the end of the drought, and two years after the break of drought, to calculate mortality rates during drought recovery. Hydraulic (e.g., maximum stomatal conductance to water vapor, stomatal density, etc.) and economic traits (specific leaf area, wood density, etc.) were measured on the 10 most abundant species. We also measured local air temperature and air humidity using HOBO dataloggers in each plot to calculate the VPD.ResultsThe studied Atlantic Forest understorey did not recover from the 2014–2016 drought, in terms of tree mortality. Lower VPD, driven by big trees in the valley, protected understorey plants with acquisitive economic attributes and conservative hydraulic attributes against mortality. On the other hand, higher VPD, driven by smaller trees and higher stem density on the ridge and slope, increased the mortality of understorey plants with acquisitive attributes.ConclusionRidges represent the most important fraction of the Atlantic Forest and our results suggest this type of forest is at high climate risk due to global change. Altogether, our results highlight that valleys are microclimate refuges for understorey plants and might help mitigate drought impacts in tropical forest under forecasted climate changes.

Where women in agri-food systems are at highest climate risk: a methodology for mapping climate–agriculture–gender inequality hotspots

Climate change poses a greater threat for more exposed and vulnerable countries, communities and social groups. People whose livelihood depends on the agriculture and food sector, especially in low- and middle-income countries (LMICs), face significant risk. In contexts with gendered roles in agri-food systems or where structural constraints to gender equality underlie unequal access to resources and services and constrain women’s agency, local climate hazards and stressors, such as droughts, floods, or shortened crop-growing seasons, tend to negatively affect women more than men and women’s adaptive capacities tend to be more restrained than men’s. Transformation toward just and sustainable agri-food systems in the face of climate change will not only depend on reducing but also on averting aggravated gender inequality in agri-food systems. In this paper, we developed and applied an accessible and versatile methodology to identify and map localities where climate change poses high risk especially for women in agri-food systems because of gendered exposure and vulnerability. We label these localities climate-agriculture-gender inequality hotspots. Applying our methodology to LMICs reveals that the countries at highest risk are majorly situated in Africa and Asia. Applying our methodology for agricultural activity-specific hotspot subnational areas to four focus countries, Mali, Zambia, Pakistan and Bangladesh, for instance, identifies a cluster of districts in Dhaka and Mymensingh divisions in Bangladesh as a hotspot for rice. The relevance and urgency of identifying localities where climate change hits agri-food systems hardest and is likely to negatively affect population groups or sectors that are particularly vulnerable is increasingly acknowledged in the literature and, in the spirit of leaving no one behind, in climate and development policy arenas. Hotspot maps can guide the allocation of scarce resources to most-at-risk populations. The climate-agriculture-gender inequality hotspot maps show where women involved in agri-food systems are at high climate risk while signaling that reducing this risk requires addressing the structural barriers to gender equality.

Probabilistic climate risk assessment in rainfed wheat yield: Copula approach using water requirement satisfaction index

The trend of population growth and the consequent need to increase agricultural production in order to provide for the necessary food is critical topic nowadays. To account for the risks and damage caused by changes in weather and climate constrains, it is important to know how these changes affect the agricultural productivity. Wheat is the world's most widely grown crop and is directly related to worldwide food security issues. As a result, it has always been of interest to researchers as a strategic crop. In this study, the correlation of the Water Requirement Satisfaction Index in six growing periods of rainfed wheat with its yield was examined and found that the highest correlation is seen over the entire growing season. Based on statistical distributions and copula functions, the sensitivity and rainfed wheat yield to the Water Requirement Satisfaction Index was examined. Clayton Copula was selected based on AIC and RMSE evaluation indices. The probability of having crop losses is around 50%, in general. The results showed that the yield risk of rainfed wheat in the Tabriz region drops to 46% under low climatic risk conditions and reaches to 98% under medium and high climate risk conditions. The results allow farmers and stakeholders to better plan and manage food security by knowing the changes in rainfed wheat yield depending on weather conditions. By using different options under different conditions such as wet events, it is also possible to work towards higher yield amounts of rainfed wheat and other rainfed crops.

Climate Risk, Stock Crash Risk, and Greenhouse Gas Emission Trading Scheme: Evidence From Korea

This study examines the relationship between climate risk and stock crash risk and the moderating effect of greenhouse gas emission trading scheme (ETS). Numerous studies have tested stock price crash risk measured by the negative skewness of return distributions in the areas of internal governance mechanism. While interest in environmental performance for sustainable growth of firms has increased, there are no studies on the effect of climate risk on stock crash risk. Thus, we find that climate risk (a firm’s greenhouse gas emissions and energy consumption) increases stock crash risk, and the positive effect of climate risk on stock crash risk is weakened after introduction of the emission trading scheme. This study theoretically extends the literature on the empirical determinants of stock crash risk, and practically provides investors with proven information about whether climate risk is worth considering during investment decisions. Furthermore, at the level of government policy, we can suggest that a monitoring system is needed to mitigate potential information asymmetry problems in firm with high climate risk.

Climate risk exposure and the cross-section of Chinese stock returns

This paper examines the role of climate risk exposure in the cross-sectional pricing of individual stocks in China. We find a premium of low climate risk exposure: stocks with low climate risk exposure significantly outperform those with high climate risk exposure by 0.83% to 0.90% per month in the future, on a risk-adjusted basis. Results of Fama-MacBeth regressions show that the premium of low climate risk exposure remains after controlling for well-known pricing factors. Moreover, a range of alternative settings confirms that the premium is extremely robust. Finally, climate risk exposure is a combination of pricing factors such as profitability and investment, which provides potential explanations for our results. Our study documents the importance of climate risk in cross-sectional pricing in the Chinese stock market.

Attributable factors for climate change adaptation among urban informal settlers of a least developed country, Bhutan

With a fragile mountain ecosystem and being a least developed country, Bhutan is the most vulnerable to climate change with a serious impact on the environment and people, especially to poor informal settlers in urban areas. Therefore, the present study intends to evaluate the vulnerability and adaptation strategies of the urban poor of Thimphu, Bhutan by collecting primary data using a pre-tested questionnaire from 299 households of the slum dwellers distributed in three gewogs, namely Kawang, Mewang and Chang. The questionnaire contained questions on general household information, climate change, and associated adaptation strategies as per the framing of the crisis among the dwellers. The result revealed that the meteorological observation of climatic parameters matched the perception of the informal dwellers. Moreover, dwellers of informal settlements had higher climate risk with low adaptive capacity. Current adaptation strategies such as assistance provided and received, credit support obtained, economizing water usage during scarcity, and allowing extraction of resources from the forest were extended during crises. The logit model resulted that household characteristics, such as family size, family education, and age of the head of household were major demographic characteristics along with assets propelling adaptation measures. Therefore, urban planning should orient for better education and income generating programs for the dwellers besides making them aware of the economizing of resources. Improvement in public services will further strengthen the dwellers with enhanced adaptive capacity.

Climate change risk assessment for ski areas in China

The successful bid for the 2022 Winter Olympics has provided a strong impetus for the development of China's ski industry. Ski areas have sprung up throughout the country, even in the low latitudes south of 30°N. However, ski tourism is extremely susceptible to weather and climate conditions. In the context of global warming, it has become important to assess the climate reliability of ski areas. Therefore, this study demonstrates a novel approach to assessing the ski tourism sector's climate risks, which can be easily applied in other markets catering to the same industry. Using the random forest regression model based on climate projections and survey data, we projected the ski season start dates, end dates and season lengths of 694 existing ski areas in China under three emission scenarios (RCP2.6, RCP4.5 and RCP8.5). Climate projections, including air temperature, snowfall, rainfall, wind speed and air humidity, were the ensemble means from five climate models. Results indicate that ski areas in China may have later start dates, earlier end dates and shorter ski seasons before 2099. By the 2090s, under RCP2.6, RCP4.5 and RCP8.5, 20% (139), 28% (195) and 35% (245) of ski areas are projected to be at high climate risk (ski season less than 60 d), respectively, while 28% (197), 23% (157) and 8% (56) of ski areas are at low climate risk (ski season with at least 100 d), respectively. The climate risks are ranked from the highest to lowest in East, Central, Southwest, North, Northwest and Northeast China. Furthermore, the ski tourism sector in the latitudes south of 40°N is exposed to much higher climate risks than in areas north of 40°N. Therefore, climatic reliability should be carefully considered before establishing or expanding ski areas to avoid unnecessary resource waste and ecological damage, as well as to promote sustainable development in mountain areas.

Climate risk vulnerability assessment on the production of heirloom rice (Oryza sativa L.) and Arabica coffee (Coffea arabica L.) in Mountain Province, Philippines

Climate change has brought negative and adverse impacts to agricultural production in the Cordillera Administrative Region, including two of the most important agricultural crops, namely, Arabica coffee and heirloom rice. This study was conducted to assess the climate risk vulnerability on the production of these two agricultural products in the municipalities of Mountain Province, Philippines. The climate risk vulnerability was assessed based on the three general and most widely used climate impact factors as recommended by the Intergovernmental Panel on Climate Change (IPCC), namely, exposure to hazard, sensitivity, and adaptive capacity. The results show, based on the combined indices estimated for each of the three general factors and expected changes in temperature and precipitation as projected by IPCC, that there is high climate risk vulnerability of the two crops in the municipalities particularly in areas where there is high potential exposure to hazards, low climate suitability of key crops in the future, and low adaptive capacity. Findings from the climate risk vulnerability analysis (CRVA) developed in the study demonstrate that it, as described in this paper, can serve as a meaningful reference to inform and guide decision-makers from concerned government agencies and the private sector in crafting policies and potential interventions in highly vulnerable areas whose climate risk vulnerability can be estimated and determined using CRVA. It is recommended that the CRVA described in this paper be made part of the tools and potential guides used by the Department of Agriculture to help mainstream climate change adaptation and mitigation strategies.

Are Mediterranean marine threatened species at high risk by climate change?

Rapid anthropogenic climate change is driving threatened biodiversity one step closer to extinction. Effects on native biodiversity are determined by an interplay between species' exposure to climate change and their specific ecological and life-history characteristics that render them even more susceptible. Impacts on biodiversity have already been reported, however, a systematic risk evaluation of threatened marine populations is lacking. Here, we employ a trait-based approach to assess the risk of 90 threatened marine Mediterranean species to climate change, combining species' exposure to increased sea temperature and intrinsic vulnerability. One-quarter of the threatened marine biodiversity of the Mediterranean Sea is predicted to be under elevated levels of climate risk, with various traits identified as key vulnerability traits. High-risk taxa including sea turtles, marine mammals, Anthozoa and Chondrichthyes are highlighted. Climate risk, vulnerability and exposure hotspots are distributed along the Western Mediterranean, Alboran, Aegean, and Adriatic Seas. At each Mediterranean marine ecoregion, 21%-31% of their threatened species have high climate risk. All Mediterranean marine protected areas host threatened species with high risk to climate change, with 90% having a minimum of 4 up to 19 species of high climate risk, making the objective of a climate-smart conservation strategy a crucial task for immediate planning and action. Our findings aspire to offer new insights for systematic, spatially strategic planning and prioritization of vulnerable marine life in the face of accelerating climate change.

Climate adaptation in Coastal Virginia: an analysis of existing policies and main stakeholders

ABSTRACT The impacts of climate change have sparked policy responses at different governance levels. Studying the central adaptation policies and understanding the interactions and complexities of governmental and non-governmental stakeholders is essential in guiding policymakers at different levels of government to formulate policies and make investment decisions. With strategic and economic significance on the national level, Coastal Virginia has one of the highest rates of sea-level rise in the United States, instigating intensified and more frequent climate hazards such as flooding and storms. This paper strives to characterize the status of adaptation policymaking in this region through a novel keyword analysis method and a thematic analysis of interviews with the main adaptation decision-makers and stakeholders. We identify the central adaptation policies and programmes at the local, regional, state, and federal level, as well as the major relevant players. This provides a comprehensible narrative of adaptation policymaking, which could be exploited to further analyze governance gaps and adaptation challenges. The approach and methodologies of this research could be implemented in similar studies for other areas of the U.S. that are at high climate risk, possibly facilitating an informed national adaptation policy, long overdue by the federal government. The research is also relevant for other jurisdictions at risk of sea-level rise. Key policy insights Coastal adaptation policymaking in Virginia has been a bottom-up and fragmented process initiated by most affected localities, exhibiting the importance of local initiatives in higher-level adaptation policies. The long-lasting impacts of 100 Resilient cities and Dutch Dialogues in the City of Norfolk highlight the value of fostering cross-geographic coordination and capacity-building programmes, confirming the importance of informal policy networks in learning and innovation for adaptation. There is a vast difference among localities in adaptation planning and implementation, creating the need for coordinating state leadership. Adaptation policymaking in Virginia has been influenced by political cycles with priorities drastically altered by each administration change, introducing significant uncertainty for continuation of policies. National policies and programmes, such as the Inflation Reduction Act of 2022, can significantly affect local-level policies and decision-making.

Intensity and number of thinning operations affect the response of Eucalyptus grandis to water availability and extreme drought events

Climate change has induced an increase in the frequency and intensity of droughts and heat waves, reducing growth and increasing the mortality risk of both natural and planted forests. Management practices are expected to affect the capacity of stands to tolerate these new and fluctuating environmental conditions. Particularly, the effect of thinning on growth and mortality responses to climatic variation is highly variable among species and environmental conditions, and very few studies have been carried out in broad-leaved species. The objectives of this study were to assess the effect of forest thinning on (1) the growth sensitivity of planted Eucalyptus grandis to typical interannual variation in water availability and (2) its response to extreme drought events. We analyzed data collected in the period 1999–2016 from three thinning trials installed in sites with normal growth conditions of the species in a subtropical, humid and warm region of South America (Mesopotamia region, Argentina), where it is the most planted Eucalyptus species. Different intensities (final densities between 300 and 1250 plants/ha) and modalities (single- versus two-stage) of thinning operations were applied in each trial. First, we used a hierarchical linear model to relate basal area increment to water balance, and from this analysis we obtained the mean growth and sensitivity to water balance at individual, treatment and site levels. Results at the treatment level show that the mean growth of E. grandis increases with thinning intensity while its sensitivity to water balance decreases, consistently across all sites. At the individual level, using Hegyi’s intraspecific competition index we observed that higher competition induces lower mean growth and higher sensitivity to water balance, regardless of the number of thinning stages. Second, we selected an extreme drought event at each site and computed resistance and resilience indices, as well as the probability of tree mortality associated with the event. Within the single-stage thinning treatments, those with the highest intensity showed the highest resistance (i.e. the lowest growth decrease during the drought event), while stand density did not affect their resilience (i.e. growth recovery after the drought event). The effect of thinning intensity on the probability of death due to the drought event was not conclusive. On the other hand, the two-stage treatments presented much higher resistance and resilience values than the other treatments, suggesting that this modality of treatment could be effective in improving the adaptability of E. grandis to extreme drought events. We conclude that high-intensity thinning interventions could increase the ability of this species to cope with climate change and benefit solid wood production, where the associated decrease in stand-level growth may be compensated by an increase in the individual-tree growth. For other industrial purposes, where final stand-level production is a key driver, medium intensity two-stage thinning is recommended, in particular when genetic materials selected for drought resistance are not available and there is high climatic risk.

Do green growth and technological innovation matter to infrastructure investments in the era of climate change? Global evidence

ABSTRACT This study investigates the nexus between green growth, technological innovations, and infrastructure investment trends, through an international investigation of 56 countries for the period of 2000–2020. Based on the Environmental Impact by Population, Affluence and Technology (IPAT) and Stochastic Impacts by Regression on Population, Affluence and Technology (STIRPAT) frameworks, the study looks at the nexus between infrastructure investments, green growth, and technological innovations in the era of climate change. We find that increases in global carbon emissions are associated with higher infrastructure investment needs for the sustainable development of the world’s economy. Besides global infrastructure investments for sustainable development goals (SDGs), the economic costs of climate change are also reflected in technological innovations across countries and sectors. With higher investments in technological innovations such as low-carbon infrastructure and energy technologies, we highlight the roles of environment-oriented R&D and taxes in our global sample. The findings are validated through utilising a set of econometric techniques and are particularly crucial to emerging economies, and pollutingeconomies with high climate risk exposure. SDGs. Our study provides a formal empirical investigation of climate change, investments in infrastructure, and green growth. We also provide critical policy implications, future directions, and agendas in sustainable green finance and climate economics.

International political uncertainty and climate risk in the stock market

This paper investigates how political uncertainty interacts with an international firm’s climate risk in affecting the stock market. Using firms from 34 countries, we employ the presidential election events in the United States and those in other countries that have stock markets as a proxy for political uncertainty. We find that the global stock markets respond significantly to political uncertainty induced by the U.S. presidential elections but not to elections in their home countries. Although we observe a marginally significant change in stock return for firms with different levels of climate risk during periods of political uncertainty, we find that firms with high climate risk experience high return volatility and return correlation amid uncertainty associated with U.S. presidential elections. The results are consistent with literature that indicates U.S. presidential election is an indicator of international political uncertainty. Further, we present new evidence on how political uncertainty affects the riskiness of firms with high exposure to climate risk.

Projected stream fish community risk to climate impacts in the Northeastern and Midwestern United States

Climate change is expected to alter stream fish habitat potentially leading to changes in the composition and distribution of fish communities. In the Northeastern and Midwestern United States we identified the distribution and characteristics of those fish communities most and least at risk of experiencing changes in climate which deviate from the climate they are associated with. We classified stream fish communities based on a suite of climate and environmental variables with multivariate regression trees under both recent and future conditions based on eight climate models. Our findings showed that some areas, such as the majority of the Illinois, Wisconsin, and Iowa), have high levels of risk of change in stream class, while much of Kentucky, West Virginia, Virginia, Pennsylvania, Eastern Ohio, Southern Michigan, and the Atlantic Coast are at relatively low risk. Stream class shifts ranged from over 75% of segments lost (associated with cooler temperatures) to gains of over 40% (associated with warmer temperatures). Common warmwater species such as green sunfish (Lepomis cyanellus), bluegill (Lepomis macrochirus) and largemouth bass (Micropterus salmoides) are expected to have the largest net gains in associated stream classes, while species associated with cooler streams such as Southern redbelly dace (Chrosomus erythrogaster), slimy sculpin (Cottus cognatus), and Eastern blacknose dace (Rhinichthys atratulus) were expected to experience the largest proportional losses. By pairing our climate risk predictions with other stressors such anthropogenic land use, habitat fragmentation, and water quality impairment, we identified opportunities for preservation (low risk due to all threats), restoration (low risk due to climate, high risk due to other stressors), and adaptation (high climate risk with low risk from other stressors). Understanding which communities are at risk due to climate change will aid in developing adaptation strategies to help sustain them in the future.

Transitional wave climate regions on continental and polar coasts in a warming world

Wave climate is a primary driver of coastal risk, yet how climate change is altering wave climate is not fully understood. Here we identify transitional wave climate regions, coastlines with a future change in the occurrence frequency of a wave climate, with most of the regions located in south-western and eastern ocean basins. Analysis of the spatio-temporal changes in the atmosphere-driven major wave climates (the easterlies, southerlies and westerlies) under 2 emission scenarios for 2075–2099 and 2081–2099 shows increases in frequency from 5 to 20% for the easterly and southerly wave climates. The projected changes in these regions, in addition to sea-level rise and changes in storminess, can modify the general patterns of the prevailing wave climates and severely alter their coastal risks. Consequently, transitional wave climate regions should be recognized as areas of high coastal climate risk that require focus for adaptation in the near term. Changes in wave climate can pose substantial risk to coastal areas. Here transitional wave climate regions—areas where a wave climate will increase its frequency of occurrence—are identified and classified with implications for understanding future coastal risk.

Forage sorghum production under rainfed farming in sites with and without climate restriction for maize cultivation

Forage sorghum is a crop that can be planted in semiarid regions, due to its greater adaptability to dry climate environments, and can replace maize in these regions, which are often unsuitable for its production. Thus, the objective of the study was to evaluate the structural, morphological and nutritional characteristics of 23 sorghum hybrids forage cultivated in rainfed conditions, planted in different climate conditions, comparing the hybrids, in order to determine what produces the best in the climatic conditions of the explored region, and also to indicate whether this crop can be planted as a replacement for maize in environments not suitable for planting it. The research was conducted in climate BSh in the Municipality of Alvorada do Gurgueia, and climate Aw in the Municipality of Bom Jesus, both in the state of Piauí from 2014 to 2015. Each trial consisted of 20 experimental forage sorghum hybrids [Sorghum bicolor (L.) Moench], and three commercial hybrids. A randomized block design was used, with three replications in a factorial scheme (2 × 23). The growth characteristics determined were hybrid × climate interaction for the variables plant height, lodging and leaf/stem ratio. For the variable number of tillers, there was a significant difference only between hybrids. There was no difference between hybrids only for the lodging variable of climate Aw. The other variables showed a difference in all hybrids evaluated. There was an interaction for production of dead matter and total dry forage mass between the different environments and hybrids evaluated. For leaf production, there was an effect only for the different environments. For the chemical characteristics, there was an interaction for all variables analyzed between the different environments and hybrids evaluated. The semi-arid region of the State of Piauí, climate BSh which presents a high climatic risk for maize cultivation, proved to be favorable for forage sorghum production. The forage sorghum also presented agronomic characteristics similar to those found in semi humid climate Aw, a favorable region for maize cultivation. In addition, the tested hybrids showed good chemical characteristics, so the BSh climate has great exploratory potential for the cultivation of forage sorghum.