Integrating pests and pathogens into the climate change/food security debate
TL;DR: More mechanistic inclusion of pests and pathogen effects in crop models would lead to more realistic predictions of crop production on a regional scale and thereby assist in the development of more robust regional food security policies.
Abstract: While many studies have demonstrated the sensitivities of plants and of crop yield to a changing climate, a major challenge for the agricultural research community is to relate these findings to the broader societal concern with food security. This paper reviews the direct effects of climate on both crop growth and yield and on plant pests and pathogens and the interactions that may occur between crops, pests, and pathogens under changed climate. Finally, we consider the contribution that better understanding of the roles of pests and pathogens in crop production systems might make to enhanced food security. Evidence for the measured climate change on crops and their associated pests and pathogens is starting to be documented. Globally atmospheric [CO(2)] has increased, and in northern latitudes mean temperature at many locations has increased by about 1.0-1.4 degrees C with accompanying changes in pest and pathogen incidence and to farming practices. Many pests and pathogens exhibit considerable capacity for generating, recombining, and selecting fit combinations of variants in key pathogenicity, fitness, and aggressiveness traits that there is little doubt that any new opportunities resulting from climate change will be exploited by them. However, the interactions between crops and pests and pathogens are complex and poorly understood in the context of climate change. More mechanistic inclusion of pests and pathogen effects in crop models would lead to more realistic predictions of crop production on a regional scale and thereby assist in the development of more robust regional food security policies.
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TL;DR: The most likely changes in crop species and varieties in Finland and the pest and pathogen species that are most likely to create production problems as a result of climate change during this century are identified.
Abstract: A longer growing season and higher accumulated effective temperature sum (ETS) will improve crop production potential in Finland. The production potential of new or at present underutilised crops (e.g. maize (Zea mays L.), oilseed rape (Brassica napus L.), lucerne (Medicago sativa L.)) will improve and it will be possible to grow more productive varieties of the currently grown crops (spring wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), oats (Avena sativa L.)). Also cultivation of autumn sown crops could increase if winters become milder and shorter, promoting overwintering success. Climatic conditions may on the other hand become restrictive in many ways. For example, early season droughts could intensify because of higher temperatures and consequent higher evaporation rates. Current low winter temperatures and short growing season help restrict the development and spread of pests and pathogens, but this could change in the future. Longer growing seasons, warmer autumns and milder winters may initiate new problems with higher occurrences of weeds, pests and pathogens, including new types of viruses and virus vectors. Anoxia of overwintering crops caused by ice encasement, and physical damage caused by freezing and melting of water over the fields may also increase. In this study we identify the most likely changes in crop species and varieties in Finland and the pest and pathogen species that are most likely to create production problems as a result of climate change during this century.
86 citations
Cites background from "Integrating pests and pathogens int..."
...Changing climate will also favour powdery mildew (Blumeria graminis (DC.) Speer) infections of winter wheat and barley (Gregory et al. 2009)....
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...Genes active against diseases at low (10 °C) temperatures can be turned off at high (25 °C) temperatures (Gregory et al. 2009)....
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TL;DR: It is shown that high cyanogen levels confer important agronomic advantages, but also impose costs and constraints that can only be understood when biology is coupled with analysis of social, cultural and economic factors.
Abstract: Chemical ecology provides unique perspectives for managing plant/human interactions to achieve food security. Allelochemicals function as chemical defences of crop plants, enhancing yields. While ingested allelochemicals can confer health benefits to humans, at higher concentrations they are often toxic. The delicate balance between their positive and negative effects in crop plants is influenced by many factors. Some of these—how environment affects optimal levels of defence, how metabolic interactions with nutrients affect toxicity of ingested allelochemicals—are the province of chemical ecology. These biological factors, however, interact with social factors, and neither can be studied independently. Chemical ecologists must work together with social scientists to understand the overall system. Here, we illustrate such an integrative approach, analysing the interactions between people and the major tropical crop manioc, which contains cyanogenic glucosides. Polymorphism for cyanogen levels in manioc facilitates analysis of how costs and benefits of crop defences vary among social systems. We first show how people/manioc interactions diversified in this crop’s Amazonian homeland, then turn to the remarkable cultural adaptations of African farmers since manioc’s introduction 400 years ago. Finally, we evaluate new coevolutionary challenges in parts of Africa where people are still unfamiliar with a potentially dangerous crop. Current environmental and social catastrophes have restricted farmers’ options, resulting in acute problems in health of humans and ecosystems. We show that high cyanogen levels confer important agronomic advantages, but also impose costs and constraints that can only be understood when biology is coupled with analysis of social, cultural and economic factors. Detoxifying manioc technologically requires know-how, time, water and other resources. Detoxifying residual dietary cyanogens metabolically depends on being able to grow, or to buy, the nutrients required for detoxification, primarily sulphur-rich proteins. Solutions that appear adaptive today may not be in the future, as changing climate, rising atmospheric CO2 levels and decreased access to fertilizers affect productivity of crops and the nutrient and allelochemical composition of the foods they are used to produce.
85 citations
Cites background from "Integrating pests and pathogens int..."
...Protein levels in wheat, barley and rice are expected to be 10–15% lower by 2030 as a direct result of increasing CO2 (Erbs et al. 2010; Gregory et al. 2009; Taub et al. 2008; Wieser et al. 2008), and, indeed, may have already decreased in the past 50 years (Taub et al. 2008)....
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...Economic and social factors, agricultural practices, and changing environments and climates can all affect the durability of food-production systems (Gregory et al. 2009)....
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TL;DR: This review discusses how network concepts can be applied in plant pathology from the molecular to the landscape and global level and provides an example of an emerging pathosystem (Phytophthora ramorum) where a theoretical network approach has proven particularly fruitful in analyzing the spread of disease in the UK plant trade.
Abstract: There is increasing use of networks in ecology and epidemiology, but still relatively little application in phytopathology. Networks are sets of elements (nodes) connected in various ways by links (edges). Network analysis aims to understand system dynamics and outcomes in relation to network characteristics. Many existing natural, social, and technological networks have been shown to have small-world (local connectivity with short-cuts) and scale-free (presence of super-connected nodes) properties. In this review, we discuss how network concepts can be applied in plant pathology from the molecular to the landscape and global level. Wherever disease spread occurs not just because of passive/natural dispersion but also due to artificial movements, it makes sense to superimpose realistic models of the trade in plants on spatially explicit models of epidemic development. We provide an example of an emerging pathosystem (Phytophthora ramorum) where a theoretical network approach has proven particularly fruitful in analyzing the spread of disease in the UK plant trade. These studies can help in assessing the future threat posed by similar emerging pathogens. Networks have much potential in plant epidemiology and should become part of the standard curriculum.
84 citations
Cites background from "Integrating pests and pathogens int..."
...For many countries, the growing security risk posed by plant pathogens is likely to be exacerbated by climate changes (41,115)....
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TL;DR: The authors provides an overview on research approaches and challenges in climate change biology with respect to plant pathogens, insect pests and weeds (collectively termed "pests" here), and summarizes the suggestions of researchers about how to conceptualize and prioritize future research strategies.
Abstract: Climate change biology is witnessing a significant quantity of new publications each year, which compromises efforts to keep up-to-date on the rapidly growing body of climate change biology literature. The present paper provides an overview on research approaches and challenges in climate change biology with respect to plant pathogens, insect pests and weeds (collectively termed ‘pests’ here). It also summarizes the suggestions of researchers about how to conceptualize and prioritize future research strategies. Recently published key studies demonstrate that climate change research is qualitatively advancing and that the interactions among environmental and biotic factors which have been found are complex. This complexity hinders attempts to generalize responses of pests to changes in climate. The challenge remains to identify the most significant causal relationships and to separate them from other factors such as crop management practices, which may also influence the observed changes in pest distribution and prevalence in managed ecosystems. In addition, the present overview shows that there are still gaps in many research areas, while other fields have been intensively investigated. For example, the identification of potential benefits in plant protection that may emerge from future climate change has not been explored as extensively as the potential threats. However, encouraging developments can be observed in recent climate change research, for instance the increased number of studies performed under subtropical and tropical climatic conditions, the increased availability of results from multi-factorial field experiments and modelling studies do consider increasingly pest–crop–climate interactions. Further progress can be expected, provided that researchers, sponsors and other stakeholders maintain their interest in climate change biology research.
80 citations
Potsdam Institute for Climate Impact Research1, Karlsruhe Institute of Technology2, International Institute for Applied Systems Analysis3, Comenius University in Bratislava4, Columbia University5, University of Chicago6, Lund University7, University of Birmingham8, University of Natural Resources and Life Sciences, Vienna9, University of Potsdam10, Lamont–Doherty Earth Observatory11
TL;DR: Conservative estimates of the fraction of reported national yield variabilities that can be attributed to weather by state-of-the-art, process-based crop model simulations find that observed weather variations can explain more than 50% of the variability in wheat yields in Australia, Canada, Spain, Hungary, and Romania.
Abstract: Year-to-year variations in crop yields can have major impacts on the livelihoods of subsistence farmers and may trigger significant global price fluctuations, with severe consequences for people in developing countries Fluctuations can be induced by weather conditions, management decisions, weeds, diseases, and pests Although an explicit quantification and deeper understanding of weather-induced crop-yield variability is essential for adaptation strategies, so far it has only been addressed by empirical models Here, we provide conservative estimates of the fraction of reported national yield variabilities that can be attributed to weather by state-of-the-art, process-based crop model simulations We find that observed weather variations can explain more than 50% of the variability in wheat yields in Australia, Canada, Spain, Hungary, and Romania For maize, weather sensitivities exceed 50% in seven countries, including the United States The explained variance exceeds 50% for rice in Japan and South Korea and for soy in Argentina Avoiding water stress by simulating yields assuming full irrigation shows that water limitation is a major driver of the observed variations in most of these countries Identifying the mechanisms leading to crop-yield fluctuations is not only fundamental for dampening fluctuations, but is also important in the context of the debate on the attribution of loss and damage to climate change Since process-based crop models not only account for weather influences on crop yields, but also provide options to represent human-management measures, they could become essential tools for differentiating these drivers, and for exploring options to reduce future yield fluctuations
79 citations
Cites background from "Integrating pests and pathogens int..."
...In addition to weather conditions, the occurrence of weeds, diseases, and pests can result in yield fluctuations [Gregory et al., 2009]....
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References
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01 Jan 2007
TL;DR: The first volume of the IPCC's Fourth Assessment Report as mentioned in this paper was published in 2007 and covers several topics including the extensive range of observations now available for the atmosphere and surface, changes in sea level, assesses the paleoclimatic perspective, climate change causes both natural and anthropogenic, and climate models for projections of global climate.
Abstract: This report is the first volume of the IPCC's Fourth Assessment Report. It covers several topics including the extensive range of observations now available for the atmosphere and surface, changes in sea level, assesses the paleoclimatic perspective, climate change causes both natural and anthropogenic, and climate models for projections of global climate.
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TL;DR: In this paper, the authors set the stage for impact, adaptation, and vulnerability assessment of climate change in the context of sustainable development and equity, and developed and applied scenarios in Climate Change Impact, Adaptation, and Vulnerability Assessment.
Abstract: Summary for policymakers Technical summary Part I. Setting the Stage for Impact, Adaptation, and Vulnerability Assessment: 1. Overview 2. Methods and tools 3. Development and application of scenarios in Climate Change Impact, Adaptation, and Vulnerability Assessment Part II. Sectors and Systems: Impacts, Adaptation, and Vulnerability: 4. Hydrology and water resources 5. Natural and managed ecosystems 6. Coastal zones and marine ecosystems 7. Energy, industry, and settlements 8. Financial services 9. Human health Part III. Regional Analyses: Impacts, Adaptation, and Vulnerability: 10. Africa 11. Asia 12. Australasia 13. Europe 14. Latin America 15. North America 16. Polar regions (Arctic and Antarctic) 17. Small island states Part IV. Global Issues and Synthesis: 18. Adaptation to climate change in the context of sustainable development and equity 19. Synthesis and integration of impacts, adaptation, and vulnerability Index.
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TL;DR: In this paper, the authors present a cross-chapter case study on climate change and sustainability in natural and managed systems and assess key vulnerabilities and the risk from climate change, and assess adaptation practices, options, constraints and capacity.
Abstract: Foreword Preface Introduction Summary for policymakers Technical summary 1. Assessment of observed changes and responses in natural and managed systems 2. New assessment methodologies and the characterisation of future conditions 3. Fresh water resources and their management 4. Ecosystems, their properties, goods and services 5. Food, fibre and forest products 6. Coastal systems and low-lying areas 7. Industry, settlement and society 8. Human health 9. Africa 10. Asia 11. Australia and New Zealand 12. Europe 13. Latin America 14. North America 15. Polar regions (Arctic and Antarctic) 16. Small islands 17. Assessment of adaptation practices, options, constraints and capacity 18. Inter-relationships between adaptation and mitigation 19. Assessing key vulnerabilities and the risk from climate change 20. Perspectives on climate change and sustainability - 811 Cross-chapter case studies Appendix I. Glossary Appendix II. Contributors to the IPCC WGII Fourth Assessment Report Appendix III. Reviewers of the IPCC WGII Fourth Assessment Report Appendix IV. Acronyms and abbreviations Appendix V. Index and database of regional content Index CD-ROM.
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Journal Article•
TL;DR: In this article, the authors present a document, redatto, voted and pubblicato by the Ipcc -Comitato intergovernativo sui cambiamenti climatici - illustra la sintesi delle ricerche svolte su questo tema rilevante.
Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.
4,187 citations