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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01 Jan 2010
TL;DR: SARUA, in partnership with the University of Mauritius, hosted a Southern African Higher Education Leadership Programme to review the present contribution of higher education in southern Africa and to explore opportunities for scaling up existing initiatives so that it can make a meaningful impact on the way the region responds to climate change, adaptation and sustainability as mentioned in this paper.
Abstract: SARUA, in partnership with the University of Mauritius, hosted a Southern African Higher Education Leadership Programme to review the present contribution of higher education in southern Africa and to explore opportunities for scaling up existing initiatives so that it can make a meaningful impact on the way the region responds to climate change, adaptation and sustainability. This leadership dialogue sought to take advantage of increasing the momentum gained, the relationships formed, and the knowledge created by a number of recent initiatives, to explore the nexus between climate change, adaptation and higher education1. The aim of the leadership dialogue was to determine the progress made in regard to integrating climate change into higher education teaching and learning, knowledge production and community engagement.
20 citations
TL;DR: Investigating how increases in temperature (eT) and eCO2 affected the performance of the pea aphid via changes in amino acid concentrations in the model legume, lucerne, identified discrete functional groups of amino acids that underpinned the effects of climate and atmospheric change, in addition to plant genotype, on aphid performance.
Abstract: Global climate and atmospheric change are widely predicted to affect many ecosystems. Herbivorous insects account for 25% of the planet's species so their responses to environmental change are pivotal to how future ecosystems will function. Atmospheric change affects feeding guilds differently, however, with sap-feeding herbivores consistently identified as net beneficiaries of predicted increases in atmospheric carbon dioxide concentrations (eCO2). The mechanistic basis for these effects remains largely unknown, and our understanding about how multiple environmental changes, acting in tandem, shape plant–insect interactions is incomplete.
This study investigated how increases in temperature (eT) and eCO2 affected the performance of the pea aphid (Acyrthosiphon pisum) via changes in amino acid concentrations in the model legume, lucerne (Medicago sativa).
Aphid performance increased under eCO2 at ambient temperatures, whereby aphid fecundity, longevity, colonization success and rm increased by 42%, 30%, 25% and 21%, respectively. eT negated the positive effects of eCO2 on both fecundity and rm, however, and performance was similar to when aphids were reared at ambient CO2.
We identified discrete functional groups of amino acids that underpinned the effects of climate and atmospheric change, in addition to plant genotype, on aphid performance. Effects of eT and eCO2 held true across five M. sativa genotypes, demonstrating the generality of their effects.
Combining this knowledge with amino acid profiles of existing cultivars raises the possibility of predicting future susceptibility to aphids and preventing outbreaks of a global pest. Moreover, environmentally induced changes in the nutritional ecology of aphids have the capacity to change life-history strategies of aphids and their direct and indirect interactions with many other organisms, including mutualists and antagonists.
20 citations
01 Jan 2014
TL;DR: The interaction between pathogens and plants is often strongly determined by weather, which influences infection processes for pathogens as well as determining rates of reproduction of arthropods that vector pathogens.
Abstract: Plant disease causes regular substantial losses to agricultural production, causing famine in some cases, and also damage to natural plant systems. Fungi, oomycetes, bacteria, viruses, nematodes, and other groups can cause plant disease. The interaction between pathogens and plants is often strongly determined by weather. For example, leaf surface moisture is critical to infection for many foliar pathogens. Temperature influences infection processes for pathogens as well as determining rates of reproduction of arthropods that vector pathogens. As weather patterns change, disease risk also changes, requiring that strategies for management be updated to new conditions.
19 citations
TL;DR: Analysis of recent wheat rust epidemics and smallholders’ coping mechanisms in Ethiopia finds continuous varietal development in responding to emerging new rust races and supporting the deployment of newly released resistant varieties could help smallholders in dealing with rust challenges and maintaining improved yields in the rust-prone environments of Ethiopia.
Abstract: Crops are variously susceptible to biotic stresses-something expected to increase under climate change. In the case of staple crops, this potentially undermines household and national food security. We examine recent wheat rust epidemics and smallholders' coping mechanisms in Ethiopia as a case study. Wheat is a major food crop in Ethiopia widely grown by smallholders. In 2010/11 a yellow rust epidemic affected over one-third of the national wheat area. Two waves of nationally representative household level panel data collected for the preceding wheat season (2009/10) and three years after (2013/14) the occurrence of the epidemic allow us to analyze the different coping mechanisms farmers used in response. Apart from using fungicides as ex-post coping mechanism, increasing wheat area under yellow rust resistant varieties, increasing diversity of wheat varieties grown, or a combination of these strategies were the main ex-ante coping mechanisms farmers had taken in reducing the potential effects of rust re-occurrence. Large-scale dis-adoption of highly susceptible varieties and replacement with new, rust resistant varieties was observed subsequent to the 2010/11 epidemic. Multinomial logistic regression models were used to identify the key factors associated with smallholder ex-ante coping strategies. Household characteristics, level of specialization in wheat and access to improved wheat seed were the major factors that explained observed choices. There was 29-41% yield advantage in increasing wheat area to the new, resistant varieties even under normal seasons with minimum rust occurrence in the field. Continuous varietal development in responding to emerging new rust races and supporting the deployment of newly released resistant varieties could help smallholders in dealing with rust challenges and maintaining improved yields in the rust-prone environments of Ethiopia. Given the global importance of both wheat and yellow rust and climate change dynamics study findings have relevance to other regions.
19 citations
01 Jan 2008
TL;DR: The potential impact of future extreme weather events on horticultural crops was evaluated in this paper, where the LARS-WG1, a stochastic weather generator linked with UKCIP02 projections of future climate, was used to estimate the frequency of a defined set of circumstances known to have impact on cropping.
Abstract: The potential impact of future extreme weather events on horticultural crops was evaluated. A review was carried out of the sensitivities of a representative set of crops
to environmental challenges. It confirmed that a range of environmental factors are capable of causing a significant impact on production, either as yield or quality loss.
The most important of these were un-seasonal temperature, water shortage or excess,and storms. Future scenarios were produced by the LARS-WG1, a stochastic weather generator linked with UKCIP02 projections of future climate. For the analyses, 150 years of synthetic weather data were generated for baseline, 2020HI and 2050HI scenarios at defined locations. The output from the weather generator was used in case studies, either to estimate the frequency of a defined set of circumstances known to have impact on cropping, or as inputs to models of crop scheduling or pest phenology or survival. The analyses indicated that episodes of summer drought severe enough to interrupt the continuity of supply of salads and other vegetables will increase while the frequency of autumns with sufficient rainfall to restrict potato lifting will decrease. They also indicated that the scheduling of winter cauliflowers for continuity of supply will require the deployment of varieties with different temperature sensitivities from those in use currently. In the pest insect studies, the number of batches of Agrotis segetum (cutworm) larvae surviving to third instar increased with time, as did the potential number of generations of Plutella xylostella (diamond-back moth) in the growing season, across a range of locations. The study demonstrated the utility of high resolution scenarios in predicting the likelihood of specific weather patterns and their potential effect on horticultural production. Several limitations of the current scenarios and biological models were also identified.
19 citations
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.
32,826 citations
Book•
01 Jul 2001
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.
12,541 citations
Book•
01 Jan 2007
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.
8,465 citations
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