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.
Citations
More filters
TL;DR: Mismatches in phenology between mutually dependent species, resulting from climate change, can have far-reaching consequences throughout an ecosystem at both higher and lower trophic levels, and more research into the complex interactions between species in terrestrial and aquatic ecosystems is necessary to make conclusive predictions of how climate warming may impact the fragile balances within ecosystems in future.
Abstract: Mismatches in phenology between mutually dependent species, resulting from climate change, can have far-reaching consequences throughout an ecosystem at both higher and lower trophic levels. Rising temperatures, due to climate warming, have resulted in advances in development and changes in behaviour of many organisms around the world. However, not all species or phenophases are responding to this increase in temperature at the same rate, thus creating a disruption to previously synchronised interdependent key life-cycle stages. Mismatches have been reported between plants and pollinators, predators and prey, and pests and hosts. Here, we review mismatches between interdependent phenophases at different trophic levels resulting from climate change. We categorized the studies into (1) terrestrial (natural and agricultural) ecosystems, and (2) aquatic (freshwater and marine) ecosystems. As expected, we found reports of ‘winners’ and ‘losers’ in each system, such as earlier emergence of prey enabling partial avoidance of predators, potential reductions in crop yield if herbivore pests emerge before their predators and possible declines in marine biodiversity due to disruption in plankton-fish phenologies. Furthermore, in the marine environment rising temperatures have resulted in synchrony in a previously mismatched prey and predator system, resulting in an abrupt population decline in the prey species. The examples reviewed suggest that more research into the complex interactions between species in terrestrial and aquatic ecosystems is necessary to make conclusive predictions of how climate warming may impact the fragile balances within ecosystems in future.
120 citations
TL;DR: The review pinpoints improving confidence in model prediction by minimizing uncertainty, developing management strategies to reduce overall pathogen fitness, and finding new sources of data to trawl for climate signatures on pathogens as important challenges for future research.
Abstract: Findings on climate change influence on plant pathogens are often inconsistent and context dependent. Knowledge of pathogens affecting agricultural crops and natural plant communities remains fragmented along disciplinary lines. By broadening the perspective beyond agriculture, this review integrates cross-disciplinary knowledge to show that at scales relevant to climate change, accelerated evolution and changing geographic distribution will be the main implications for pathogens. New races may evolve rapidly under elevated temperature and CO2 , as evolutionary forces act on massive pathogen populations boosted by a combination of increased fecundity and infection cycles under favourable microclimate within enlarged canopy. Changing geographic distribution will bring together diverse lineages/genotypes that do not share common ecological niche, potentially increasing pathogen diversity. However, the uncertainty of model predictions and a lack of synthesis of fragmented knowledge remain as major deficiencies in knowledge. The review contends that the failure to consider scale and human intervention through new technology are major sources of uncertainty. Recognizing that improved biophysical models alone will not reduce uncertainty, it proposes a generic framework to increase focus and outlines ways to integrate biophysical elements and technology change with human intervention scenarios to minimize uncertainty. To synthesize knowledge of pathogen biology and life history, the review borrows the concept of 'fitness' from population biology as a comprehensive measure of pathogen strengths and vulnerabilities, and explores the implications of pathogen mode of nutrition to fitness and its interactions with plants suffering chronic abiotic stress under climate change. Current and future disease management options can then be judged for their ability to impair pathogenic and saprophytic fitness. The review pinpoints improving confidence in model prediction by minimizing uncertainty, developing management strategies to reduce overall pathogen fitness, and finding new sources of data to trawl for climate signatures on pathogens as important challenges for future research.
118 citations
TL;DR: While rusts thrive in high-humidity environments, they can also survive in desert habitats, and as a group their environmental tolerance is large, with no conclusive change in their overall prevalence predictable to date.
Abstract: Rust fungi are important components of ecological communities and in ecosystem function. Their unique life strategies as biotrophic pathogens with complicated life cycles could make them vulnerable to global environmental change. While there are gaps in our knowledge, especially in natural plant–rust systems, this review of the exposure of rust fungi to global change parameters revealed that some host–rust relationships would decline under predicted environmental change scenarios, whereas others would either remain unchanged or become more prevalent. Notably, some graminicolous rusts are negatively affected by higher temperatures and increased concentrations of atmospheric CO2. An increase of atmospheric O3 appears to favour rust diseases on trees but not those on grasses. Combined effects of CO2 and O3 are intermediary. The most important global drivers for the geographical and host plant range expansion and prevalence of rusts, however, are global plant trade, host plant genetic homogenization and the regular occurrence of conducive environmental conditions, especially the availability of moisture. However, while rusts thrive in high-humidity environments, they can also survive in desert habitats, and as a group their environmental tolerance is large, with no conclusive change in their overall prevalence predictable to date.
113 citations
TL;DR: This review summarizes the most significant results from the so far existing, but fragmented studies on the potential effects of climate change on wheat pathogens and the diseases they cause and demonstrates that predictions are uncertain and future disease risk trends must be differentiated on a geographic and time scale.
Abstract: This review summarizes the most significant results from the so far existing, but fragmented studies on the potential effects of climate change on wheat pathogens and the diseases they cause. The analysis demonstrates that predictions are uncertain and future disease risk trends must be differentiated on a geographic and time scale. For example, disease incidence of Fusarium head blight in the United Kingdom might increase middle of this century, whereas disease severity of Septoria tritici blotch might decrease in France end of this century. Thus, wheat disease problems caused by a changing climate will probably not consistently worsen, as climatic changes may also improve the crop health situation in wheat depending on the location. The results of long-term simulations of future disease risk must be taken with caution, because different climate models and downscaling methods are used to make the projections and this can create considerable uncertainty. Being aware of this short-coming, plant pathologists recently started to assess the sources of uncertainty related to their long-term disease simulations. However, in spite of this progress there is still a significant lack of simulation studies related to different wheat diseases in various locations that could help to estimate future wheat grain losses due to climatic changes. Many more of these studies are certainly needed. Otherwise, the focus in the climate change debate will remain on the yield loss/gain potential due to changes in the environmental conditions only, which would neglect the important impact of altered biotic constraints such as diseases which are among the key factors in the estimation of future global wheat productivity.
112 citations
Cites background from "Integrating pests and pathogens int..."
...However, yield limiting biotic factors such as diseases have been neglected in most recently reported studies (Gregory et al. 2009; White et al. 2011)....
[...]
...…inoculum pressure risk that future wheat grain yield potential might be over- or underestimated if the significant modulating effects from biotic constraints such as diseases are ignored (Gregory et al. 2009), particularly, when considering the extremely high climate sensitivity of pathogens....
[...]
...Disease simulation/forecast...
[...]
...…Unchanged in four out of six sites Volk et al. 2010 United Kingdom Speculation Presumably 2050 Little change West et al. 2012a Pyrenophora tritici-repentis (tan spot) Germany Speculation Presumably 2030 Increase von Tiedemann 1996 Canada (Ontario) Speculation Presumably 2100 Decrease Boland et…...
[...]
TL;DR: In this paper, the authors use 17 Global Circulation Model (GCM) outputs to quantify how Colombian agricultural production may be affected by climate change, and show the expected changes to years 2040-2069 (2050) under the A2 scenario of the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (SRES-A2) and the overall trends in both precipitation and temperature to 2100.
Abstract: Policy measures regarding adaptation to climate change include efforts to adjust socio-economic and ecologic systems. Colombia has undertaken various measures in terms of climate change mitigation and adaptation since becoming a party of the Kyoto protocol in 2001 and a party of the United Nations Framework Convention on Climate Change (UNFCCC) in 1995. The first national communication to the UNFCCC stated how Colombian agriculture will be severely impacted under different emission scenarios and time frames. The analyses in this document further support that climate change will severely threaten the socioeconomics of Colombian agriculture. We first query national data sources to characterize the agricultural sector. We then use 17 Global Circulation Model (GCM) outputs to quantify how Colombian agricultural production may be affected by climate change, and show the expected changes to years 2040–2069 (“2050”) under the A2 scenario of the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (SRES-A2) and the overall trends in both precipitation and temperature to 2100. We then evaluate expected changes within different regions and measure the proportion of area affected within each crop’s distributional range. By 2050, climatic change in Colombia will likely impact 3.5 million people, 14 % of national GDP corresponding to agriculture, employment of 21 % of the population, agro-industries, supply chains, and food and nutritional security. If no adaptation measures are taken, 80 % of crops would be impacted in more than 60 % of their current areas of cultivation, with particularly severe impacts in high value perennial and exportable crops. Impacts also include soil degradation and organic matter losses in the Andes hillsides; likely flooding in the Caribbean and Pacific coasts; niche losses for coffee, fruit, cocoa, and bananas; changes in prevalence of pests and diseases; and increases in the vulnerabilities of non-technically developed smallholders. There is, however, still time to change the current levels of vulnerability if a multidisciplinary focus (i.e., agronomic, economic, and social) in vulnerable sectors is undertaken. Each sub-sector and the Government need to invest in: (1) data collection, (2) detailed, regionally-based impact assessments, (3) research and development, and (4) extension and technology transfer. Support to vulnerable smallholders should be given by the state in the form of agricultural insurance systems contextualized under the phenomenon of climate change. A national coordination scheme led by (but not restricted to) the Ministry of Agriculture and Rural Development (MADR) with the contributions of national and international institutions is needed to address agricultural adaptation.
111 citations
Cites background from "Integrating pests and pathogens int..."
...Further, climate change is expected to cause shifts in the geographic distribution and incidence of pests and diseases (Gregory et al. 2009; Hijmans et al. 2000; Ramirez-Villegas et al. 2011b) and extreme weather events (IPCC 2007; Timmermann et al. 1999), which in turn are determinants of crop…...
[...]
...Pests and diseases, another important issue in the context of climate change (Garrett et al. 2009; Gregory et al. 2009), constitute a major portion of the production costs for some crops (e.g. maize, Musa, potatoes, among others)....
[...]
References
More filters
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