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: It is argued that nascent fungal infections will cause increasing attrition of biodiversity, with wider implications for human and ecosystem health, unless steps are taken to tighten biosecurity worldwide.
Abstract: The past two decades have seen an increasing number of virulent infectious diseases in natural populations and managed landscapes. In both animals and plants, an unprecedented number of fungal and fungal-like diseases have recently caused some of the most severe die-offs and extinctions ever witnessed in wild species, and are jeopardizing food security. Human activity is intensifying fungal disease dispersal by modifying natural environments and thus creating new opportunities for evolution. We argue that nascent fungal infections will cause increasing attrition of biodiversity, with wider implications for human and ecosystem health, unless steps are taken to tighten biosecurity worldwide.
2,408 citations
TL;DR: In this paper, a comprehensive summary of studies that simulate climate change impacts on agriculture are reported in a meta-analysis, which suggests that aggregate yield losses should be expected for wheat, rice and maize in temperate and tropical growing regions even under relatively moderate levels of local warming.
Abstract: A comprehensive summary of studies that simulate climate change impacts on agriculture are now reported in a meta-analysis. Findings suggest that, without measures to adapt to changing conditions, aggregate yield losses should be expected for wheat, rice and maize in temperate and tropical growing regions even under relatively moderate levels of local warming.
1,458 citations
TL;DR: This work proposes a framework based on ideas from global-change biology, community ecology, and invasion biology that uses community modules to assess how species interactions shape responses to climate change.
Abstract: Predicting the impacts of climate change on species is one of the biggest challenges that ecologists face Predictions routinely focus on the direct effects of climate change on individual species, yet interactions between species can strongly influence how climate change affects organisms at every scale by altering their individual fitness, geographic ranges and the structure and dynamics of their community Failure to incorporate these interactions limits the ability to predict responses of species to climate change We propose a framework based on ideas from global-change biology, community ecology, and invasion biology that uses community modules to assess how species interactions shape responses to climate change
1,169 citations
01 Jan 2014
TL;DR: The questions for this chapter are how far climate and its change affect current food production systems and food security and the extent to which they will do so in the future.
Abstract: Many definitions of food security exist, and these have been the subject of much debate. As early as 1992, Maxwell and Smith (1992) reviewed more than 180 items discussing concepts and definitions, and more definitions have been formulated since (DEFRA, 2006). Whereas many earlier definitions centered on food production, more recent definitions highlight access to food, in keeping with the 1996 World Food Summit definition (FAO, 1996) that food security is met when “all people, at all times, have physical and economic access to sufficient, safe, and nutritious food to meet their dietary needs and food preferences for an active and healthy life.” Worldwide attention on food access was given impetus by the food “price spike” in 2007–2008, triggered by a complex set of long- and short-term factors (FAO, 2009b; von Braun and Torero, 2009). FAO concluded, “provisional estimates show that, in 2007, 75 million more people were added to the total number of undernourished relative to 2003–05” (FAO, 2008); this is arguably a low-end estimate (Headey and Fan, 2010). More than enough food is currently produced per capita to feed the global population, yet about 870 million people remained hungry in the period from 2010 to 2012 (FAO et al., 2012). The questions for this chapter are how far climate and its change affect current food production systems and food security and the extent to which they will do so in the future (Figure 7-1).
960 citations
Cites background from "Integrating pests and pathogens int..."
...The potential influence of pests and diseases is commonly beyond the scope of such studies (Gregory et al., 2009)....
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TL;DR: This paper reviews recent literature concerning a wide range of processes through which climate change could potentially impact global-scale agricultural productivity, and presents projections of changes in relevant meteorological, hydrological and plant physiological quantities from a climate model ensemble to illustrate key areas of uncertainty.
Abstract: This paper reviews recent literature concerning a wide range of processes through which climate change could potentially impact global-scale agricultural productivity, and presents projections of changes in relevant meteorological, hydrological and plant physiological quantities from a climate model ensemble to illustrate key areas of uncertainty. Few global-scale assessments have been carried out, and these are limited in their ability to capture the uncertainty in climate projections, and omit potentially important aspects such as extreme events and changes in pests and diseases. There is a lack of clarity on how climate change impacts on drought are best quantified from an agricultural perspective, with different metrics giving very different impressions of future risk. The dependence of some regional agriculture on remote rainfall, snowmelt and glaciers adds to the complexity. Indirect impacts via sea-level rise, storms and diseases have not been quantified. Perhaps most seriously, there is high uncertainty in the extent to which the direct effects of CO2 rise on plant physiology will interact with climate change in affecting productivity. At present, the aggregate impacts of climate change on global-scale agricultural productivity cannot be reliably quantified.
828 citations
Cites background from "Integrating pests and pathogens int..."
...This may be through impacts of warming or drought on the resistance of crops to specific diseases and through the increased pathogenicity of organisms by mutation induced by environmental stress (Gregory et al. 2009)....
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References
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TL;DR: This article quantified changes in the growth and alkaloid content of wild poppy (Papaver setigerum) as a function of recent and projected changes in global atmospheric carbon dioxide concentration, [CO2].
Abstract: In the current study, we quantified changes in the growth and alkaloid content of wild poppy, (Papaver setigerum) as a function of recent and projected changes in global atmospheric carbon dioxide concentration, [CO2]. The experimental [CO2] values (300, 400, 500 and 600μmol mol−1) correspond roughly to the concentrations that existed during the middle of the twentieth century, the current concentration, and near and long-term projections for the current century (2050 and 2090), respectively. Additional carbon dioxide resulted in significant increases in leaf area and above ground biomass for P. setigerum at all [CO2] relative to the 300μmol mol−1 baseline. Reproductively, increasing [CO2] from 300 to 600μmol mol−1 increased the number of capsules, capsule weight and latex production by 3.6, 3.0 and 3.7×, respectively, on a per plant basis. Quantification of secondary compounds (i.e. those not involved in primary metabolism) included the alkaloids morphine, codeine, papaverine and noscapine. The amount of all alkaloids increased significantly on a per plant basis, with the greatest relative increase occurring with recent increases in atmospheric carbon dioxide (e.g. from 300 to 400μmol mol−1). Overall, these data suggest that as atmospheric [CO2] continues to increase, significant effects on the production of secondary plant compounds of pharmacological interest (i.e. opiates) could be expected.
33 citations
"Integrating pests and pathogens int..." refers background in this paper
...For example, Ziska et al. (2008a) found that elevated CO2 increased concentrations of nicotine in tobacco and scopolamine in jimson weed (Datura stramonium L.), but had no effect on atropine concentration in tobacco....
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...Likewise elevated CO2 increased production per plant of morphine, codeine, papaverine, and noscapine in wild poppy (Papaver setigerum; Ziska et al., 2008b)....
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...For example, elevated CO2 altered the production of volatile defence compounds in white cabbage (Brassica oleracea) responsible for recruiting natural enemies (Cotesia plutellae) of the diamond back moth (Plutella xylostella), resulting in lower searching efficacy of C. plutellae (Vuorinen et al.,…...
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TL;DR: Studies of oat lines carrying single or several resistance genes indicate that thermal sensitivity of the reactions conditioned by the genes conferring labile resistance is not affected by the presence of genes confering stable resistance or by the rest of the host plant genotype.
Abstract: Six of the identified genes for stem rust (Puccinia graminis Pers. f. sp. avenae Erikss. and Henn.) resistance in oats (Avena sativa L.) are divided into three categories of thermal sensitivity: re...
31 citations
"Integrating pests and pathogens int..." refers background in this paper
..., 1984), and to Puccinia tritici in oats (Martens et al., 1967)....
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...Similar temperature sensitivities have been reported previously to the same rust (Dyck and Johnson, 1983), to Puccinia striiformis (Gerechter-Amitai et al., 1984), and to Puccinia tritici in oats (Martens et al., 1967)....
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TL;DR: Drought stress alters plant metabolism, causing changes in growth, hormone levels, photosynthesis, and nutrient uptake, in resistant alfalfa clones infected with V. albo-atrum.
Abstract: Drought stress alters plant metabolism, causing changes in growth, hormone levels, photosynthesis, and nutrient uptake. Verticillium alboatrum reduces growth and stomatal conductance in resistant alfalfa clones in the absence of abiotic stress. The additional effect of drought stress on the growth of resistant alfalfa infected with V. albo-atrum is unknown; consequently, experiments were conducted to assess the stability of resistance to V. albo-atrum in alfalfa grown under the stress of drought. Two resistant alfalfa clones were grown in the greenhouse in 0.03-m 3 cylinders that allowed the development of a gradually increasing drought stress (...)
31 citations
"Integrating pests and pathogens int..." refers background in this paper
...Under drought stress, pathogens can have reduced impact or symptoms (Huber and Gillespie, 1992; Pennypacker et al., 1991), but resistance expression can also be reduced (Christiansen and Lewis, 1982)....
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Journal Article•
TL;DR: The data suggest that pathogen resistance increased in the plants that were acclimated to the enhanced ozone level, and recovery of this parameter was faster in seedlings ozonated at 180 ppb.
Abstract: In the study the effect of elevated ozone concentrations on plant metabolic efficiency and plant resistance to necrotrophic fungi was estimated, Seedlings of spring barley, meadow fescue and winter rape were fumigated for 12 days with 130 and 180 ppb of ozone. Measurements of heat emission and respiration intensity after 6, 9 and 12 days since the start of fumigation were performed. At the same time, plants were artificially inoculated - barley and fescue with conidia and mycelium of Bipolaris sorokiniana, rape with mycelium of Phoma lingam. The experiment showed a positive effect of the fumigation with the higher dose of ozone on resistance of all studied plant species to fungal infection. Ozone fumigation induced a decrease in metabolic efficiency (heat rate per O 2 consumption) of plants. Recovery of this parameter was faster in seedlings ozonated at 180 ppb. The data suggest that pathogen resistance increased in the plants that were acclimated to the enhanced ozone level.
31 citations
"Integrating pests and pathogens int..." refers background in this paper
...Elevated levels of both ozone and CO2 can also affect expression of resistance more directly (Plazek et al., 2001; Plessl et al., 2005)....
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TL;DR: The E. coli strain IC3821 could be useful for the detection of SOS-dependent mutagenesis induced by chemical oxidants and revertants were induced by t-butyl hydroperoxide with higher efficiency than in oxyR+.
26 citations
"Integrating pests and pathogens int..." refers background in this paper
...Enhanced mutation rate is specifically related to an increased background of reactive oxygen species characteristically produced in stress responses (Blanco et al., 1995)....
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