Integrating pests and pathogens into the climate change/food security debate

Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK.
Journal of Experimental Botany (Impact Factor: 5.53). 05/2009; 60(10):2827-38. DOI: 10.1093/jxb/erp080
Source: PubMed


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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    • "Integration of pests and pathogens into food security–climate change research has been advocated convincingly (Gregory et al. 2009; Newton, Johnson & Gregory 2011), but the role of ecological service providers like dung beetles has received far less attention. Our results "
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    ABSTRACT: Climate change models predict more extreme rainfall patterns, ranging from droughts to deluges, which will inevitably affect primary productivity in many terrestrial ecosystems. Insects within the ecosystem, living above- and belowground, may modify plant responses to water stress. For example, some functional groups improve soil conditions via resource provision, potentially alleviating water stress. Enhanced resource provision may, however, render plants more susceptible to herbivores and negate beneficial effects.Using a model system, we tested how plants (Brassica oleracea) responded to drought, ambient and increased precipitation scenarios when interacting with both a soil conditioning ecosystem engineer (dung beetles; Bubas bison) and an aboveground herbivore, the major crop pest Diamond back moth (Plutella xylostella).Dung beetles enhanced soil water retention by 10% and promoted growth in plants subjected to drought by 280%, relieving the impacts of water stress on plants. Under drought conditions, plants grown with dung beetles had c. 30% more leaves and were over twice as tall as those without dung beetles. Dung beetles produced a 2.7 fold increase in nitrogen content and more than a threefold increase in carbon content of the shoots, though shoot concentrations of nitrogen and carbon were unchanged. Carbon concentrations in roots, however, were increased by dung beetles under both ambient and increased precipitation regimes.Increased precipitation reduced root and shoot nitrogen concentrations by 16% and 30%, relative to plants under ambient regimes, respectively, most likely due to dilution effects of increased plant growth under increased precipitation. Soil carbon and nitrogen concentrations were largely unaffected.While dung beetles enhanced plant growth and nitrogen content in plants experiencing drought, the anticipated increase in plant suitability to herbivores did not arise, possibly because shoot nitrogen concentrations and C:N ratio were unaffected.To our knowledge, this is the first report of an insect ecosystem engineer alleviating the effects of predicted drought events on plants via physical manipulation of the soil matrix. Moreover, their effects did not change plant suitability to an aboveground herbivore, pointing to potential beneficial role for insect ecosystem engineers in climate change adaptation and crop protection.This article is protected by copyright. All rights reserved.
    Functional Ecology 10/2015; DOI:10.1111/1365-2435.12582 · 4.83 Impact Factor
    • "Most analyses tend to focus on long-term food supply issues, notably the availability of sufficient land and irrigation water to maintain circa 90% self-sufficiency in food grains and the vulnerability of food production to climate change. However, the environmental impacts also lower current food security, for example, by increasing pest attacks and reducing soil productivity (Gregory et al., 2009). Moreover, the economic impacts include lower access of the poor to food by reducing farm incomes and increasing food prices (SAIN, 2010). "
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    ABSTRACT: China’s successful achievement of food security in recent decades has resulted in serious damage to the environment upstream of the agricultural sector, on farm and downstream. The environmental costs of this damage are not only agro-ecosystem function and the long-term sustainability of food production, but also bio-physical including human health with impacts at all levels from the local to the global, and with economic loss estimates ranging from 7 to 10% of China’s agricultural gross domestic product (GDP).
    Agriculture Ecosystems & Environment 05/2015; 209. DOI:10.1016/j.agee.2015.02.014 · 3.40 Impact Factor
    • "and pest proliferation (Gregory et al., 2009). Changes in precipitation patterns increase the likelihood of short-run crop failures and long-run production declines. "
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    ABSTRACT: Purpose - The purpose of this paper is to show how climatic change in Africa is expected to lead to a higher occurrence of severe droughts in semiarid and arid ecosystems. Understanding how crop productions react to such events is, thus, crucial for addressing future challenges for food security and poverty alleviation. Design/methodology/approach - The authors explored how temperature and rainfall patterns determined maize and beans production in Hai District in Kilimanjaro Region, Tanzania. Findings - Annual food crops were particularly sensitive to the drought and maize and beans yields were lower than perennial crops during the years of drought. The authors also report strong and significant association between maize and beans production with temperature and rainfall patterns. Practical implications - This study highlights how severe droughts can dramatically affect yields of annual crops and suggests that extreme climatic events might act as a major factor affecting agriculture production and food security, delaying or preventing the realization of the Millennium Development Goals. Originality/value - This is the first study that highlights how severe droughts can dramatically affect yields of annual crops in Hai District contributing to other climate studies done elsewhere in Tanzania and the world at large.
    International Journal of Climate Change Strategies and Management 03/2015; 7(1):17-26. DOI:10.1108/IJCCSM-07-2013-0094 · 0.43 Impact Factor
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