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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01 Jan 1985
TL;DR: The impact of open-pit lignite mining on water resources creates significant conflicts between different interest groups, such as the mining industry, water supply agencies, and agriculture in the mining region as mentioned in this paper.
Abstract: The impact of open-pit lignite mining on water resources creates significant conflicts between different interest groups, such as the mining industry, water supply agencies, and agriculture in the mining region. The activities of each of the interest groups modify the water resources system and at the same time the conditions for resources use by other groups. Consequently, there is an apparent need for the analysis of regional water policies to reconcile the conflicting interests within such socio-eeonomic environmental systems. On that, a collaborative study between the International Institute for Applied Systems Analysis and Research Institutes in the German Democratic Republic (GDR) and Poland is directed.
455 citations
TL;DR: Interactions between insect herbivores and plants grown under conditions of ambient and elevated CO 2 were investigated, finding early instar larvae are restricted more by CO 2 enhancement than late instars and changes in development times are much more pronounced in young instars.
Abstract: Interactions between insect herbivores and plants grown under conditions of ambient and elevated CO 2 were investigated by analysing data on 43 herbivores, representing 61 plant-hcrbivore interactions. Changes in herbivore performance in enhanced CO 2 environments were correlated with changes in the quality of the host plants. measured as nitrogen content. water content, carbohydrate content and secondary plant compounds. The data were analysed to determine whether CO 2 mediated effects on insect performance differed between feeding guilds (leaf-chewers. leaf miners, phloem-feeders (root and shoot), xylem-feeders, whole-cell-feeders and seed-caters) or instar stage. Host-plant quality changed in elevated CO 2 ; leaf nitrogen content decreased, on average. by 15% while carbohydrates increased by 47% and secondary plant compounds (phenolics) by 31%. Water content did not change. Of the variables measured changes in nitrogen and carbohydrate levels only were found to be correlated with changes in food consumption. No differences were found in CO 2 -mediated herbivore responses on woody plant compared with non-woody plants. Insects from different feeding guilds respond to CO 2 mediated changes in host-plant quality in various ways. Leaf-chewer generally seem able to compensate for the decreased nitrogen levels in the plant tissues by increasing their food consumption (by 30%) and with no adverse effects on pupal weights. Leaf-miners only slightly increase their food consumption. The negative effect on pupal weight suggests that their population dynamics may change over several generations. Limited data on seed-eaters suggest that enhanced CO 2 conditions have no effect on these insects. Phloem-feeders and whole-cell-feeders are the only insects to show a positive CO 2 response. Population sizes generally increased in elevated CO 2 and development time of phloem-feeders was reduced by 17%. Early instar larvae are restricted more by CO 2 enhancement than late instars. Although changes in food consumption are similar. changes in development times are much more pronounced in young instars (18% vs 6%).
452 citations
01 Jan 2007
TL;DR: In this article, the role of terrestrial ecosystems in the global carbon cycle and their response to large-scale environmental change is discussed, with a focus on the effects of urban land use change on Biogeochemical cycles.
Abstract: Global change and the Earth System.- Global Ecology, Networks, and Research Synthesis.- Carbon and Water Cycles in the 21st Century.- CO2 Fertilization: When, Where, How Much?.- Ecosystem Responses to Warming and Interacting Global Change Factors.- Insights from Stable Isotopes on the Role of Terrestrial Ecosystems in the Global Carbon Cycle.- Effects of Urban Land-Use Change on Biogeochemical Cycles.- Saturation of the Terrestrial Carbon Sink.- Changing Biodiversity and Ecosystem Functioning.- Functional Diversity - at the Crossroads between Ecosystem Functioning and Environmental Filters.- Linking Plant Invasions to Global Environmental Change.- Plant Biodiversity and Responses to Elevated Carbon Dioxide.- Predicting the Ecosystem Consequences of Biodiversity Loss: the Biomerge Framework.- Landscapes under Changing Disturbance Regimes.- Plant Species Migration as a Key Uncertainty in Predicting Future Impacts of Climate Change on Ecosystems: Progress and Challenges.- Understanding Global Fire Dynamics by Classifying and Comparing Spatial Models of Vegetation and Fire.- Plant Functional Types: Are We Getting Any Closer to the Holy Grail?.- Spatial Nonlinearities: Cascading Effects in the Earth System.- Dynamic Global Vegetation Modeling: Quantifying Terrestrial Ecosystem Responses to Large-Scale Environmental Change.- Managing Ecosystem Services.- Wheat Production Systems and Global Climate Change.- Pests Under Global Change - Meeting Your Future Landlords?.- Greenhouse Gas Mitigation Potential in Agricultural Soils.- Carbon and Water Tradeoffs in Conversions to Forests and Shrublands.- Natural and Human Dimensions of Land Degradation in Drylands: Causes and Consequences.- Regions under Stress.- Southeast Asian Fire Regimes and Land Development Policy.- Global Change Impacts on Agroecosystems of Eastern China.- Terrestrial Ecosystems in Monsoon Asia: Scaling up from Shoot Module to Watershed.- Responses of High Latitude Ecosystems to Global Change: Potential Consequences for the Climate System.- Future Directions: the Global Land Project.- The Future Research Challenge: the Global Land Project.
430 citations
TL;DR: The results of this study indicate that conclusions of CO2 elevation studies cannot be directly extrapolated to a more realistic climate change scenario and the predicted negative effects ofCO2 elevation on herbivores are likely to be mitigated by temperature increase.
Abstract: The effects of elevated carbon dioxide on plant–herbivore interactions have been summarized in a number of narrative reviews and metaanalyses, while accompanying elevation of temperature has not received sufficient attention. The goal of our study is to search, by means of metaanalysis, for a general pattern in responses of herbivores, and plant characteristics important for herbivores, to simultaneous experimental increase of carbon dioxide and temperature (ECET) in comparison with both ambient conditions and responses to elevated CO2 (EC) and temperature (ET) applied separately. Our database includes 42 papers describing studies of 31 plant species and seven herbivore species. Nitrogen concentration and C/N ratio in plants decreased under both EC and ECET treatments, whereas ET had no significant effect. Concentrations of nonstructural carbohydrates and phenolics increased in EC, decreased in ET and did not change in ECET treatments, whereas terpenes did not respond to EC but increased in both ET and ECET; leaf toughness increased in both EC and ECET. Responses of defensive secondary compounds to treatments differed between woody and green tissues as well as between gymnosperm and angiosperm plants. Insect herbivore performance was adversely affected by EC, favoured by ET, and not modified by ECET. Our analysis allowed to distinguish three types of relationships between CO2 and temperature elevation: (1) responses to EC do not depend on temperature (nitrogen, C/N, leaf toughness, phenolics in angiosperm leaves), (2) responses to EC are mitigated by ET (sugars and starch, terpenes in needles of gymnosperms, insect performance) and (3) effects emerge only under ECET (nitrogen in gymnosperms, and phenolics and terpenes in woody tissues). This result indicates that conclusions of CO2 elevation studies cannot be directly extrapolated to a more realistic climate change scenario. The predicted negative effects of CO2 elevation on herbivores are likely to be mitigated by temperature increase.
427 citations
"Integrating pests and pathogens int..." refers background in this paper
...Most studies continue to address the responses of crop pests to separate variables (usually elevated [CO2] or temperature), but some studies have illustrated the importance of combining climatic variables for more realistic climate change scenarios (Zvereva and Kozlov, 2006)....
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Book•
01 Jan 2002
TL;DR: In this article, the impact of climate change on agro-ecosystems in the context of the world food and agricultural system has been assessed using the Basic Linked System (BLS) model.
Abstract: The challenge of agriculture in the 21st century requires a systemic integration of the environmental, social and economic pillars of development to meet the needs of present generations without sacrificing the livelihoods of future generations. Over the next 50 years, the world population is projected to increase by some 3 billion, primarily in the developing countries. Yet, even today, some 800 million people go hungry daily, and more than a billion live on less than a dollar a day. This food insecurity and poverty affecting one-quarter of the world's population is a sad indictment of the failure to respond adequately in a time of unprecedented scientific progress and economic development. There is no way we can meet food security and poverty concerns without first addressing the issues of sustainable agricultural and rural development.
The methodology and results reported in this study form a first comprehensive and integrated global ecological-economic assessment of the impact of climate change on agro-ecosystems in the context of the world food and agricultural system. The Food and Agriculture Organization of the United Nations (FAO) and the International Institute for Applied Systems Analysis (IIASA) have developed a comprehensive methodology based on environmental principles, referred to as the agro-ecological zones methodology. This GIS-based framework combines crop modeling and environmental matching procedures to identify crop-specific environmental limitations under various levels of inputs and management conditions. This has facilitated comprehensive and geographically detailed assessments of climate-change impacts and agricultural vulnerability.
The sensitivity of agro-ecosystems to climate change, as determined by the FAO/IIASA Agro-ecological Zones (AEZ) model, was assessed within the socio-economic scenarios defined by the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions (SRES). For this purpose, IIASA's global linked model of the world food system was used. This modeling framework, referred to as the Basic Linked System (BLS), comprises a representation of all major economic sectors, and views national agricultural systems as embedded in national economies, which in turn interact with each other at the international level.
The BLS is a global general equilibrium model system for analyzing agricultural policies and food system prospects in an international setting. BLS views national agricultural systems as embedded in national economies, which interact with each other through financial flows and trade at the international level. The national models linked in the BLS cover about 80% of the most important attributes related to the world food system, such as population, land, agricultural production, demand, and trade. The remaining countries of the world are grouped into 14 regional models to provide closure for the world system, both geographically and economically. The national models simulate the behavior of producers, consumers, and the government. They distinguish two broad sectors: agriculture and non-agriculture. Agriculture produces nine aggregate commodities.
The combination of AEZ and BLS provides an integrated ecological-economic framework for the assessment of the impact of climate change. We consider climate scenarios based on experiments with four General Circulation Models (GCM), and we assess the four basic socioeconomic development pathways and emission scenarios as formulated by the IPCC in its Third Assessment Report.
The main results of the study include climate-change impacts on the prevalence of environmental constraints to crop agriculture; climate variability and the variability of rain-fed cereal production; changes in potential agricultural land; changes in crop production patterns; and the impact of climate change on cereal production potential. Results of the AEZ-BLS integrated ecological-economic analysis of climate change on the world food system includes quantification of scale and location of hunger, international agricultural trade, prices, production, land use, etc. The analysis assesses trends in food production, trade, and consumption, and the impact on poverty and hunger of alternative development pathways and varying levels of climate change.
The methodology and database developed in this study provides a foundation for detailed country studies, incorporating country-level information. The climate change issue is global, long term and involves complex interaction between climatic, environmental, economic, political, institutional, social and technological processes. It has significant international and intergenerational implications in the context of equity and sustainable development. Climate change will impact on social, economic and environmental systems and shape prospects for sustainable agricultural and rural development. Adaptation to climate change is essential to complement climate change mitigation, and both have to be central to an integrated strategy to reduce risks and impacts of climate change.
Most of the discussion on climate change has focused on mitigation measures, for example the Kyoto Protocol. Not much attention has been given to climate change adaptation, which will be critical for many developing countries. The developing world has not realized that this issue needs to be on the global agenda and for developed countries this is not a priority, as they have the means and resources to adapt to future climate change.
National governments and the international community must give agriculture and rural sector the highest priority in terms of resource allocation and adoption of development polices that are locally relevant and globally consistent. Only then progress can be made to eradicate hunger and poverty in the world.
420 citations
Additional excerpts
...Overall, the results of this and subsequent work demonstrated that climate change would benefit the cereal production of developed countries more than the developing countries, even if cropping practices evolved to allow more than one rainfed crop per year (Fischer et al., 2002, 2005)....
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