Agroecology and the design of climate change-resilient farming systems

Abstract

Diverse, severe, and location-specific impacts on agricultural production are anticipated with climate change. The last IPCC report indicates that the rise of CO 2 and associated "greenhouse" gases could lead to a 1.4 to 5.8°C increase in global surface temperatures, with subsequent consequences on precipitation frequency and amounts. Temperature and water availability remain key factors in determining crop growth and productivity; predicted changes in these factors will lead to reduced crop yields. Climate-induced changes in insect pest, pathogen and weed population dynamics and invasiveness could compound such effects. Undoubtedly, climate-and weather-induced instability will affect levels of and access to food supply, altering social and economic stability and regional competiveness. Adaptation is considered a key factor that will shape the future severity of climate change impacts on food production. Changes that will not radically modify the monoculture nature of dominant agroecosystems may moderate negative impacts temporarily. The biggest and most durable benefits will likely result from more radical agroecological measures that will strengthen the resilience of farmers and rural communities, such as diversification of agroecosytems in the form of polycultures, agroforestry systems, and crop-livestock mixed systems accompanied by organic soil management, water conservation and harvesting, and general enhancement of agrobiodiversity. Traditional farming systems are repositories of a wealth of principles and measures that can help modern agricultural systems become more resilient to climatic extremes. Many of these agroecological strategies that reduce vulnerabilities to climate variability include crop diversification, maintaining local genetic diversity, animal integration, soil organic management, water conservation and harvesting, etc. Understanding the agroecological features that underlie the resilience of traditional agroecosystems is an urgent matter, as they can serve as the foundation for the design of adapted agricultural systems. Observations of agricultural performance after extreme climatic events (hurricanes and droughts) in the last two decades have revealed that resiliency to climate disasters is closely linked to farms with increased levels of biodiversity. Field surveys and results reported in the literature suggest that agroecosystems are more resilient when inserted in a complex landscape matrix, featuring adapted local germplasm deployed in diversified cropping systems managed with organic matter rich soils and water conservation-harvesting techniques. The identification of systems that have withstood climatic events recently or in the past and understanding the agroecological features of such systems that allowed them to resist and/or recover from extreme events is of increased urgency, as the derived resiliency principles and practices that underlie successful farms can be disseminated to thousands of farmers via Campesino a Campesino networks to scale up agroecological practices that...

Technological Approaches to Sustainable Agriculture at a Crossroads: An Agroecological Perspective

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Pollination services mapping and economic valuation from insect communities: a case study in the Azores (Terceira Island)

“…Among other studies, Klein et al (2007), Aizen et al (2009), ), Calderone (2012 and Giannini et al (2015) show that pollination services contribute significantly to the agricultural production and subsequently assures 75% of food production worldwide ) (as well as to other flowering plants) by ensuring plant reproduction, fruit set development and dispersion (e.g. Ollerton et al 2011;Altieri et al, 2015). Notably, the pollination of some vegetable crops (e.g.…”

Impact of Climate Change Adaptation Strategies on Winter Wheat and Cropping System Performance across Precipitation Gradients in the Inland Pacific Northwest, USA

“…Crop intensification, diversification, reduced tillage, and variable N management are among the strategies proposed to mitigate and adapt monocultures to projected climate shifts (Burney et al, 2010;Smith and Olesen, 2010;Tilman et al, 2011;Powlson et al, 2014;Ponisio et al, 2015). Diversifying crop options may increase the resiliency of agroecosystems (Lin, 2011) and stabilize cropping systems vulnerable to a changing climate (Altieri et al, 2015) through agronomic (Johnston et al, 2005;Kirkegaard et al, 2008;Hansen et al, 2012;Seymour et al, 2012;Cutforth et al, 2013;Angus et al, 2015), economic (Entz et al, 2002;Zentner et al, 2002bZentner et al, , 2004, and environmental Gan et al, 2011;Davis et al, 2012) benefits. In the summer-dominate precipitation region of the North American Great Plains, soil conservation practices have enabled crop intensification through fallow replacement (Lafond et al, 1992;Anderson et al, 2003), which has increased opportunities to diversify crops (Halvorson et al, 1999;Zentner et al, 2002b;Tanaka et al, 2005;Roberts and Johnston, 2007), enhance N and water use efficiencies (Pikul et al, 2012).…”