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The threat of global climate change has caused concern among scientists because crop production could be severely affected by changes in key climatic variables that could compromise food security both globally and locally. Although it is true that extreme climatic events can severely impact small farmers, available data is just a gross approximation at understanding the heterogeneity of small scale agriculture ignoring the myriad of strategies that thousands of traditional farmers have used and still use to deal with climatic variability. Scientists have now realized that many small farmers cope with and even prepare for climate change, minimizing crop failure through a series of agroecological practices. Observations of agricultural performance after extreme climatic events in the last two decades have revealed that resiliency to climate disasters is closely linked to the high level of on-farm biodiversity, a typical feature of traditional farming systems. Based on this evidence, various experts have suggested that rescuing traditional management systems combined with the use of agroecologically based management strategies may represent the only viable and robust path to increase the productivity, sustainability and resilience of peasant-based agricultural production under predicted climate scenarios. In this paper we explore a number of ways in which three key traditional agroecological strategies (biodiversification, soil management and water harvesting) can be implemented in the design and management of agroecosystems allowing farmers to adopt a strategy that both increases resilience and provides economic benefits, including mitigation of global warming.

Urban agriculture is considered by many scientists and policymakers as a key strategy to build climate change-resilient communities within cities by strengthening food systems, with positive food security, biodiversity, nutrition and health outcomes. The estimated potential of urban agriculture to provide between 15 and 20% of the global food supply can be enhanced by applying agroecological principles and practices that revitalize urban agriculture cropping systems, thus leading to the design of highly diversified, productive and resilient urban farms on a planet in polycrisis. Two pillars are used in agroecology: (a) restoring spatial and temporal crop combinations that deter pests by enhancing biological control with natural enemies, and (b) increasing soil organic matter through green manures, compost and other organic practices that enhance soil fertility and beneficial microorganisms. In addition to technical and environmental obstacles, there are a series of social, economic and political barriers that limit the scaling-up of urban agriculture. For this reason, it is important to launch policies that establish mechanisms for cities to provide incentives for urban agriculture, including access to land, water, seeds and technical knowledge. The creation of producer–consumer networks around markets with solidarity is critical for local equitable food provision and consumption.

For years agroecologists have warned that industrial agriculture became too narrow ecologically, highly dependent on outside inputs, and extremely vulnerable to insect pests, diseases, climate change and now as demonstrated by the COVID19 pandemic prone to a complete shut down by unforeseen crisis.Like never before, COVID19 has revealed how closely linked human, animal and ecological health are. As a powerful systemic approach, agroecology reveals that the way we practice agriculture can provide opportunities for improving environmental and human health, but if done wrongly, agriculture can cause major risks to health.

Agroecosystem function is related to the positioning of the agroecosystem and its connectivity relationship with the surrounding landscape. Herein, three methodologies are presented, which allow assessment of the links between agroecosystems and the surrounding matrix, yielding information for promoting patterns and mechanisms that foster biodiversity and the provision of multiple ecosystem services such as biological pest control, as well as energy flows and material exchanges. The three methodologies are complementary when assessing agrolandscape-level interactions in situations of regional agroecological transition. Through the use of 11 indicators, a methodology (Assessment of Beneficial Insect Habitat Suitability-ABIHS) was applied in two northern California vineyards to determine whether each agrolandscape provided suitable environmental opportunities to sponsor biological insect pest control. The Main Agroecological Structure [MAS] applied in Chilean family farms elucidates some of the relationships between farms and their biophysical environment, generating data to analyze the links between agroecosystem landscapes, management practices, and insect diversity in family farms. Social Agrarian metabolism (SAM) applied in Spanish agrolandscapes quantifies the biophysical and energy flows in agricultural systems, testing whether such flows are capable of reproducing and/or improving fund elements such as soil, biodiversity, and landscape vegetation in successive production cycles. The three methodologies provide key information for the design of sustainable agroecosystems in the context of an agroecological transition.

Given the unpredictability, increasing frequency and severity of climatic events, it is crucial to determine the adaptation limits of agroecological strategies adopted by farmers in a range of environments. In times of drought many smallholders’ farmers cope with stress using a series of crop diversification and soil management strategies. Intercropping and agroforestry systems complemented with mulching and copious organic matter applications can increase water storage, enhancing crops’ water use efficiency. Although an overwhelming number of studies demonstrate that these agroecological designs and practices are associated with greater farm-level resilience, it is important to recognize the limits of resilience. The aim of this paper is to assess the limitations of agroecological practices in enhancing the ability of agroecosystems to adapt to climate change under extended drought stress which may overwhelm crops’ adaptation response. A set of agroecological practices that can extend such limits under prolonged water stress scenarios are described. Two methodologies to assess farms’ resilience to drought provide useful tools, as they can assist farmers and researchers in identifying the practices and underlying mechanisms that reduce vulnerability and enhance response capacity allowing certain farm systems to better resist and/or recover from droughts. Clearly, reducing farmers exposure to drought requires collective actions beyond the farm scale (i.e. restoring local watersheds to optimize local hydrological cycles) aspects not explored herein. When climatic events are compounded by uncertainties imposed by external economic and political conditions, farmers’ abilities to overcome adversity may be reduced, emphasizing the importance of policy support, a dimension beyond the scope of this review.

This study evaluated how the proportional area of natural habitat surrounding a vineyard (i.e. landscape diversity) worked in conjunction with crop vigor, cultivar and rootstock selection to influence biological control of the western grape leafhopper (Erythroneura elegantula Osborn). The key natural enemies of E. elegantula are Anagrus erythroneurae S. Trjapitzin & Chiappini and A. daanei Triapitsyn, both of which are likely impacted by changes in landscape diversity due to their reliance on non-crop habitat to successfully overwinter. Additionally, E. elegantula is sensitive to changes in host plant quality which may influence densities on specific cultivars, rootstocks and/or vines with increased vigor. From 2010-2013, data were collected on natural enemy and leafhopper densities, pest parasitism rates and vine vigor from multiple vineyards that represented a continuum of landscape diversity. Early in the season, vineyards in more diverse landscapes had higher Anagrus spp. densities and lower E. elegantula densities, which led to increased parasitism of E. elegantula. Although late season densities of E. elegantula tended to be lower in vineyards with higher early season parasitism rates and lower total petiole nitrogen content, they were also affected by rootstock and cultivar. While diverse landscapes can support higher natural enemy populations, which can lead to increased biological control, leafhopper densities also appear to be mediated by cultivar, rootstock and vine vigor.

Most efforts to improve agricultural production remain focused on practices driven by an intensification agenda and not by an agroecological one. Agroecology transcends the reformist notion of organic agriculture and sustainable intensification proponents who contend that changes can be achieved within the dominant agroindustrial system with minor adjustments or “greening” of the current neoliberal agricultural model. In the technological realm, merely modifying practices to reduce input use is a step in the right direction but does not necessarily lead to the redesign of a more self sufficient and autonomous farming system. A true agroecological technological conversion calls into question monoculture and the dependency on external inputs. Traditional farming systems provide models that promote biodiversity, thrive without agrochemicals, and sustain year-round yields. Conversion of conventional agriculture also requires major social and political changes which are beyond the scope of this paper.

The erratic nature, increasing prevalence, and intensity of extreme meteorological phenomena are forcing researchers and farmers to urgently develop adaptation practices to enhance the resilience of agroecosystems to climate change. It is strategically crucial to identify farming systems that have successfully endured recent climatic disturbances and understand the agroecological attributes that enabled them to resist and/or recover from droughts and hurricanes. This paper describes a number of methodologies utilized by Latin American researchers to assess agroecosystem resilience by estimating the vulnerability and the response capacity of selected farming systems to cope with climatic threats. The methodologies utilize a set of socio-ecological indicators that can be easily evaluated in the field, allowing farmers to determine whether their farms can withstand a drought or a major storm and, based on this information, select agroecological practices able to enhance the resiliency of their farms in preparation for future events. The principles and practices of resilience identified on successful, climate-resistant farms can be shared with thousands of producers, facilitating the broader adoption and scaling up of agroecological adaptation strategies.

The influence of local and landscape habitat diversification on biological control of the Western grape leafhopper (Erythroneura elegantula Osborn) by its key parasitoids Anagrus erythroneurae S. Trjapitzin & Chiappini and Anagrus daanei Triapitsyn was studied in wine grape vineyards. At the landscape scale, Anagrus rely on alternative host species in non‐crop habitats outside of the vineyard to successfully overwinter, while at the local scale vineyard diversification can provide resources, such as shelter and floral nectar, which improve parasitoid performance. In a two‐year experiment, plots with and without flowering cover crops were compared in vineyards representing a gradient of landscape diversity. While the cover crops did attract natural enemies, their populations were unchanged in the crop canopy and there was no difference in parasitism rate, leafhopper density, crop quality, or yield. Vineyards in diverse landscapes had higher early‐season abundance of Anagrus spp., which was linked to increased parasitism and decreased late‐season populations of E. elegantula. Leafhopper densities were also positively associated with crop vigor, regardless of landscape or cover crops. Flowering cover crops did increase abundance of some natural enemy species as well as parasitism rate in vineyard landscapes with intermediate levels of diversity, indicating a local × landscape interaction, although this did not lead to reductions in E. elegantula densities. These findings indicate that, in this agroecosystem, landscape diversity mediates and in many ways outweighs the influence of local diversification and that E. elegantula densities were regulated by a combination of biological control and crop vigor.

Given environmental, economic, and social costs of unilateral chemical and biotechnological interventions to control pests, there is an urgent need to transition towards a knowledge-intensive holistic approach emphasizing agroecosystem design and management. The focus will be on what makes agroecosystems susceptible and vulnerable to insect pests, pathogens and weeds, in order to design diversified agroecosystems that prevent and suppress insect pest, pathogen and weed problems. We propose a plant health model applicable to agroecosystems that feature biodiversity enhanced designs and soils rich in organic matter and microbial life, managed with low chemical loads. In such diversified farming systems, the general protection of the plant is a consequence of mutualistic above and below ground relationships between plants, insects, and soil microbial communities. From a practical standpoint, the approach involves (a) restoring plant diversity at the landscape and field level, with spatial and temporal crop combinations that deter pests and/or enhance natural enemies and (b) increasing soil organic matter through green or animal manures, compost and other amendments, which enhance antagonists that control soilborne pathogens. Polycultures promote a complex root exudate chemistry which plays an important role in recruitment of plant-beneficial microbes, some of which enhance plants’ innate immune system. Unleashing biotic interactions between plant diversity and increased microbial ecological activity generate conditions for the establishment of a diverse and active beneficial arthropod and microbial community above and below ground, essential for pest/disease regulation.