Historical dynamics in ecosystem service bundles Renard, Delphine; Rhemtulla, Jeanine M.; Bennett, Elena M.
Proceedings of the National Academy of Sciences - PNAS,
10/2015, Letnik:
112, Številka:
43
Journal Article
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Managing multiple ecosystem services (ES), including addressing trade-offs between services and preventing ecological surprises, is among the most pressing areas for sustainability research. These ...challenges require ES research to go beyond the currently common approach of snapshot studies limited to one or two services at a single point in time. We used a spatiotemporal approach to examine changes in nine ES and their relationships from 1971 to 2006 across 131 municipalities in a mixed-use landscape in Quebec, Canada. We show how an approach that incorporates time and space can improve our understanding of ES dynamics. We found an increase in the provision of most services through time; however, provision of ES was not uniformly enhanced at all locations. Instead, each municipality specialized in providing a bundle (set of positively correlated ES) dominated by just a few services. The trajectory of bundle formation was related to changes in agricultural policy and global trends; local biophysical and socioeconomic characteristics explained the bundles’ increasing spatial clustering. Relationships between services varied through time, with some provisioning and cultural services shifting from a trade-off or no relationship in 1971 to an apparent synergistic relationship by 2006. By implementing a spatiotemporal perspective on multiple services, we provide clear evidence of the dynamic nature of ES interactions and contribute to identifying processes and drivers behind these changing relationships. Our study raises questions about using snapshots of ES provision at a single point in time to build our understanding of ES relationships in complex and dynamic social-ecological systems.
Ensuring the temporal stability of national food production is crucial for avoiding sharp drops in domestic food availability. The average stability of individual crop yields and asynchrony among ...crop yield fluctuations are two candidate mechanisms to stabilize national food production. However, the quantification of their respective influence on the stability of national food production is lacking, as is the identification of the factors regulating both mechanisms. Using yield data for 138 crops and 115 countries over a 50-year period, we first show that the stability of total national yield mostly relies on the fluctuations of the yield of crops covering the largest share of cropland. The average yield stability of these crops exert a stabilizing effect on national food production that is twice as important as the one of the asynchronous yield fluctuations among them. Climate variability reduces the stability of national food production by synchronizing yield fluctuations among crops and destabilizing the yield of individual crops. However, our results suggest that increasing crop diversity can counteract the synchronizing effects of climate variability by enhancing asynchronous dynamics among crops. Irrigation can promote the average stability of individual crop yields but cannot compensate for the destabilizing effect of climate variability. Considering both the response of each crop to climatic variations and the dynamics emerging from crop baskets will help agricultural policies to ensure stable food supply at the national level.
Abstract
Weather extremes like droughts and heat waves are becoming increasingly frequent worldwide, with severe consequences for agricultural production and food security. Although the effects of ...such events on the production of major crops is well-documented, the response of a larger pool of crops is unknown and the potential of crop diversity to buffer agricultural outputs against weather extremes remains untested. Here, we evaluate whether increasing the diversity of crop portfolios at the country level confers greater resistance to a country’s overall yield and revenues against losses to droughts and high temperatures. To do this, we use 58 years of annual data on weather, crop yields and agricultural revenues for 109 crops in 127 countries. We use the spatial distribution of each crop and their cropping cycle to determine their exposure to weather events. We find that growing greater crop diversity within countries reduces the negative impacts of droughts and high temperatures on agricultural outputs. For drought, our results suggest that the effect is explained not only by crop diversity itself, but also by the sensitivity of the most abundant crops (in terms of harvested areas) to this extreme. Countries dedicating more land to minor, drought-tolerant crops reduce the average sensitivity of country-scale crop portfolios and show greater resistance of yield and revenues to drought. Our study highlights the unexploited potential for putting crop biodiversity to work for greater resilience to weather, specifically in poorer developing countries that are likely to suffer disproportionately from climate change impacts.
Increasing global food demand, low grain reserves and climate change threaten the stability of food systems on national to global scales
. Policies to increase yields, irrigation and tolerance of ...crops to drought have been proposed as stability-enhancing solutions
. Here we evaluate a complementary possibility-that greater diversity of crops at the national level may increase the year-to-year stability of the total national harvest of all crops combined. We test this crop diversity-stability hypothesis using 5 decades of data on annual yields of 176 crop species in 91 nations. We find that greater effective diversity of crops at the national level is associated with increased temporal stability of total national harvest. Crop diversity has stabilizing effects that are similar in magnitude to the observed destabilizing effects of variability in precipitation. This greater stability reflects markedly lower frequencies of years with sharp harvest losses. Diversity effects remained robust after statistically controlling for irrigation, fertilization, precipitation, temperature and other variables, and are consistent with the variance-scaling characteristics of individual crops required by theory
for diversity to lead to stability. Ensuring stable food supplies is a challenge that will probably require multiple solutions. Our results suggest that increasing national effective crop diversity may be an additional way to address this challenge.
1. Agriculture's influence on humanity is a dichotomy of promise and peril. Research on the food-environment dilemma has highlighted the environmental consequences of food production, yet the ...identification of management solutions is an ongoing challenge. 2. We suggest "bright spots" as a promising tool to identify levers of change by finding areas that exceed expectations for goals, such as agricultural landscape multifunctionality and biodiversity. 3. We identified bright, dark and average spots within a complex agricultural landscape and explored the associated socioeconomic patterns. We found that areas exceeding expectations for biodiversity and landscape multifunctionality were neither spatially congruent nor in conflict. It was more common for areas to underperform (dark spots) for both biodiversity and multifunctionality than over perform for both (bright spots). 4. While dark spots for multifunctionality were alike in their ecosystem service composition, bright spots were bright in multiple, diverse ways. The socioeconomic attributes that characterize bright and darks spots included both farm characteristics as well as farming practices, suggesting that both have potential to be levers of change. 5. Synthesis and applications. Our results suggest that while biodiversity and landscape multifunctionality show similar spatial patterns due to underlying biophysical drivers, managing for biodiversity or landscape multifunctionality alone will not implicitly achieve the other in this system. Bright spots (areas exceeding expectations) in multifunctionality were associated with many different combinations of ecosystem services, but dark spots were uniquely agricultural intensive areas devoted to maximizing crop production at the expense of all other services. From a management perspective, specific farm characteristics and farming practices may impact the potential for multifunctionality: increased mechanization, increased agricultural inputs and larger farm size and capital were associated with dark spots, while smaller farms with potentially greater space for innovation were associated with bright spots.
Determinants of farmer well-being can be derived from objective and subjective measures of social components, environmental sustainability indicators, and quality of life indices, as well as the ...multiple scales that farms and farmers operate. Yet, despite multiple frameworks on farmer well-being, the extent to which farmer-expressed values are used in the development of farmer well-being indicators is unclear. Challenges can arise from extracting indicators that are insufficiently grounded in place, or that inadequately incorporate context and biocultural relations and practices. Here in this scoping review, we synthesize the methodologies in the literature on assessing farmer well-being and identify the extent to which farmer well-being domains are derived from values expressed directly by farmers. We consolidated and coded 92 papers to respond to the following questions: (1) What are the most frequent farmer well-being domains in published studies? (2) What methods are used to elicit multidimensional farmer well-being domains? (3) Do well-being domains used in the literature adequately reflect a biocultural context, including place-based influences on well-being? Our results show that economics and social relationships are frequent domains of how farmer well-being is identified and assessed. These domains tend to be measured simultaneously, while less common domains, such as governance and place, are rather isolated. A suite of methods was used to assess well-being domains, ranging from basic surveys to in-depth participant observation. Yet, we identify gaps in the methods for deriving farmer well-being indicators. Specifically, methods that refer to farmer-expressed values were rare and domains identified through a place-based approach were often not recorded, but, arguably, critical in developing multidimensionality of farmer well-being. We show that while the translocal approach is well represented in established well-being frameworks, farmer expression is not foundational in well-being assessments but is needed in order to center farmer values when generating indicators of well-being.
A confluence of discoveries in ecology and agriculture suggests that biodiversity can help address the sustainability problems facing modern intensive agriculture. Here we explore several questions ...related to this possibility. Can increases in national crop diversity help increase the stability and security of national food systems? Can practices based on greater crop biodiversity produce yields that compete with those obtained through the long-standing, high-input monoculture model? What are the appropriate levels and combinations of crops to be used? We highlight recent research that suggests it is time to begin unlocking the agricultural potential of biodiversity — from the level of crop genetic diversity to species diversity — and to do so on spatial scales from individual fields to nations. Recent research suggests that the biodiversification of agriculture may lead to greater and more stable yields, decrease land clearing, and lower the use of harmful agrochemicals.
Just four plant species — wheat, rice, maize and soybeans — provide more than 60% of the calories we consume. In this Essay, Delphine Renard and David Tilman discuss the risks of monoculture and how the biodiversification of agriculture may lead to greater and more stable yields, minimize land clearing, and reduce the use of harmful agrochemicals.
Abstract
Much evidence supports the ecological and agronomic benefits of diversity, of both crops and environments, for building resilience and sustainability in agroecosystems. Farmers' knowledge ...about crop diversity is well‐documented, but aside from studies on how farmers exchange seeds and knowledge through networks, the interactions of social factors and the diversity of crops and cultivated environments have been mainly overlooked. One factor receiving attention is farmers' access to land, but in only one of its dimensions, the security of access. Here we address the different strategies by which farmers gain access to land. How does the plurality of modes of access to land influence crop choices, and thereby crop diversity? How does this plurality influence the range of environments available to individual farmers for cultivating crop diversity?
Analysing data from 51 interviews with farmers and 312 plots in agrosilvopastoral systems in northwestern Morocco, we described eight different modes of access. Each mode offers different opportunities and constraints concerning the kind of crops that can be grown on the plot. We found that an increase in the number of modes of access to land increases the crop diversity of farmers' holdings, regardless of the total area each farmer cultivates. Accessing additional plots contributed to both environmental heterogeneity and to crop diversity of farms.
In striving to gain access to land and to grow diverse crops, farmers are motivated by their notion of what it means to be a ‘real farmer’, that is, the relation to their identity. Farmers mobilize not only their economic power but also their social relationships to gain access to plots of land. Their choices are also based on their relationships to tree crops such as olive, which are economic and cultural keystone species, as well as markers of land ownership and control.
Multiple modes of access to land characterize many smallholder farming systems, which support a large fraction of the world's population. Recognizing diverse social practices of access to land that allow farmers to continue to mobilize multiple modes of access can increase resilience against unpredictable events and help maintain sustainable agroecosystems.
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Plain Language Summary
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Résumé
Résumé
De nombreuses études mettent en évidence les rôles écologiques et agronomiques de la diversité, tant des cultures que des environnements, dans la résilience et la durabilité des agroécosystèmes. Les savoirs des agriculteurs et agricultrices liés à la diversité des plantes cultivées sont bien documentés, mais en dehors des études sur les réseaux d'échanges de semences ou de connaissances, les facteurs sociaux ont été largement négligés pour comprendre la diversité des plantes et des environnements cultivés. Un de ces facteurs est l'accès des agriculteurs à la terre, mais il a été uniquement étudié sous l'angle de la sécurité de l'accès. Nous abordons ici les différentes stratégies par lesquelles les agriculteurs accèdent à la terre. Comment la pluralité des modes d'accès à la terre influence‐t‐elle les choix des cultures, et par conséquent la diversité des plantes cultivées? Comment cette pluralité influence‐t‐elle la gamme d'environnements disponibles pour chaque agriculteur afin de cultiver une diversité de plantes?
En analysant les données de 51 entretiens avec des agriculteurs et de 312 parcelles dans des systèmes agrosylvopastoraux dans le nord‐ouest du Maroc, nous avons décrit huit modes d'accès à la terre différents. Chaque mode offre différentes opportunités et contraintes concernant le type de cultures qui peuvent être cultivées sur la parcelle. Nous avons mis en évidence une relation positive entre la diversité des modes d'accès à la terre et la diversité des plantes cultivées, relation indépendamment de la superficie totale cultivée par chaque agriculteur. L'accès à des parcelles supplémentaires contribue à la fois à l'hétérogénéité environnementale et à la diversité des plantes cultivées dans les fermes.
Les efforts pour accéder à la terre et cultiver diverses plantes met en jeu ce qu'être un ‘vrai agriculteur’ signifie. Les agriculteurs mobilisent non seulement leur capital économique, mais aussi leurs relations sociales pour accéder à de nouvelles parcelles tout au long de l'année. Les cultures arboricoles telles que l'olivier, qui sont des espèces clés sur le plan économique et culturel, sont par ailleurs des indicateurs de propriété et des moyens de contrôle fonciers.
La multiplicité des modes d'accès à la terre caractérise de nombreux systèmes de petite agriculture, qui concernent une grande partie de la population mondiale. Reconnaître les diverses pratiques sociales qui permettent aux agriculteurs de continuer à mobiliser plusieurs modes d'accès à la terre peut accroître la résilience face à des événements imprévisibles et contribuer au maintien d'agroécosystèmes durables.
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In the current setting, marked by the major challenges of growing food demand and climate change impacts, the ability of sub-Saharan agriculture to meet population needs depends on the resilience and ...adaptation capacity of this system. Using agrobiodiversity to promote agricultural sustainability is a strategy that has garnered much attention lately. Research suggests that mixing species or varieties within crop fields could increase the yield and/or stability. This mixing is also geared towards the conservation of crop diversity while ensuring that the various associated products and services will be available at the farm level.
Few recent research studies have highlighted the benefits of varietal mixtures for Africa. This lack of research is a concern, given that this continent is considered to be highly vulnerable to climate change. This study was carried out to test whether plots with varietal mixtures would outperform monovarietal plots in terms of yield and pathogen regulation under smallholder farming conditions in Senegal. Together with farmers, we conducted 30 experiments in which mixtures of early- and late-flowering pearl millet landraces were grown in these farmers’ fields, while monitoring their low input management. We noted a significant positive effect of varietal mixtures on grain yield (mean gain of 63 ± 31.5 kg ha−1 for mixture plots, p = 0.046) with a relative yield total (RYT) averaging 1.87 ± 0.94. Both early- and late-flowering landraces benefited from mixtures, with a greater impact on late-flowering landraces. Higher fertility in terms of the seed number, percentage of fertile tillers and number of panicles per tiller, was documented in mixture plots. We did not find a significant effect of mixture on fodder, striga or weed infestation.
In water and nutrient resource limiting conditions, such as in Sahelian agroecosystems, growing mixtures of early- and late-flowering landraces appeared to be an efficient way to increase productivity while ensuring agrobiodiversity conservation. Perhaps even more importantly, mixtures allowed farmers to harvest multiple products with different uses in an agrosocioecosystem context with constantly increasing land pressure.
Decades of theory and scholarship on the concept of human well‐being have informed a proliferation of approaches to assess well‐being and support public policy aimed at sustainability and improving ...quality of life.
Human well‐being is multidimensional, and well‐being emerges when the dimensions and interrelationships interact as a system. In this paper, we illuminate two crucial components of well‐being that are often excluded from policy because of their relative difficulty to measure and manage: equity and interrelationships between humans and the environment.
We use a mixed‐methods approach to review and summarize progress to date in developing well‐being constructs (including frameworks and methods) that address these two components.
Well‐being frameworks that do not consider the environment, or interrelationships between people and their environment, are not truly measuring well‐being in all its dimensions.
Use of equity lenses to assess well‐being frameworks aligns with increasing efforts to more holistically characterize well‐being and to guide sustainability management in ethical and equitable ways.
Based on the findings of our review, we identify several pathways forward for the development and implementation of well‐being frameworks that can inform efforts to leverage well‐being for public policy.
Résumé
Des décennies de théorie et de recherche sur le concept de bien‐être humain ont généré une prolifération d'approches pour évaluer le bien‐être et encourager les décideurs à intégrer la durabilité et l'amélioration de la qualité de vie dans leurs politiques publiques.
Le bien‐être humain est multidimensionnel; il est favorisé par l’interaction entre ses multiples dimensions qui constituent un système. Dans cet article, nous soulignons deux composantes cruciales du bien‐être qui sont souvent exclues des politiques publiques en raison de leur relative difficulté à mesurer et à gérer: l'équité et les relations entre les humains et l’environnement.
Nous utilisons des méthodes mixtes pour inventorier et résumer les progrès réalisés à ce jour dans le développement et l’application des cadres conceptuels du bien‐être (y compris des cadres d’analyse et des méthodes) qui traitent de ces deux composantes.
Les cadres d’analyse sur le bien‐être qui ne tiennent pas compte de l'environnement ou des relations entre les humains et l’environnement, ne mesurent pas le bien‐être dans toutes ses dimensions.
L’adoption de l’équité dans les méthodes d’évaluation du bien‐être, permet de caractériser plus holistiquement la notion de bien‐être et ainsi de développer une approche de la durabilité plus éthique et équitable.
Sur la base des résultats de notre recherche bibliographique, nous identifions plusieurs voies pour développer et opérationnaliser des cadres de travail favorisant l’intégration du bien‐être dans les politiques publiques.
Resumen
Décadas de teoría y estudios sobre el concepto de bienestar humano han informado una proliferación de enfoques para evaluar el bienestar y apoyar la política pública orientada a la sustentabilidad y mejora de la calidad de vida.
El bienestar humano es multidimensional y el bienestar surge cuando las dimensiones e interrelaciones interactúan como un sistema. En este trabajo, iluminamos dos componentes fundamentales del bienestar que frecuentemente son excluidos de políticas debido a su relativa dificultad para medir y gestionar: la equidad y las interrelaciones entre las personas y el medio ambiente.
Usamos métodos mixtos para revisar y resumir el progreso hasta la fecha en el desarrollo de construcciones de bienestar (incluyendo marcos y métodos) que abordan estos dos componentes.
Estructuras de bienestar que no consideran el medio ambiente, o interrelaciones entre las personas y su entorno, no están midiendo el bienestar en todas sus dimensiones.
El uso de enfoques de equidad para evaluar los marcos de bienestar es consistente con el aumento en esfuerzos para caracterizar más holísticamente el bienestar y para orientar la gestión de la sustentabilidad de forma ética y equitativa.
Basándonos en los hallazgos de nuestra revisión, identificamos varias vías para el desarrollo e implementación de marcos de bienestar que pueden informar iniciativas que aprovechan el bienestar para políticas públicas.
A free Plain Language Summary can be found within the Supporting Information of this article.
A free Plain Language Summary can be found within the Supporting Information of this article.
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