Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
Nat Commun ; 15(1): 2963, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38580639

RESUMEN

Understanding the effectiveness of conservation interventions during times of political instability is important given how much of the world's biodiversity is concentrated in politically fragile nations. Here, we investigate the effect of a political crisis on the relative performance of community managed forests versus protected areas in terms of reducing deforestation in Madagascar, a biodiversity hotspot. We use remotely sensed data and statistical matching within an event study design to isolate the effect of the crisis and post-crisis period on performance. Annual rates of deforestation accelerated at the end of the crisis and were higher in community forests than in protected areas. After controlling for differences in location and other confounding variables, we find no difference in performance during the crisis, but community-managed forests performed worse in post-crisis years. These findings suggest that, as a political crisis subsides and deforestation pressures intensify, community-based conservation may be less resilient than state protection.


Asunto(s)
Conservación de los Recursos Naturales , Bosques , Madagascar , Biodiversidad
3.
Nature ; 619(7971): 782-787, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37438520

RESUMEN

Many communities in low- and middle-income countries globally lack sustainable, cost-effective and mutually beneficial solutions for infectious disease, food, water and poverty challenges, despite their inherent interdependence1-7. Here we provide support for the hypothesis that agricultural development and fertilizer use in West Africa increase the burden of the parasitic disease schistosomiasis by fuelling the growth of submerged aquatic vegetation that chokes out water access points and serves as habitat for freshwater snails that transmit Schistosoma parasites to more than 200 million people globally8-10. In a cluster randomized controlled trial (ClinicalTrials.gov: NCT03187366) in which we removed invasive submerged vegetation from water points at 8 of 16 villages (that is, clusters), control sites had 1.46 times higher intestinal Schistosoma infection rates in schoolchildren and lower open water access than removal sites. Vegetation removal did not have any detectable long-term adverse effects on local water quality or freshwater biodiversity. In feeding trials, the removed vegetation was as effective as traditional livestock feed but 41 to 179 times cheaper and converting the vegetation to compost provided private crop production and total (public health plus crop production benefits) benefit-to-cost ratios as high as 4.0 and 8.8, respectively. Thus, the approach yielded an economic incentive-with important public health co-benefits-to maintain cleared waterways and return nutrients captured in aquatic plants back to agriculture with promise of breaking poverty-disease traps. To facilitate targeting and scaling of the intervention, we lay the foundation for using remote sensing technology to detect snail habitats. By offering a rare, profitable, win-win approach to addressing food and water access, poverty alleviation, infectious disease control and environmental sustainability, we hope to inspire the interdisciplinary search for planetary health solutions11 to the many and formidable, co-dependent global grand challenges of the twenty-first century.


Asunto(s)
Agricultura , Ecosistema , Salud Rural , Esquistosomiasis , Caracoles , Animales , Niño , Humanos , Esquistosomiasis/epidemiología , Esquistosomiasis/prevención & control , Esquistosomiasis/transmisión , Caracoles/parasitología , África Occidental , Fertilizantes , Especies Introducidas , Intestinos/parasitología , Agua Dulce , Plantas/metabolismo , Biodiversidad , Alimentación Animal , Calidad del Agua , Producción de Cultivos/métodos , Salud Pública , Pobreza/prevención & control , Organismos Acuáticos/metabolismo , Tecnología de Sensores Remotos
4.
Glob Chang Biol ; 29(11): 2926-2952, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36799496

RESUMEN

Solar-induced chlorophyll fluorescence (SIF) is a remotely sensed optical signal emitted during the light reactions of photosynthesis. The past two decades have witnessed an explosion in availability of SIF data at increasingly higher spatial and temporal resolutions, sparking applications in diverse research sectors (e.g., ecology, agriculture, hydrology, climate, and socioeconomics). These applications must deal with complexities caused by tremendous variations in scale and the impacts of interacting and superimposing plant physiology and three-dimensional vegetation structure on the emission and scattering of SIF. At present, these complexities have not been overcome. To advance future research, the two companion reviews aim to (1) develop an analytical framework for inferring terrestrial vegetation structures and function that are tied to SIF emission, (2) synthesize progress and identify challenges in SIF research via the lens of multi-sector applications, and (3) map out actionable solutions to tackle these challenges and offer our vision for research priorities over the next 5-10 years based on the proposed analytical framework. This paper is the first of the two companion reviews, and theory oriented. It introduces a theoretically rigorous yet practically applicable analytical framework. Guided by this framework, we offer theoretical perspectives on three overarching questions: (1) The forward (mechanism) question-How are the dynamics of SIF affected by terrestrial ecosystem structure and function? (2) The inference question: What aspects of terrestrial ecosystem structure, function, and service can be reliably inferred from remotely sensed SIF and how? (3) The innovation question: What innovations are needed to realize the full potential of SIF remote sensing for real-world applications under climate change? The analytical framework elucidates that process complexity must be appreciated in inferring ecosystem structure and function from the observed SIF; this framework can serve as a diagnosis and inference tool for versatile applications across diverse spatial and temporal scales.


Asunto(s)
Clorofila , Ecosistema , Clorofila/análisis , Fluorescencia , Monitoreo del Ambiente , Estaciones del Año , Fotosíntesis/fisiología
5.
Glob Chang Biol ; 29(11): 2893-2925, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36802124

RESUMEN

Although our observing capabilities of solar-induced chlorophyll fluorescence (SIF) have been growing rapidly, the quality and consistency of SIF datasets are still in an active stage of research and development. As a result, there are considerable inconsistencies among diverse SIF datasets at all scales and the widespread applications of them have led to contradictory findings. The present review is the second of the two companion reviews, and data oriented. It aims to (1) synthesize the variety, scale, and uncertainty of existing SIF datasets, (2) synthesize the diverse applications in the sector of ecology, agriculture, hydrology, climate, and socioeconomics, and (3) clarify how such data inconsistency superimposed with the theoretical complexities laid out in (Sun et al., 2023) may impact process interpretation of various applications and contribute to inconsistent findings. We emphasize that accurate interpretation of the functional relationships between SIF and other ecological indicators is contingent upon complete understanding of SIF data quality and uncertainty. Biases and uncertainties in SIF observations can significantly confound interpretation of their relationships and how such relationships respond to environmental variations. Built upon our syntheses, we summarize existing gaps and uncertainties in current SIF observations. Further, we offer our perspectives on innovations needed to help improve informing ecosystem structure, function, and service under climate change, including enhancing in-situ SIF observing capability especially in "data desert" regions, improving cross-instrument data standardization and network coordination, and advancing applications by fully harnessing theory and data.


Asunto(s)
Ecosistema , Fotosíntesis , Clorofila , Fluorescencia , Estaciones del Año
6.
Food Policy ; 105: 102167, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34703074

RESUMEN

We use the full administrative records from four leading agricultural economics journals to study the impacts of the COVID-19 pandemic on manuscript submission, editorial desk rejection and reviewer acceptance rates, and time to editorial decision. We also test for gender differences in these impacts. Manuscript submissions increased sharply and equi-proportionately by gender. Desk rejection rates remained stable, leading to increased demand for reviews. Female reviewers became eight percentage points more likely to decline a review invitation during the early stage of the pandemic. First editorial decisions for papers sent out for peer review occurred significantly faster after pandemic lockdowns began. Overall, the initial effects of the pandemic on journal editorial tasks and review patterns appear relatively modest, despite the increased number of submissions handled by editors and reviewers. We find no evidence in agricultural economics of a generalized disruption to near-term, peer-reviewed publication.

7.
PLoS One ; 16(9): e0255519, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34495951

RESUMEN

Advances in remote sensing and machine learning enable increasingly accurate, inexpensive, and timely estimation of poverty and malnutrition indicators to guide development and humanitarian agencies' programming. However, state of the art models often rely on proprietary data and/or deep or transfer learning methods whose underlying mechanics may be challenging to interpret. We demonstrate how interpretable random forest models can produce estimates of a set of (potentially correlated) malnutrition and poverty prevalence measures using free, open access, regularly updated, georeferenced data. We demonstrate two use cases: contemporaneous prediction, which might be used for poverty mapping, geographic targeting, or monitoring and evaluation tasks, and a sequential nowcasting task that can inform early warning systems. Applied to data from 11 low and lower-middle income countries, we find predictive accuracy broadly comparable for both tasks to prior studies that use proprietary data and/or deep or transfer learning methods.


Asunto(s)
Aprendizaje Automático , Desnutrición/epidemiología , Pobreza/estadística & datos numéricos , Problemas Sociales/estadística & datos numéricos , Países en Desarrollo/economía , Países en Desarrollo/estadística & datos numéricos , Humanos , Desnutrición/economía , Análisis Multivariante , Prevalencia
8.
Proc Natl Acad Sci U S A ; 118(29)2021 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-34253609

RESUMEN

Generating credible answers to key policy questions is crucial but difficult in most coupled human and natural systems because complex feedback mechanisms can confound identification of the causal mechanisms behind observed phenomena. By using explicit research designs intended to isolate the causal effects of specific interventions on community monitoring of common property resources, and on the well-being of those resources and their human neighbors, the papers in this Special Feature offer an important advance in empirical sustainability science research. Like earlier advances in my own field of development economics, however, they suffer some avoidable interpretive and ethical errors. This essay celebrates the powerful potential of design-based sustainability science studies, much of it admirably reflected in this set of papers, while simultaneously flagging opportunities to improve future work in this tradition.


Asunto(s)
Conservación de los Recursos Naturales/estadística & datos numéricos , Conservación de los Recursos Naturales/legislación & jurisprudencia , Interpretación Estadística de Datos , Investigación Empírica , Política Ambiental , Humanos , Análisis de Mediación , Ensayos Clínicos Controlados Aleatorios como Asunto/ética , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Proyectos de Investigación/normas
9.
Sci Adv ; 7(18)2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33931440

RESUMEN

Climate change will reshape ecological dynamics. Yet, how temperature increases alter the behavior and resource use of people reliant on natural resources remains underexplored. Consequent behavior shifts have the potential to mitigate or accelerate climate impacts on livelihoods and food security. Particularly within the small-scale inland fisheries that support approximately 10% of the global population, temperature changes likely affect both fish and fishers. To analyze how changing temperatures alter households' fishing behavior, we examined fishing effort and fish catch in a major inland fishery. We used longitudinal observational data from households in Cambodia, which has the highest per-capita consumption of inland fish in the world. Higher temperatures caused households to reduce their participation in fishing but had limited net effects on fish catch. Incorporating human behavioral responses to changing environmental conditions will be fundamental to determining how climate change affects rural livelihoods, food production, and food access.

10.
Nat Food ; 2(10): 758-765, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37117971

RESUMEN

Agrifood supply chains contribute to many environmental and social problems. Sustainability standards-rules that supply chain actors may follow to demonstrate their commitment to social equity and/or environmental protection-aim to mitigate such problems. We provide a narrative review of the effects of many distinct sustainability standards on different supply chain actors spanning multiple crops. Furthermore, we discuss five emerging questions-causality, exclusion, compliance and monitoring, excess supply and emerging country markets-and identify directions for future research. We find that, while sustainability standards can help improve the sustainability of production processes in certain situations, they are insufficient to ensure food system sustainability at scale, nor do they advance equity objectives in agrifood supply chains.

11.
Nat Food ; 2(6): 417-425, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37118227

RESUMEN

Progress towards many United Nations Sustainable Development Goals depends on interventions in food value chains, yet data and methods have thus far limited the production of cross-nationally comparable estimates of food value chains' magnitudes. Here we develop a standardized method and data series to estimate the distribution of consumer food expenditures between value-added activities on farms and in the post-farmgate value chain. Using data from 61 countries over 2005-2015, representing 90% of the global economy, we show that farmers receive, on average, 27% of consumer expenditure on foods consumed at home and a far lower percentage of food consumed away from home. That figure consistently falls in the 16-38% range for middle- and high-income countries and falls significantly as incomes rise. The large and growing post-farmgate food value chain merits greater attention as the world grapples with the economic, environmental and social impacts of food systems.

12.
Lancet Planet Health ; 5(1): e50-e62, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33306994

RESUMEN

Food system innovations will be instrumental to achieving multiple Sustainable Development Goals (SDGs). However, major innovation breakthroughs can trigger profound and disruptive changes, leading to simultaneous and interlinked reconfigurations of multiple parts of the global food system. The emergence of new technologies or social solutions, therefore, have very different impact profiles, with favourable consequences for some SDGs and unintended adverse side-effects for others. Stand-alone innovations seldom achieve positive outcomes over multiple sustainability dimensions. Instead, they should be embedded as part of systemic changes that facilitate the implementation of the SDGs. Emerging trade-offs need to be intentionally addressed to achieve true sustainability, particularly those involving social aspects like inequality in its many forms, social justice, and strong institutions, which remain challenging. Trade-offs with undesirable consequences are manageable through the development of well planned transition pathways, careful monitoring of key indicators, and through the implementation of transparent science targets at the local level.


Asunto(s)
Industria de Alimentos , Invenciones , Desarrollo Sostenible , Agricultura , Inteligencia Artificial , Femenino , Salud Global , Objetivos , Humanos , Masculino , Innovación Organizacional , Política Pública , Factores Socioeconómicos
13.
Food Policy ; 94: 101913, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32773920

RESUMEN

We combine nationally representative household and labor force survey data from 1992 to 2016 to provide a detailed description of rural labor market evolution and how it relates to the structural transformation of rural Vietnam, especially within the agricultural sector. Our study adds to the emerging literature on structural transformation in low-income countries using micro-level data and helps to answer several policy-related questions. We find limited employment creation potential of agriculture, especially for youth. Rural-urban real wage convergence has gone hand-in-hand with increased diversification of the rural economy into the non-farm sector nationwide and rapid advances in educational attainment in all sectors' and regions' workforce. Minimum wage laws seem to have played no significant role in increasing agricultural wages. This enhanced integration also manifests in steady attenuation of the longstanding inverse farm size-yield relationship. Farming has remained securely household-based and the family farmland distribution has remained largely unchanged. Small farm sizes have not obstructed mechanization nor the uptake of labor-saving pesticides, consistent with factor substitution induced by rising real wage rates. As rural households rely more heavily on the labor market, human capital accumulation (rather than land endowments) have become the key correlate of improvements in rural household well-being.

14.
Nat Food ; 1(6): 319-320, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37128084
15.
Front Nutr ; 6: 109, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31428615

RESUMEN

The Madagascar Health and Environmental Research-Antongil (MAHERY-Antongil) study cohort was set up in September 2015 to assess the nutritional value of seafood for the coastal Malagasy population living along Antongil Bay in northeastern Madagascar. Over 28 months of surveillance, we aimed to understand the relationships among different marine resource governance models, local people's fish catch, the consumption of seafood, and nutritional status. In the Antongil Bay, fisheries governance takes three general forms: traditional management, marine national parks, and co-management. Traditional management involves little to no involvement by the national government or non-governmental organizations, and focuses on culturally accepted Malagasy community practices. Co-management and marine national parks involve management support from either an non-govermental organization (NGO) or the national government. Five communities of varying governance strategies were enrolled into the study including 225 households and 1031 individuals whose diets, resource acquisition strategies, fisheries and agricultural practices, and other social, demographic and economic indicators were measured over the span of 3 years. Clinical visits with each individual were conducted at two points during the study to measure disease and nutritional status. By analyzing differences in fish catch arising from variation in governance (in addition to intra-annual seasonal changes and minor inter-annual changes), the project will allow us to calculate the public health value of sustainable fisheries management approaches for local populations. There is hope that coastal zones that are managed sustainably can increase the productivity of fisheries, increasing the catch of seafood products for poor, undernourished populations.

16.
Nat Sustain ; 2(6): 445-456, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-32219187

RESUMEN

Infectious diseases are emerging globally at an unprecedented rate while global food demand is projected to increase sharply by 2100. Here, we synthesize the pathways by which projected agricultural expansion and intensification will influence human infectious diseases and how human infectious diseases might likewise affect food production and distribution. Feeding 11 billion people will require substantial increases in crop and animal production that will expand agricultural use of antibiotics, water, pesticides and fertilizer, and contact rates between humans and both wild and domestic animals, all with consequences for the emergence and spread of infectious agents. Indeed, our synthesis of the literature suggests that, since 1940, agricultural drivers were associated with >25% of all - and >50% of zoonotic - infectious diseases that emerged in humans, proportions that will likely increase as agriculture expands and intensifies. We identify agricultural and disease management and policy actions, and additional research, needed to address the public health challenge posed by feeding 11 billion people.

17.
Food Policy ; 70: 1-12, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28839345

RESUMEN

The research, development practitioner, and donor community has begun to focus on food loss and waste - often referred to as post-harvest losses (PHL) - in Sub-Saharan Africa. This article reviews the current state of the literature on PHL mitigation. First, we identify explicitly the varied objectives underlying efforts to reduce PHL levels. Second, we summarize the estimated magnitudes of losses, evaluate the methodologies used to generate those estimates, and explore the dearth of thoughtful assessment around "optimal" PHL levels. Third, we synthesize and critique the impact evaluation literature around on-farm and off-farm interventions expected to deliver PHL reduction. Fourth, we suggest a suite of other approaches to advancing these same objectives, some of which may prove more cost-effective. Finally, we conclude with a summary of main points.

18.
Food Policy ; 67: 12-25, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28413243

RESUMEN

Conventional wisdom holds that Sub-Saharan African farmers use few modern inputs despite the fact that most poverty-reducing agricultural growth in the region is expected to come largely from expanded use of inputs that embody improved technologies, particularly improved seed, fertilizers and other agro-chemicals, machinery, and irrigation. Yet following several years of high food prices, concerted policy efforts to intensify fertilizer and hybrid seed use, and increased public and private investment in agriculture, how low is modern input use in Africa really? This article revisits Africa's agricultural input landscape, exploiting the unique, recently collected, nationally representative, agriculturally intensive, and cross-country comparable Living Standard Measurement Study-Integrated Surveys on Agriculture (LSMS-ISA) covering six countries in the region (Ethiopia, Malawi, Niger, Nigeria, Tanzania, and Uganda). Using data from over 22,000 households and 62,000 agricultural plots, we offer ten potentially surprising facts about modern input use in Africa today.

19.
Food Policy ; 67: 64-77, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-28413247

RESUMEN

This paper uses the recently collected Living Standard Measurement Study-Integrated Surveys on Agriculture Initiative data sets from five countries in Sub-Saharan Africa to provide a comprehensive overview of factor market participation by agrarian households and to formally test for failures in rural markets. Under complete and competitive markets, households can solve their consumption and production problems separately, so that household factor endowments do not predict input demand. This paper implements a simple, theoretically grounded test of this separation hypothesis, which can be interpreted as a reduced form test of market failure. In all five study countries, the analysis finds strong evidence of factor market failure. Moreover, those failures appear general and structural, not specific to subpopulations defined by gender, geography, human capital, or land quality. However, we show that rural markets are not generally missing in an absolute sense, suggesting that market existence is less of a problem than market function.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...