Pollinators support the nutrition and income of vulnerable communities | Nature

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Subjects

- Agroecology

- Developing world

- Ecological networks

- Ecosystem services

- Nutrition

Abstract

Biodiversity loss threatens human health and welfare through the degradation of ecosystem services like pollination1,2,3. However, without clear mechanistic links between ecosystems and people, these services can remain abstract and intangible. Consequently, it is challenging to predict the effects of environmental degradation on human welfare or to identify effective ecological interventions that improve human lives. Here we record individual-level diets, crop yields, farming income and crop–pollinator interactions in replicate smallholder communities in Nepal to quantify the links among insect pollinators, crop plants and nutrient intake and income of individual families. Insect pollinators were directly responsible for 44% of people’s farming income and more than 20% of their vitamin A, folate and vitamin E intake. We show how declines in local pollinator species are anticipated to exacerbate rates of poverty and micronutrient deficiency in vulnerable communities such as the ones studied here. However, our results demonstrate that management of local pollination services can improve human nutrition and household income. Indeed, abundant pollinators like native honeybees, bumblebees and hoverflies are the most important for sustaining and enhancing nutrient flows. Applied more widely, this approach of linking biodiversity to human health and livelihoods could reveal sustainable new pathways for improving the lives of millions of smallholders worldwide.

Main

Biodiversity underpins almost every aspect of human health. Clean air, fresh water, disease regulation and food production all rely on the functioning of healthy ecosystems3,4. Rapid habitat and species loss and the disruption of ecological interactions therefore jeopardize the health and wellbeing of people, particularly in low-income contexts in which rates of ill health and poverty are already high2,5,6. To address this risk, we must understand and harness the pathways that link biodiversity to human health7.

Pollination is an example of a key relationship between ecosystems and human health that is being degraded through shifting environmental and anthropogenic pressures8,9,10. Pollination supports the production of 75% of the world’s crop species, including many of the most nutritious crops that provide a large proportion of our key micronutrients, such as vitamin A, vitamin C and folate11,12. Inadequate intake of these micronutrients leads to increased mortality from infectious disease and birth defects, as well as impaired physical and cognitive development. Together, such outcomes contribute to intergenerational cycles of poverty and ill health13,14. One-quarter of the global population currently suffer from this ‘hidden hunger’15. Ongoing declines in pollinator species are anticipated to further degrade global health by reducing the yields and consumption of pollinator-dependent micronutrient-rich crops, which in turn may lead to increased rates of mortality and illness1,16,17,18. Reductions in pollination services will also result in substantial economic losses19, which are expected to further exacerbate rates of malnutrition20. These pressures will be felt most acutely by the 2 billion smallholders in low-income countries, where rates of poverty and malnutrition and reliance on pollinator-dependent crops are highest21,22,23,24.

Ecosystem services result from the actions of individual organisms (for example, the transport of crop pollen by an insect), and the beneficiaries of these services are individual people25,26. However, without studying the sequence of interactions that lead from organisms to people, the concept of ecosystem services can remain abstract and intangible.Consequently, it is challenging to predict the real effects of environmental degradation on human health or to identify practical interventions that enhance ecosystem services in a way that optimizes human health.

In this study, we characterize the plant–pollinator community that underpins human nutrient acquisition in a real-world system and evaluate changes in individual-level diets and income under future scenarios of pollinator population change. We identify features of pollinator taxa that best predict their nutritional importance and identify pathways for enhancing human nutrition through the management of pollination services. Our study takes place in Nepal, where the majority of the population (70%) rely directly on smallholder farming for their nutrition and income, which makes them heavily dependent on local ecosystem services such as pollination27. The smallholder communities in our study region of Jumla District exemplify many of the agricultural, demographic and economic characteristics of smallholder farmers globally and fall within the range of variation reported in a global data portrait of 19 representative smallholder popula