Pollination decline can significantly impact world’s food supply, US researchers uncover

29 Jul 2024 --- Plants are producing less pollen as a result of climate change, which could have significant implications for the world’s food systems, a group of researchers has found. 

Academics from the University of Texas at Arlington, Virginia Tech and the University of Nevada, Reno, collaborated on the study, “Effects of climate change on Lepidoptera pollen loads and their pollination services in space and time.” 

The study’s findings warn that recent shifts in pollination levels are concerning because reduced pollination can lead to decreased crop yields, which in turn affects food availability and agricultural productivity.

“Shifts in flowering time among plant communities as a result of climate change, including extreme weather events, are a growing concern. These plant phenological changes may affect the quantity and quality of food sources for specialized insect pollinators,” says the research paper.

Significant implications
The group says most prior research has focused on short-term plant-pollinator interactions, which don’t accurately capture changes in pollination services. In the study, they characterized long-term plant-pollinator interactions and identified potential risks to specialized species due to habitat loss, fragmented landscapes, and changes in plant assemblages. 

“We used 21 years of historical data from museum specimens to track the potential effects of direct and indirect changes in precipitation, temperature, monsoons, and wildfires on plant-pollinator mutualism in the Great Basin and Sierra Nevada,” says the paper. 

“We found decreased pollen richness associated with butterflies within sites, as well as an increase in pollen grain abundance of drought-tolerant plants, particularly in the past ten years.”

The Great Basin and the Sierra Nevada Mountain range are home to more than 200 butterfly species, many of which act as pollinators. In the research, 19 sampling sites were selected to understand how insects pollinate plants in the region.

The study points to increased global temperatures and the intensity and frequency of precipitation and wildfires as the causes of the negative impact on pollen diversity. 

Reduced pollination can lead to decreased crop yields, which in turn affects food availability and agricultural productivity.“Our findings have important implications for understanding plant-pollinator interactions and the pollination services affected by global warming,” say the researchers. 

Understanding how insects pollinate 
Dr. Behnaz Balmaki, the study’s lead author and an assistant professor of biology at the University of Texas at Arlington, tells Food Ingredients First that the findings are of great significance due to their potential impact on the world’s food supply.

“A decline in pollination services, as a result of environmental changes such as climate change, affects plant communities by altering plant reproductive phenology, floral resources, and diversity. These changes can trigger population declines in insect pollinators due to reduced food sources, specifically lower flower diversity and quality,” she says. 

“This is particularly significant for agriculture and natural ecosystems, as many crops and wild plants rely on insect pollinators for fruit and seed production. Reduced pollination can lead to decreased crop yields, which in turn affects food availability and agricultural productivity.”

Dr. Balmaki explains that to mitigate the decline in pollination services, strategies such as habitat restoration and conservation, should be deployed. This includes planting native vegetation and adopting pollinator-friendly practices like reducing pesticide use.

Reducing greenhouse gas emissions, enhancing research on pollinator health and monitoring populations and increasing public awareness through policies, are other tactics that could make a difference.

She adds: “Collectively, these efforts can help preserve and improve pollination services, supporting the sustainability of food systems and natural ecosystems.”

Seeing the bigger picture
According to figures shared by the not-for-profit organization Pollinator Partnership, around 75% of crops and about one-third of our food depend on or benefit from animal pollinators. Lora Morandin, associate director at the organization, tells Food Ingredients First that a reduction in pollination puts our food supply “at risk.”

“Many crops already are not getting full pollination and reaching full production due to inadequate pollinator populations. Further reduction in pollinator populations, whether managed honey bees or the thousands of species of wild bees or other pollinators such as moths, flower flies, beetles, wasps, risks further reducing our food production,” she says.Tree fruits, such as berries like blueberries and raspberries, are affected by pollination.

“Many foods are not pollinator dependent such as most grains (corn and wheat), but many of the colorful and healthful foods in our diets that provide us with nutrients and variety are pollinator-dependent or have greater production with animal pollination.”

This includes many tree fruits, such as apples and plums, pumpkins and squash, berries like blueberries and raspberries, chocolate and coffee.

Morandin adds that by creating pollinator-supporting spaces like hedgerows and floral plantings, pollinators can thrive in agriculture. Growers can also adopt integrated pest management strategies, which help protect crops and support beneficial insects like pollinators.

Pollination decline is an issue governments around the world are having to tackle. Last year, the European Commission expressed concern over a decrease in wild pollinating insects in Europe. It produced a new strategy to reverse the trend by 2030, prioritizing boosting pollinator conservation efforts, including mitigating pesticide use’s impact.

By Sade Laja