Chinese, British scientists help tea farmers tackle climate change

This photo provided by the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences shows tea trees at a tea garden in Fengqing County, southwest China's Yunnan Province, Aug. 7, 2024. (Xinhua)

KUNMING, Nov. 20 (Xinhua) -- Li Shaojuan, a female meteorologist, has been regularly visiting muddy tea plantations in China's southwestern mountainous region over the past decade, in her bid to help local farmers cope with climate challenges.

Li, a professor at Yunnan University of Finance and Economics, visits the plantations in Fengqing and Baoshan counties, Yunnan Province, four to five times a year to do field studies aimed at better climate forecasting and service solutions.

As one of the core origins of tea trees in the world, Fengqing was part of the ancient Tea Horse Road, a trade route dating back to the Tang Dynasty (618-907), and features tea gardens that are harvested three times a year -- in spring, summer and autumn.

Climate change is becoming a growing concern in terms of both the quality and yield of its tea crops. "Especially in spring, the likes of cold snaps, hail and drought make the most precious spring tea period unproductive," said Zhang Guoqin, who runs a local tea company, adding that in summer, excessive rainfall fosters wet diseases, while higher temperatures and humidity fuel the spread of pests.

"We interviewed local tea farmers, and distributed questionnaires to them, hoping to understand their specific needs in detail," Li said. The scope of the interviews also included consumers, tea processing factories, refining factories, dealers, trade companies and more.

Li is among a group of Chinese and British atmospheric scientists who aim to use their expertise to provide tea farmers with more accurate weather forecasting services -- and help them better adapt to frequent meteorological disasters.

These scientists have developed mathematical models based on data revealing meteorological factors that affect tea tree growth and tea production. "We need to understand how these factors influence tea cultivation and production before determining what type of weather forecasting to provide," Li explained.

Annual predictions of both tea yield and quality can guide farmers in purchasing agricultural insurance to protect their income and ensure a stable market supply. Subseasonal-to-seasonal forecasts can help farmers determine the optimal timing and strategies for activities such as harvesting fresh leaves, initial processing, fertilization, and pest and disease management, she said.

"We hope our predictions will give farmers insights into climate trends and anomalies, helping them plan production and field management to ensure consistent tea harvests," Li added.

This photo provided by Yunnan University of Finance and Economics shows Chinese and British scientists discussing issues in a tea garden in Fengqing County, southwest China's Yunnan Province, Nov. 10, 2024. (Xinhua)

However, this process is far from straightforward. Li revealed that inconsistencies between their initial research and real-world conditions often require them to revisit their models or conduct additional field studies.

"We're not just studying data -- we're studying living tea trees," Li said. "It's a challenging process, but also one full of joy, because scientific research is about the constant pursuit of truth."

Li's work is part of a larger collaboration between China and the UK. The Climate Science for Service Partnership China (CSSP China) project, launched in 2014 by the UK Met Office, the China Meteorological Administration, and the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences, aims to build climate-resilient services for economic and social development.

With more countries facing extreme climate events, there is an urgent need to improve international collaboration and build services to enhance society's resilience in the face of the impacts of climate change, Rowan Sutton, director of the UK Met Office Hadley Centre for Climate Science and Services, said at the CSSP China annual workshop held early this month.

So far, this initiative has developed several climate service prototypes, including seasonal rainfall forecasts for the Yangtze River Basin, the maize yield in northeastern China, and the tea industry in Yunnan Province.

Li's research in Yunnan Province is being complemented by similar studies in the UK. "We're conducting case studies in Devon and Scotland, and we hope to complement our research by doing comparative studies between the two countries, where tea trees are grown in different environments," said Stacey New, an expert from the UK Met Office.

The team has found that the impacts of climate change on the tea industry vary widely depending on location, elevation and farming practices.

"Therefore, there is no one-size-fits-all solution for climate change adaptation in the tea sector, and climate services need to be tailored and customized to the specific circumstances and needs of the stakeholders," said New. The team's research results have been detailed in a paper recently published in the journal Advances in Atmospheric Sciences.

"The CSSP China project is a good example of Sino-British cooperation to jointly address climate change," said Zhou Tianjun, deputy director of the IAP, adding that the experience gained could be expanded to other tea-growing regions and may even apply to other crops like coffee and sugarcane.

In addition to weather forecasting, Li has also been looking into ancient farming practices in her quest for answers. She recently discovered an ancient tea plantation in southwest China, where the tea trees are hundreds of years old but still produce harvestable leaves of good quality. What sets this plantation apart is its natural and biodiverse ecosystem, which has made it more resilient to climate extremes.

For example, among the diverse tree species in the ancient plantation, the alder tree plays a key role as a nitrogen-fixing plant, enhancing soil fertility. Additionally, the ground beneath tea trees there is typically covered with grass and a thick layer of humus, which helps retain moisture and regulate temperature, enhancing tea trees' resilience to adverse weather conditions, she said.

Li believes this ancient approach could hold valuable insights for modern tea farmers. "The ancient tea garden is an ecosystem that resists climate change," she said. "I hope to integrate this wisdom into today's tea cultivation practices to help more farmers adapt to climate challenges."

In Chinese character glyphs, the word for tea depicts a person between a blade of grass and a tree, symbolizing the harmony between humans and nature. "Perhaps the answers to many of our scientific questions are hidden in these ancient practices and the wisdom of the ecosystem," Li speculated.

"A closer integration with nature could be the key to addressing climate change in the future," she added.