Beijing warns of heavy catkin season on way

Beijing issued a second forecast for poplar catkins on Thursday, which is expected to last approximately 20 days, as city government departments carry out a range of measures to solve the fluffy problem and minimize its impact on residents' lives.

Following the first such forecast for poplar catkins on April 7, the second period is set from April 18 to May 7, according to the Beijing Gardening and Greening Bureau and the city's weather bureau.

Entering spring, many provinces and municipalities in northern China, including Beijing, are experiencing a high incidence of poplar catkins.

Poplar trees are widely distributed across China, ranging from plains to altitudes of 4,800 meters. In addition to extensive planting of poplar trees in the north, cities in the south such as Shanghai, Nanjing and Hefei also extensively utilize poplar trees in urban greening.

However, the catkin season of poplar trees in the south coincides with the rainy season, where rainwater has a flushing effect on catkins, resulting in a significantly smaller impact on daily life.

In Beijing, it is usual to have spring rain before and after the onset of catkin season, which moistens the ground and roads. However, this year, the expected rain did not arrive on time, leading to a more severe catkin issue compared to previous years.

"Up to 12 departments in Beijing are closely collaborating to carry out high-standard forecasting and comprehensive measures to deal with the catkins, and to implement prevention and control measures," said Zhang Bo, deputy director of the greening bureau's technology department.

The floating catkins come from female plants, and in response, Beijing has been scientifically breeding and promoting male poplar trees in recent years, Zhang said.

In collaboration with Beijing Forestry University, the bureau has introduced five new varieties suitable for growing in Beijing that do not produce catkins.

"Currently, the city has bred and reserved more than 200,000 non-catkin poplar seedlings, with over 50,000 already applied in the renewal and transformation of old and diseased catkin-producing female poplar trees," he said. "We plan to further promote the application of these new types."

Liu Yong, a professor at Beijing Forestry University, said one of the five new non-catkin varieties originates from a male poplar tree in southern Beijing's Daxing district that is about 200 years old.

"This variety has a straight trunk and a broad branch spread, exhibiting excellent performance in the Beijing area with strong adaptability and stability," Liu said.

"The successful breeding of this variety not only protects and utilizes Beijing's ancient poplar tree resources but also provides an effective way to alleviate the catkin problem that has been troubling Beijing residents for years."

Spring is also a season in which an increasing number of people suffer from allergies.

"The main reason is the blooming of spring flowers," said Wang Xueyan, director of the allergy department at Beijing Shijitan Hospital affiliated with the Capital Medical University. "As the temperature gradually rises, a large amount of allergenic tree and flower pollen is dispersed in the air, leading to pollen allergies.

"There is indeed an increase in the number of people who started to get allergies this year. Sudden pollen allergies are also related to the body's immune status. For example, excessive fatigue and poor emotional states can lead to immune dysfunction, which triggers or exacerbates allergic reactions."