China’s capital maps its willows and poplars in fightback against annual catkins blizzard
- Hundreds of forestry students use aerial photographs to identify problem areas
Beijing has mapped its female poplar and willow trees to try to contain catkins that descend on the city each spring.
The Chinese capital has been blanketed by catkins, the trees’ fluffy seeds, each spring for decades. The trees were planted in the 1960s and 1970s as a cheap, easy-to-maintain and quick-growing way to make Beijing greener.
Female trees look very similar to the males. The capital’s parks authority began a survey in 2017 to find out where female willows and poplars were planted so it could neutralise the catkins and go some way to sparing citizens weeks of sneezing and watery eyes as pollen spread, Beijing Youth Daily reported on Monday.
Aerial photography was used, with urban areas inside the Fifth Ring Road – where most of the city’s population lives – divided into 2,866 grids, each of 250,000 square metres, Qin Yongsheng, an official with the Beijing Gardening and Greening Bureau, said.
Three hundred students from Beijing Forestry University trained to identify the female varieties plotted the trees’ locations by species and growth, and marked them for follow-up action if required.