Premature Leaf Fall in Mid-Summer Alarms Zagreb Residents
Experts explain it's a natural response to prolonged drought and high temperatures, but warn of dangers if heatwaves persist.
Experts explain it's a natural response to prolonged drought and high temperatures, but warn of dangers if heatwaves persist.
Zagreb's parks and tree-lined streets have looked like autumn has arrived in recent days. Yellowing leaves drying up and falling prematurely from canopies have caused concern among many citizens, but experts have an explanation for this unusual phenomenon in the middle of August.
According to Jasna Molc, head of the Ecology and Forest Protection Department at Croatian Forests, this is a completely natural defensive reaction of trees to high temperatures and prolonged heatwaves. "What skin is to humans, leaves are to trees," Molc told RTL Danas. She added that just as people reduce activity and slow down during dehydration and extreme heat, trees similarly reduce the surface area through which they lose moisture, hence they shed leaves.
DHMZ agrometeorologist Jasmina Dobranić confirmed this assessment, noting that premature leaf fall is not a sign of early autumn but a consequence of heat and drought stress. "Plants are under the influence of very high air temperatures. We've measured maximum values above 30 degrees, and there's also a lack of soil moisture, so plants shed some leaves to conserve water and energy," Dobranić explained.
Greenery in Zagreb is regularly watered, and one watering cycle for all trees in a city district takes about ten days. According to data reported by Dnevno.hr, a single tree requires between 80 and 120 liters of water per watering. Smaller shrubs need 15 to 20 liters, while larger ones need 25 to 30 liters. During extreme heat, flower beds require up to 35 liters of water per square meter weekly, while lawns need up to 30 liters.
Experts emphasize that the current leaf fall does not pose a serious threat to trees. "We don't need to worry about this phenomenon for now because trees will overcome it without any problems," Molc said. However, she also warned of potential long-term consequences. "It would be concerning if such situations and prolonged heatwaves occurred multiple times. Because then the tree would physiologically weaken and become more susceptible to other plant diseases and pests," concluded the head of the Ecology and Forest Protection Department.
