Today, in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that parks can reduce surrounding temperatures by up to four degrees Celsius during heatwaves. Interestingly, the cooling effect extends about 100 meters beyond the park boundary, but this depends on the park's size and tree density. Smaller parks, like pocket parks, have a limited impact, while larger ones with mature trees create a more significant cooling corridor. The study also noted that water features, such as ponds, amplify the effect, but they require careful maintenance to avoid becoming breeding grounds for mosquitoes.
❓ According to the lecture, what factor most influences the cooling effect of a park?