Today in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that adding parks and tree-lined streets can reduce local temperatures by up to 4 degrees Celsius during heatwaves. This cooling effect occurs because trees provide shade and release moisture through evapotranspiration. However, the researchers noted that the benefits are strongest when green spaces are connected, forming corridors that allow cool air to flow through the city. They also emphasized that maintenance is crucial, as poorly managed parks with dry grass can actually increase heat reflection.
❓ According to the lecture, what condition maximizes the cooling effect of urban green spaces?