Today, in our environmental science lecture, we're discussing the impact of urban green spaces. A recent study in Melbourne found that increasing tree coverage by 10% can reduce local temperatures by up to 2.5 degrees Celsius during summer. However, the researchers noted that this effect is stronger in neighborhoods with taller buildings, because shade and evapotranspiration are more concentrated. The study also highlighted that parks with diverse plant species attract more birdlife, but require more water. Interestingly, the cost of maintaining these spaces was lower than expected, especially when using native plants, which need minimal irrigation. So, the key takeaway is that strategic planting, not just quantity, matters most for cooling.
❓ According to the lecture, what factor most significantly influences the cooling effect of urban green spaces?