雅思听力

🎧 Listening Transcript

Today in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that adding trees to city streets can reduce local temperatures by up to 3 degrees Celsius during summer. However, the researchers noted that this cooling effect depends on tree species. Broad-leaf trees with dense canopies, like oaks, provide more shade than narrow-leaf varieties such as eucalyptus. The study also highlighted that green roofs, while effective for insulation, have less impact on street-level heat. Interestingly, the data showed that parks larger than two hectares are significantly cooler than smaller pocket parks, which tend to be warmer due to surrounding buildings.