Today in our environmental science lecture, we're discussing urban green spaces. A recent study in Melbourne found that increasing tree canopy cover by 20% could reduce summer street temperatures by up to 4 degrees Celsius. However, the researchers noted that this effect is strongest in residential areas with low-rise buildings, not in high-density city centers. They also emphasized that maintenance costs are often underestimated, and recommended using native species which require less water. Interestingly, community involvement in planting programs was shown to increase the survival rate of young trees by nearly 30%.
❓ According to the lecture, what did the study in Melbourne conclude about tree canopy cover?
A. A. It reduces temperatures most effectively in dense city centers.
B. B. It has the greatest cooling effect in low-rise residential areas.
C. C. It requires high maintenance to be effective.
D. D. It only works with non-native tree species.
✅ 正确答案
B. It has the greatest cooling effect in low-rise residential areas.