See from the function results, it is best for deciduous broadleaf tree on the potential of absorbing carbon-releasing oxygen, decreasing temperature and purifying SO2; next is fewer shrub and coniferous tree, grass is the worst.

• 从作用效果来看，落叶阔叶树类的吸碳放氧、降温效果和SO2的净化潜力最佳，其次为花灌木和针叶乔木树种，草类最差。