In a very hot, humid climate, most design recommendations would be to plant large canopy shade trees adjacent to streets and roads. And I think that in general, it makes perfect sense. Yet here in Tuscany, for the most part a very hot and humid place, many streets and roads are lined with Cypress (Cupressus sempervirens). They provide some shade and offer an appealing greenness. But they don’t protect the traveler from the blazing sun.
So why plant them and not shade trees? Well, one reason is that they have always been planted here – the power of inertia. They are also very long-lived. Another is that they grow well in the conditions found here, even though they are not native. Their wood is useful. Finally, it may be that they possess a sort of magic, evoking memories of the land and life in Tuscan inhabitants. Few symbols have become as much as the part of the “brand” of a region as have these Cypress. Even in abstract drawings, one knows that these pointy things represent Tuscany, and by extension , the Tuscan dream of tranquility and beauty, of living the good life. So while it may make humans more comfortable to have roads shaded by other types of trees, in this case exceptions must be permitted. Comfort isn’t the end all of the human condition. Symbols are important too. What types of trees are the symbols of your bio-region?