I’m sure it does vary—my impression is that N fixing trees in particular are going to have higher N levels in the leaves they drop but I’m sure it varies by species as well.

But from my experience, most urban shade trees don’t really need to be fertilized unless they are exhibiting symptoms of nutrient deficiency—and even then, this is often a symptom of poor soil and root health overall more than a specific lack of a nutrient. Most urban soils tend to be fairly high in nutrients due to air pollutants, excess fertilizers, pet feces, etc. I’m sure this can also vary by soil type and climate, but it’s true in most areas I’m familiar with.