What are the Spanish property rules for hedges and trees?

It's common for trees and hedges to grow between terraced properties in residential complexes in Spain, but what happens if they start to become an issue? What does the law in Spain say about this?

What are the Spanish property rules for hedges and trees?
It's common for trees and hedges to grow between terraced properties in residential complexes in Spain, but what happens if they start to become an issue? What does the law in Spain say about this?