Le spine aiutano le rose perché scoraggiano gli erbivori e l'essere calpestati, specialmente quando la pianta è giovane, e perché possono aiutare la pianta ad aggrapparsi ad altre superfici e ad 'arrampicarsi', come nelle rose rampicanti.

After exhaustive (2 min) on-line search, I found that the prickles (more shortly) on roses protect against, primarily, mammals that would want to eat them, particularly, the hips. Anything from a mouse and larger find them an obstacle. I know they’ve left impressions on me. Roses seem to prefer birds to scatter their seeds in the wild.

I won’t go into the difference between a thorn and a prickle, or a spine or the other pointy protuberences plants have come up with. Read more here…Thorns, spines, and prickles - Wikipedia