I'm actually an Arborist, yes, absolutely no use in the republic.
As a matter of fact yes! There are opportunities for your job capacity in the DR. You're just looking in the wrong parts!
You can begin your decent job/pay hunt with an in-person visit to the Jardin Botanico first. There you can gather further contact information to people/places where your skills are wanted/well paid for.
It all goes back to how your capacity really is! If we're talking just cropping evergreens and minor stuff as base experience, you'll have a harder time. If we're talking a good background in actual care and work with certain areas, then the outlook is much better!