Invasive species project, IRL

Killarney park, Ireland's largest national park, has suffered ecological disaster from invasive species. No new trees can succeed in growing there under present conditions. To correct this will require persistent effort.

Perhaps in a few decades it will be possible to develop biological killers that, when released, would eradicate rhododendron and sika deer in Ireland while being somehow unable to spread elsewhere. But that is just speculation. In the absence of that, the eradication of rhododendron will have to be done manually without cease.