Answer:
Un biólogo ecuatoriano ha descubierto venticinco especies nuevas de árboles.
Step-by-step explanation:
The present perfect is a tense used to indicate an action that has started in the past but continues to this day, the sentence that we need to create is talking about an Ecuatorian biologist that has discovered 25 different species of trees, in this case since he is still discovering plants we would use the present perfect tense, in spanish since it is talking in the singular third person we would use "Ha descubierto" to say that he has discovered.