The ONF (National Forestry Commission) has involved Vanilla growers (over 200 in St Philippe) in the ecological restoration of some of the most overgrown plots of forest in the Biological Reserve, by granting them concessions. The concessionaires have carried out extensive work to control invasive plants (in particular Schinus and Psidium), while retaining native trees to act as stakes for the Vanilla. Other native species have also been preserved, and the disappearance of invasive species has encouraged their return to the undergrowth (ferns in particular). In these conceded plots, native species once again dominate the forest canopy, while allowing Vanilla production in the undergrowth. The undergrowth is maintained by the concession holder, in accordance with a set of specifications, and monitored by ONF agents. This system helps to control invasive species such as Clidemia hirta and limit their invasion of the neighboring, well-preserved relics.