ALIEN SHRUBS IN A NATIONAL-PARK - CAN THEY HELP IN THE RECOVERY OF NATURAL DEGRADED FOREST

Both native and alien shrubs spread in areas opened up by cattle-ranching activities. The mosqueta rose, Rosa rubiginosa L., is a particular case of alien species colonization. This rose owes its faster colonization of degraded areas in relation to native species to its rapid and effective endozoic dispersal mechanism, its special vegetative growth and, presumably, the advantages resulting from not having natural enemies. Mosqueta rose bushes have a beneficial effect on the recovery of degraded native forests, as they behave as nurse plants and create a protective microenvironment which favours the spread of woody species from surrounding forests. Recovery of an area subject to fire, over-grazing and overtrampling is a slow process, as native species have not had past interaction with such disturbances. The nurse-crop behaviour of the mosqueta rose shortens this recovery process.