[The unwanted biodiversity: natural disasters in gardens and parks (Dutch elm disease, killer snails etc.)]

babosas biodiversidad biodiversity ceratocystis ulmi damage danemark denmark dinamarca enemigos naturales enfermedades fungosas ennemi naturel fungal diseases gardens jardin jardines limace maladie fongique malezas mauvaise herbe natural enemies parc public public parks rorippa slugs ulmus weeds