Where slugs may safely graze

摘要

Grazing animals mow meadows to useful effect. From the results of experiments on newly established grassland, one such grazer, the little-considered slug, evidently has a big and beneficial influence on plant diversity. Large mammalian grazers are allies of the conservation biologist. Sharp incisors, grinding molars and selectiveness in their choice of vegetation have made sheep, cattle and horses invaluable for grassland managers concerned with enhancing diversity or encouraging particular plant species. But what of invertebrate grazers? Grasslands support large populations of small herbivores, from aphids to grasshoppers: what role do these lesser grazers play in the development of the plant composition of grassland habitats? This question lies at the heart of an experimental study, conducted by Buschmann and colleagues, and published in Functional Ecology, on the impact of slugs on the development of an area of sown grassland near Zurich in Switzerland.