October 2003
From Netherlands Organization for Scientific Research
Rabbit and cow graze together According to Dutch researcher Liesbeth Bakker, rabbits prefer grassland grazed by cows. The rabbits benefit from grass that has been grazed short by the cows as this is of a good quality. Furthermore, this grazing relationship leads to a greater diversity of plant species.The researchers studied a number of plots in the Junner Koeland, a floodplain grassland along the river Overijsselse Vecht. Staatsbosbeheer uses cows to manage the grassland vegetation. However, the numerous rabbits and meadow voles grazing in the area actually consume more grass than the cows. Rabbits appear to have a preference for grassland that has been grazed by cows. Cows graze away the longer vegetation, leaving shorter grass that is easier for the rabbits to eat. Meadow voles avoid such areas of short grass as this does not provide them with enough cover to escape from their enemies. Grazing by both cows and rabbits leads to a great diversity of plants. In particular, prostrate herbs such as self-heal, bulbous buttercup and cat's ear thrive in short vegetation, because then they receive enough light to survive. The greatest diversity of plants is found in places where rabbit digging has resulted in bare soil. Therefore, cows ensure that sufficient light reaches the ground, whilst rabbits ensure good germination spots for prostrate herbs. Finally, Bakker discovered that rabbits are a key factor in determining the extent of shrub cover and whether or not oak seedlings can grow in this. If there are few rabbits, shrub cover can develop in an area grazed by cows and the oak seedlings can root in the shrubs because the shrubs protect the seedlings from the cows. If there are many rabbits, these eat part of the shrub cover and in so doing eliminate the places where oaks can establish. The vegetation on the Junner Koeland is a mosaic of grassland, shrub cover and oak wood. Such a landscape often contains a large diversity of plants and animals. Management of these natural habitats requires a knowledge of how different grazers affect the ecosystem concerned. For further information please contact Dr Liesbeth Bakker (Nature Conservation and Plant Ecology Group, Wageningen University, now at University of Nebraska, USA), tel. e-mail: [email protected]. The doctoral thesis was defended on 23 September 2003. Dr Bakker's supervisors were Prof. Frank Berendse (Wageningen University), tel. 31-317-483-174 and Prof. Han Olff (University of Groningen), tel. 31-503-632-214. The research was funded by the Netherlands Organisation for Scientific Research. |