Citation
Schmitz, Anjia and López Sánchez, Aida and Roig Gómez, Sonia and Isselstein, Johannes
(2016).
Grazer effects on plant species richness and tree debarking within orchard pastures.
In: "26 th.General Meeting of the European Grassland Federation", 4 a 8 de Septiembre 2016, Trondheim, Noruega. ISBN 978-82-17-01677-9. pp. 642-650.
Abstract
Orchards are traditional agroforestry elements in agricultural landscapes and valuable for nature
conservation in Europe. However, their diversity is endangered due to farmland intensification or
abandonment. Grazing management promotes plant species diversity but grazers are suspected to harm
trees through debarking. We studied 42 orchards within the Rhenish uplands (Germany) and compared
horses, cattle and sheep grazing. We analysed how grassland diversity is promoted by the presence of trees
and modified by grazing management, as well as how grazers may impact trees. Plant species richness
benefited from tree presence, but was not affected by tree-cover and only slightly by grazer species,
whereas grazing intensity showed significant negative effects. All grazer species significantly increased
recent debarking in the absence of individual tree-protection. Therefore, maintaining species diversity
and long-term tree persistence in orchards does not primarily depend upon grazer species, but more
especially on grazing intensity and tree-protection.