Effects of the overabundance of wild ungulates on natural grassland in Southern Spain

Increases in the deposition of nitrogen affect biodiversity and the composition of natural vegetation. A significant amount of this nitrogen may originate not only from intensive agricultural and livestock farming, but also from wild ungulates whose abundance and area of distribution are currently increasing in the Iberian Peninsula. In this study we have estimated the abundance of two species of wild ungulates (red deer and wild boar) and the amount of nitrogen contained in their droppings and in the grass. We have also recorded the herbaceous community. The results show that the density of these ungulates is positively correlated to an increase in the grass nitrogen, which adversely affects the percentage of leguminosae in pastures. These results suggest that high densities of ungulates may be affecting plant communities by increasing the amount of nitrogen as a result the deposition of droppings. The current system of big game management should therefore be reviewed to make it compatible with the conservation of plant communities and small herbivore species that may be negatively affected by changes in pasture quality and quantity.