Historical Use Data

Some traditional practices such as grazing have been crucial for promoting ecosystem diversity, resilience, and heterogeneity. However, the effects of ungulates on ecosystem services vary widely and depend on the context. One of the most influential factors determining these effects is their population density, including both wild and domestic ungulates. Currently, in Doñana National Park, domestic and wild ungulates coexist, reaching high densities in some estates. In many areas of the park, Mediterranean forest regeneration is limited due to declining water tables, pest and pathogen impacts, and the effects of large ungulates. The poor regeneration of these forests poses a threat to the biodiversity they support and the ecosystem services they provide. In this study, we make use of a set of exclosures constructed 15 years ago - that gradually became more permeable to the ungulates they were designed to exclude- to study the short- and long-term impact of ungulates on Mediterranean woodland vegetation in Doñana National Park. Specifically, it examines three key aspects: (1) plant damage and consumption, (2) sapling density (i.e., recruitment) and (2) plant size (i.e., establishment and growth). We observed significant levels of damage and browsing on branches when domestic herbivores were present in moderate or high relative abundances, showing a linear effect. In contrast, the impact of wild herbivores increased with their abundance but tended to saturate at higher densities and, in some cases, even decreased. We did not observe clear or consistent effects of herbivores on the saplings density of various species, likely due to the low number of saplings found (n = 62), which may suggest very low recruitment of the species studied within the enclosures. Regarding the establishment and growth of juvenile plants, both the average height and canopy size, as well as their variation, were generally lower in areas with a historically higher presence of herbivores. With climate change, the adverse effects of herbivory on Mediterranean forest ecosystems, as observed in this study, could become more severe. It is essential to continue researching the ecological interactions between herbivores and the park's ecosystems. This knowledge can be applied to the development of management strategies to balance livestock production, wildlife conservation, and the resilience of Mediterranean ecosystems to climate change.