Study on the effect of cattle grazing on the mediterranean landscape of els Ports Natural Park

Abstract

In recent decades, the European Union has been favouring, by various agricultural and environmental policies, farming practices focused not only on productivity but also on environmental management. These policies have led to an increase in the number of herds of bovine cattle to the detriment of small ruminant flocks. At the same time, there is an increasing interest in the potential role of livestock in reducing the bush encroachment process and wildfire risk. However, there is little empirical evidence to support its effectiveness.The aim of this study was to evaluate the effect of different cattle types (beef and bullfighting stock) on the evolution of landscape structure and the possible control of bush encroachment in Els Ports Natural Park (northeastern Iberian Peninsula). We evaluated the potential effect by two different approaches applied on the herd scale and the spatio-temporal scale. Specifically, we studied the consumption of woody species by the two cattle types during the summer and evaluated changes over time in forest, shrub and grassland cover before and after the introduction of the cows. The diet analyses show a clear preference for grass species (especially Brachypodium sp.) but with significant differences between cattle breeds. Bullfighting cattle consume more woody plants (e.g., Erica multiflora) than beef cattle. Likewise, landscape structure analyses reveal significant changes over the time with cattle. Shrub cover has decreased whereas forested areas show the opposite tendency. The decline in bush cover, however, seems to be more closely related to natural vegetation succession than to cattle browsing. Therefore, cattle exert a negligible effect on bush encroachment. The fire risk alone may be partially reduced by the preferential consumption of easily inflammable grass species. In the light of these results, we suggest a re-design of management practices with the aim to reduce bush encroachment and fire risk.

Keywords: cattle grazing, diet selection, livestock management, fire hazard, bush encroachment, forest, microhistological analysis, ruminants.