The Spanish dehesas: a financial appraisal of holm oak (Quercus ilex) regeneration

Abstract

Spain’s 2.25 million hectares of dehesa woodlands are managed for livestock, fuel wood and charcoal production. They also provide wildlife habitat, outdoor recreation, aesthetic values and are considered to be of outstanding ornithological interest. However, in recent years, in an attempt to raise farm profitability, farmers have increased the number of livestock grazing on their land. Concern regarding poor holm oak has led policy makers in Spain to investigate whether or not domestic herbivory threatens the holm oak population. An ecological-economic model is constructed from four case-study sites in Extremadura. The model is used to define grazing thresholds commensurate with the long-term sustainability of holm oak. Results indicate that farmers under highly intensive grazing regimes (> 2.0 Ewe Equivalents/ha) have a negative impact on natural regeneration. However, results also show that it is unlikely that farmers engaged in moderately intensive livestock management regimes (< 1.5 EE/ha), will lead to the demise of holm oak. The model is also used to determine changes in farm income brought about by potential restrictions in livestock management strategies for complying with grazing thresholds. This information is then used as likely payments that a farmer would require in compensation for the supply of environmental goods associated with holm oak habitat. These results could be used to guide conservation practices and contribute towards the development of agri-environment policy associated with dehesa agro-ecosystems.