Using an objective and probabilistic model to evaluate the impact of different factors in the dehesa agroforestry ecosystem

The dehesa is a characteristic ecosystem in the southwestern part of the Iberian Peninsula. It has a high environmental value, and also a great importance from a social, cultural and economic point of view in those geographical areas in which exist. However, nowadays the natural values and the sustainability of this ecosystem are seriously threatened. With the aim of identifying useful tools to help in the decision making process to better manage the dehesa ecosystem, a set of surveys was performed to detect, classify and analyze those different problems that can affect it and, later, the responses were treated using the Rasch probabilistic model. Thus, surveys conducted in each municipality were related to the considered topics and vice versa. 119 surveys containing 68 topics of different nature, such as general threats affecting pasture, woodland, new technologies, fire, industry, commercialization, environment, rural tourism, cork, wood and hunting, were recovered from 23 municipalities located around the Monfragüe National Park, in the Autonomous Community of Extremadura (southwestern Spain). After processing them with the Rasch methodology, it is evident that the topics of major interest as the respondents indicated are ageing and lack of woodland regeneration, oak decline due to one of the most important fungal disease called “la seca”, and the issues related to industrialization and commercialization; topics related to the environment in general, e.g. wildfires or uncontrolled slurry discharges, are not perceived as essential. It was also obtained that the data fit the model reasonably, without important misfits, but some topics were found redundant, which should be taken into account to improve the surveys. The Rasch model constitutes a fundamental tool to better understand the relationships between those factors that exert an important influence in the dehesa ecosystem, helping to identify the threats and topics neglected by the owners but necessary to obtain a more cost-effective and environmental-friendly field management.