Dehesas as high nature value farming systems: a social-ecological synthesis of drivers, pressures, state, impacts, and responses

Abstract

Dehesas and montados are Mediterranean agroforestry systems characterized by scattered oak trees with an understory grazed extensively by livestock and, in some cases, periodically cropped. A long history of traditional management practices has created an open woodland widely recognized for rich biodiversity and multiple ecosystem services. Concerns about challenges to their longterm viability have motivated many disparate scientific studies in recent decades. We provide a synthesis of this growing body of international literature, focusing on the links between land use and management practices, biodiversity, and policy, from a "high nature value farming systems" perspective. The present review comprises 128 empirical studies carried out in Spain and Portugal. Conservation trends were assessed according to categories adapted from the DPSIR (Drivers -Pressures -State -Impacts -Responses) framework. Socio-cultural factors, economic dynamics, and agricultural policies were found to be key drivers of change, resulting in intensification of livestock production and land use simplification, among other effects. Insufficient tree regeneration and a broad range of other factors were identified as pressures that have often negative impacts on biodiversity and ecosystem services, moving the system away from its archetypical ecological state. A variety of management and policy responses were suggested, ranging from specific conservation techniques to landscape-level initiatives. Ecosystem components and management practices were typically studied separately, and mainly from an ecological science perspective, while inter-and transdisciplinary approaches including examination of the role of people were less common. This points to a need to move from single-topic to landscape-level approaches with a broader integration of different disciplines and perspectives.

Inclusive conservation and the Post-2020 Global Biodiversity Framework: Tensions and prospects

“…15,16 Most of these farming systems in Europe are associated with a long history of shaping and maintaining semi-natural habitats of high biodiversity. 17 In contrast, protected area management, which began in the United States, was strongly influenced by the Wilderness movement, underpinned by values for ''pristine'' nature. This movement was paralleled by resource management practices focused on wise use and sustainable yield driven by utilitarian concerns (e.g., access to game, mining, and forest production).…”

250-Year reconstruction of pollarding events reveals sharp management changes in Iberian ash woodlands

“…This period matches with the rural exodus and urbanization of the society, and the strong upsurge of Spanish economy (De la Torre and García-Zúñiga 2014), with a rapid internal population reorganization that transformed radically rural landscapes driving a rapid abandonment of traditional activities (MacDonald et al 2000;Rozas et al 2008;Lasanta et al 2021). As a consequence, many farmers and landowners abandoned traditional farming practices highly valuable for cultural heritage conservation (Plieninger et al 2021). Albeit Madrid province received a huge number of immigrants, this phenomenon was concentrated in the capital and its conurbation.…”

“…Nowadays, the Iberian Peninsula hosts the largest extension of pollard tree landscapes in Europe, with more than 3 million hectares of pollard woodlands known as dehesas (Moreno et al 2007). Dehesas woodlands mainly dominated by Quercus ilex L. and Q. suber L. are widely represented in the low-populated rural landscapes of western Spain and Portugal (Pulido et al 2001;Bugalho et al 2018;Plieninger et al 2021). However, relatively large and well-preserved pollard woodlands of narrow-leaved ash (Fraxinus angustifolia Vahl.)…”

Multiomics Molecular Research into the Recalcitrant and Orphan Quercus ilex Tree Species: Why, What for, and How

“…Within the genus, Q. ilex ( Figure 1 ) is the dominant tree species in the Mediterranean forest and the agrosilvopastoral ecosystem “dehesa” (Spain) or “montado” (Portugal) ( Figure S1 ) [ 14 ]. Hence, in Spain, out of the 15 Mha of forested area (50 Mha total Spanish land surface), 30% (4.5 Mha) corresponds to Q. ilex , mostly in “dehesas” forests (3,1 Mha; [ 15 , 16 , 17 ]). The most profitable product of Q. ilex is the acorns, which constitute the food of the Iberian pig, from whom high-quality meat products are created [ 18 , 19 ].…”