Fig. 6.3 Abandoned terraced fields. Puerto de la Cadena (Murcia) Photo A. Romero-Díaz

Currently, the study of terraced landscapes in Spain requires both a retrospective analysis and an assessment of future scenarios, linked to the regional, national and European policies focused on the management of rural areas. There is considerable scholarly activity in this field and a rich bibliography in both the human and environmental sciences. In this paper, we will try to sketch the main lines of work followed by various research groups and to summarise some of the main opportunities in the near future. Due to the considerable scientific output, we can only quote a tiny sample of the articles published per work teams; we redirect to their publications to expand the concepts treated.

6.2Looking Back, Looking Forward

6.2.1Geo-historical Research

The historical study of Spanish terraced landscapes has shifted from a sectoral approach, attempting to reconstruct ancient farming techniques, irrigation systems and the expansion of terraces, among others (Bazzana and Guichard 1981; Carbonero Gamundi 1984; Barceló 1989; Grimalt and Blázquez 1989), to a cross-cutting vision. These studies led to the formation of multidisciplinary teams.

Among other issues, the teams are interested in interpreting productive spaces (Orejas 2006) in relation to the settlement patterns, population trends, social organisation, climate and land management techniques, etc.; also terrace structures, location preferences, types, materials and functions; the continuous introduction of new crops both in dry lands and irrigated ones or the role of agriculture in landscape transition.

Thanks to these ground-breaking studies, we can trace the history of terraced landscapes in The Bronze Age in eastern Spain—at the beginning of the second Millennium BC in Valencia (De Pedro Michó 1998); in The Iron Age in Denia, Alicante (Gisbert Santonja 2001); or in Roman times in a mining area in the west of the Iberian Peninsula (Ruiz del Árbol et al. 2003) or in the mountainous East (Grau Mira and Pérez Rodríguez 2008). The building and functions of terraces in The Early Middle Ages are well documented in the rural communities in northern Spain, mainly in Galicia since the fifth century (Ballesteros Arias 2010); the sixth century in Bizkaia (Varón Hernández et al. 2012); the eighth century in Asturias (Fernández Mier et al. 2014) and since the tenth century in Álava (Quirós Castillo et al. 2014). The building of terraces has also been studied in al-Andalus (territory under Islamic control since the eighth century): Murcia (Puy and Balbo 2013); mountainous, inland Alicante (Torró 2007); in the “Orchard of Valencia” (Guinot 2008; Esquilache Martí 2015); The Balearic Islands (Glick and Kirchner 2000; Sitges 2006); Andalusia (Malpica Cuello 1996; Trillo San José 2010) and the Ebro valley, north-eastern Spain (Alonso et al. 2014). Terraces in feudal areas have also been studied in depth in Catalonia (Riera and Palet 2005; Retamero et al. 2015), in The Balearic Islands (Kirchner 2012) and the Valencian Community (Torró 2005; Guinot 2009).

Terraced fields spread fast with the dawning of The Modern Age and reached their greatest extension and the highest altitudes at the end of the nineteenth century as a result of population growth and the fact that the country’s incipient industrialisation still required relatively few workers. Andalusia, the Iberian range, The Pyrenees, the western part of The Ebro Valley and, in general, mountainous areas saw farming creep up the hillsides (Cavanilles i Palop 1795; Garrabou 1985; García-Ruiz 1988; Hernández Hernández 1997; Giménez-Font 2008; Boixadera et al. 2016). However, the process reversed from the mid-twentieth century as rural abandonment affected these same areas. The emigration of the young was compounded by the difficulty of mechanising hill farming areas to offset the loss of rural labourers (García-Ruiz et al. 2013).

Looking forward, there is still much interdisciplinary work to do. Among other issues, this includes archaeological and archival research; analysing intensification and extensification in terraced areas in relation to demographic trends and land ownership models; the impact of technological innovations; the links between climate, crops and their diversification. Working together, archaeologists, historians, hydrologists and soil scientists may learn how agricultural techniques affect hydrological and geomorphological dynamics in a watershed over the centuries; the socio-economic and environmental problems derived from shrub clearing in order to enlarge grazing areas and to promote the development of livestock (as tested by

Lasanta et al. 2015); to analyse soil fertility and cultural practices (as tested by Ferro-Vázquez et al. 2015); the long-term assessment of the impact of soil and water conservation techniques on the soil’s organic matter content, and so on. Speaking of techniques, great scope is offered by organic geochemical analyses and radiocarbon dating; to date terraces construction by combining archaeological survey with sampling for luminescence profiling and optically stimulated luminescence (as Kinnaird et al. 2017 have already demonstrated in Catalonia); and to apply statistical modelling techniques.

The cultural importance of these landscapes shows the need to draw up a Catalogue of Spanish Terraced Landscapes, identifying their historical context, the various types of terraces and related constructions, their state of conservation, etc. This task has become affordable because some regions have already published landscape atlases that cover terraced areas, including those for Mallorca (Colomar Mari 2002); Catalonia (Observatori del Paisatge 2008–2016); the Province of Granada (Junta de Andalucía 2014) and the Valencian Community (Generalitat Valenciana 2011). One should also consider drawing up “Best Practice” guidelines for farmers, landowners and decision-makers that take into account the European Union, and national and regional policies bearing on cultural and historical landscapes. This offers new opportunities for responsible tourism in recognising the value of local host communities. The final step should be incorporating terraced landscapes into regional government territorial plans and policies.

6.2.2Eco-geomorphological Studies

There is a long tradition of studies in this field. Since the late 1980s, various teams from Spain’s Scientific Research Council (CSIC) and Spanish universities have analysed the effects of terraces on: soil depth; organic matter content; aggregate stability (Sánchez-Marañón et al. 2002); water repellency (Bodí et al. 2012; Burguet et al. 2016) and bulk density (Seeger and Ries 2008); soil water erosion and run-off generation (Gallart et al. 1994; Durán Zuazo et al. 2005; Cerdà and Doerr 2007; Gaspar et al. 2013; Prosdocimi et al. 2016; García-Ruiz et al. 2017); mineral salts and nutrients; soil compaction and surficial crusts; hydromorphic conditions; the hydrological and geomorphological processes involved (Arnáez et al. 2015); soil infiltration capacity (Arnáez et al. 2017); the influence of soil’s physical–chemical properties on the composition of microbial communities (Zornoza et al. 2009)—in short: soil properties, soil management and soil conservation.

Other issues of interest focus on the consequences of agricultural abandonment in The Pyrenees (Lasanta 1988; Ruiz-Flaño et al. 1992; López-Vicente et al. 2016), Rioja (Arnáez et al. 2011; Lasanta 2014), Catalonia (Dunjó et al. 2003; Poyatos et al. 2003; Olarieta et al. 2008), Mallorca (Reynés et al. 2007), Valencian Community (Ruecker et al. 1998), Andalusia (Douglas et al. 1994; Jiménez Olivencia 2010) and Murcia (Romero-Díaz et al. 2007; Alonso-Sarría et al. 2016; Romero-Díaz 2016).

These researchers work both on erosion modelling and on the analysis of new environmental dynamics when farming stops: their effects in soil organic carbon dynamics (Emran et al. 2012; Nadal-Romero et al. 2016b; Boix-Fayos et al. 2017); vegetation recolonisation; species composition; species diversity; vegetation cover and their effects in soil properties (Marco-Molina et al. 1996; Padilla Blanco 1998; Gallego-Fernández et al. 2004; Pueyo and Beguería 2007; Gispert et al. 2017; Pardini et al. 2017; Romero-Díaz et al. 2017). In connection with this revegetation and the lack of forest management, one should also take into account the greater risk of forest fires and their impact on plant and ecosystem recovery (Vicente-Serrano et al. 2000; Llovet et al. 2009). In some areas, abandonment of farming can lead to the recovery of the geo-ecosystem, with improvements in vegetation and soil quality (Romero-Díaz 2016). These studies have yielded a great deal of valuable knowledge.

Looking forward: Interesting research areas are: (a) the links between terrace location and agricultural abandonment; (b) sediment yield in abandoned areas and long-term soil erosion; (c) tillage erosion, water erosion and soil quality on farmed terraces; (d) the combination of qualitative and quantitative methods to gauge soil erosion in terraced fields; (e) the application of large-scale soil erosion modelling in conservation plans for terraced landscapes; (f) the response of terraced slopes to torrential rain events; (g) analysis of the effects of building terraces on soil properties by crop types; (h) the effectiveness of abandoned terraces as part of afforestation schemes to tackle erosion, etc, last but not least, those studies that focus on soil and water conservation under global change (the first World Conference on the subject took place in Lleida in June 2017).

6.2.3Natural and Cultural Drivers Influencing Mediterranean Landscapes

This section analyses land-use change and societal transformations arising from the appraisal of agricultural land uses, urban expansion, tourism and leisure uses (Plieninger et al. 2016: 210). Driving forces cover both natural and socio-economic issues and include: decreasing attractiveness of farming as a way to make a living in comparison with service industries; the rising impact of second-holiday homes; the job opportunities offered by cities; the low profitability and productivity of farming; the rise of tourism as an economic activity; national and international markets (Lasanta et al. 2017a). In these areas, researchers try to identify primary, secondary and tertiary driving forces, whether intrinsic (influenced by local actions and people) or extrinsic (covering broad processes, such as globalisation, climate change, urbanisation and, of course, European Union policies—especially those bearing on agriculture, the environment, rural development and culture).

Specialists are focusing on past and current land management systems and the processes of change in Mediterranean rural landscapes—intensification