Stone-walled terraces restoration: conserving biodiversity and promoting economic functions of farmlands in Lebanon
From Firenze University Press Journal: Journal of Agriculture and Environment for International Development (JAEID)
Alessio Martinoli, University of Insubria, Department of Theoretical and Applied Sciences, via Dunant 3, 21100 Varese, Italy
Pedro Regato, Indipendent consultant, Madrid, Spain
Farah Abdel Samad, Laboratoire Biodiversité et Génomique Fonctionnelle, Faculté des Sciences, Campus Sciences et Technologies, Université Saint-Joseph, Beirut, Lebanon
Lara Kanso, Al-Shouf Cedar Society, Lebanon
Nijad Saed Eddine, Al-Shouf Cedar Society, Park House, Maasser el Shouf, Lebanon
Mirko Panichi, Istituto Oikos, via Crescenzago 1, 20134 Milan, Italy
Alessandra Gagliardi, University of Insubria, Department of Theoretical and Applied Sciences, via Dunant 3, 21100 Varese, Italy
Lina Sarkis, Al-Shouf Cedar Society, Park House, Maasser el Shouf, Lebanon
Nizar Hani, Al-Shouf Cedar Society, Park House, Maasser el Shouf, Lebanon
Agricultural smallholder terraces are peculiar features of Mediterranean cultural landscapes, enabling crop production in dry environments and steep slopes (García-Ruizet al., 2020; Tarolliet al., 2014). Terraced croplands have thousands-year old tradition in the Mediterranean basin and are widespread across all Mediterranean cultures (Blondel, 2006; Kladniket al., 2017). Twelve UNESCO World Heritage Sites and two FAO’s Globally Important Agricultural Heritage Systems (GIAHS) which feature terraced landscapes are found in the region. Terraced landscapes are typical examples of social-ecological systems which retain ecological functionality while providing several ecosystem services (ES) (Nieto-Romeroet al., 2014). Beside food provisioning, ES provided by terraced landscapes include the reduction of soil loss, the increase of rainfall retention, the increase of plant biomass, the enrichment of the soil, the mitigation of fire, floods and desertification risks.
Most notably, terraced landscapes ultimately represent a valuable adaptation strategyin face of the climate warming. Two main types of terraces are used in the Mediterranean region, namely earth embankments and dry stone terraces, with possible use of mixed types (Cicinelliet al., 2021). Lebanon features dry stone walls as vertical elements to create horizontal strips of land cultivated with tree crops, such as mulberry (historically used for silk production), vines, olives, figs, walnut and, most recently, apple and cherries (Zurayk, 1994). In the last decades, agricultural transformations in the Mediterranean are led by two opposite drivers, i.e. the intensification of farming practices and the abandonment of economically marginal croplands (Debolini et al., 2018; Lomba et al., 2020; Otero et al., 2015; Plieninger et al., 2016; Reynoldset al., 2014). Lebanese terraced farmland has been affected by both drivers. In fact, after the WWII considerable migration of the population from the countryside to the coastal cities caused the abandonment of less accessible terraces. The abandoned terraces have suffered two different types of processes: (i) soil erosion due to the lack of maintenance of the stone walls and steep slopes, and (ii) fast secondary forest colonization on more stable terraces where the soil has been maintained, although the accumulation of dry biomass increases the risk of fires (Abdallah, 2012). Similar pattern are found across Mediterranean countries (Brunoriet al., 2018; Heideret al., 2021; Modicaet al., 2017; Rühlet al., 2006).
According to the time of abandonment and the stability of the slopes, different deterioration stages are seen in the terraces. In some cases, stone walls have completely collapsed causing erosion and hindering colonization by serial shrubby vegetation. In other cases,with more stable slopes, the terraces remain invisible as they have been colonized by very dense secondary pine forests (Pinus brutia) and mixed communities of oaks (mainly Quercus infectoria, and to a lesser extent Q. coccifera) and pines. This phenomenon has relevant consequences on biodiversity and environmental risks. On one hand, dry stone-walls, together with other farmland microhabitats linked to sustainable farming practices (e.g. scattered trees in farmland plots, synanthropic vegetation such as the segetal plant communities of cultivated habitats, ruderal vegetation dominated by thistle-type species along cropping borders, roadsides, and disturbed lands, the vegetation of water ponds or water lines crossing terraced crops, and patches of woody vegetation surrounding terraced crops), represent themselves an important microhabitat which enhance farmland biodiversity (Solomouet al., 2020). On the other hand, farming practices have been usually intensified with the use of pesticides, fertilizers, irrigation, ploughing, the use of herbicides for the suppression of synanthropic vegetation, and the cementation of the stones of the walls destroying the habitats of their interstices. Farming intensification is universally acknowledged as one of the main threats to farmland biodiversity (IPBES, 2019), including in the Mediterranean basin (Henle et al., 2008; José-Maríaet al., 2010).
The transition from low-input to intensive practices in Lebanese terraced croplands started in the 1970s, after a grape phylloxera infestation affected vineyards, forcing landowners to shift to apple and cherry production, which require more intensive farming practices (Corrieriet al., 2021). Stone-walled terraces are featured prominently in the Shouf Biosphere Reserve (SBR), the largest protected area of Lebanon, which corresponds to the 5% of the country area. In the western slope of the Shouf range (included in the Shouf District) terraces are present over the 10% of the land (Corrieri et al., 2021). In the early 1990s, almost 66% of terracesn the area were already abandoned (Zurayk et al., 2001). The restoration of abandoned terraces plays a critical role in terms of enhancing ecosystem services to sustain both biodiversity and human livelihoods. In 2016 the SBR started a restoration program of abandoned terraces within the framework of a large-scale Forest and Landscape Restoration initiative, covering the 50,000 ha of the SBR (Hani et al., 2017, 2019, 2021). Overall, more than 150 ha of degraded dry-stone wallsterraced were successfully restored. The restoration of dry stone-wall terraces in the SBR also included interventions for the maintenance and recovery of marginal habitats linked to the agriculture terraces, such as hedges, tree and shrub shelters, isolated trees, ruderal vegetation along roads, consistently with the FLR principles. Restored terraces have been being farmed sustainably, with low-input agricultural practices and high diversity of crops (fruit trees, olives, aromatic plants, vegetables).
DOI: https://doi.org/10.36253/jaeid-13012
Read Full Text: https://www.jaeid.it/index.php/jaeid/article/view/13012
