Landscape changes and land degradation in the subalpine belt of the Central Spanish Pyrenees. (March 2021)

• Record Type: Journal Article
• Authors: García-Ruiz, José M.; Arnáez, José; Sanjuán, Yasmina; López-Moreno, Juan I.; Nadal-Romero, Estela; Beguería, Santiago
• Is Part Of: Journal of arid environments. Volume 186(2021)
• Publication Date: 2021-03
• Subjects: Subalpine belt -- Deforestation -- Geomorphic processes -- Shallow landslides -- Geomorphic diversity -- Pyrenees; Arid regions ecology -- Periodicals; Arid regions -- Periodicals; Écologie des régions arides -- Périodiques; Régions arides -- Périodiques; 577.54
• DOI: 10.1016/j.jaridenv.2020.104396
• Languages: English
• ISSNs: 0140-1963

Abstract

Abstract: As with other mountain areas in Europe, the subalpine belt of the Central Spanish Pyrenees (approximately 1600–2200 m a.s.l.) has undergone constant deforestation since the Neolithic era and particularly during the Late Middle Ages, in favour of livestock management and grazing in summer. This furthered the rise of transhumance between the lowlands and the highlands. The abrupt change in land cover triggered a variety of geomorphic processes and landforms that partially contributed to land degradation and an increase in erosion and sediment yield: shallow landslides, solifluction lobes, soil creeping, terracettes, parallel deep incisions (henceforth: gullies) and stone-banked lobes. The main factors explaining the location of the various landforms are elevation, gradient, aspect, plant cover, soil characteristics, and the topographic index. The statistical analysis clearly separates two types of landforms: (i) shallow landslides, solifluction lobes, and areas of soil creeping, located at relatively low elevations, deep soils and fairly gentle gradients; and (ii) terracettes, gullies and stone-banked lobes, which are generally found at high elevations, on thin soils, north-facing slopes and steep gradients. The declining livestock pressure from the beginning of the 19th century, and particularly from the mid-20th century, explains the progressive re-colonization of the subalpine belt by forest and the reduction in shallow landslides over the last few decades. Most likely, this forest recovery will continue in the near future, with the hydrological, geomorphological and biogeographical consequences still being far from understood. Highlights: Deforestation in the subalpine belt occurred mainly in the Middle Ages to favour the transhumance systems. Deforestation has induced the triggering of a variety of land degradation processes. The spatial distribution of landforms is related to topographic factors and soil depth. Current reduced grazing results in forest expansion and a declining number of shallow landslides.