Teodoro Lasanta

Cortijos López, Melani. Post-abandonment management in Mediterranean mountains: enhancing soil quality, soil organic carbon storage, and Global Change adaptation. Universidad de Zaragoza, febrero 2026. Directora: Estela Nadal Romero.

Land abandonment is a widespread phenomenon in Spain, particularly in Mediterranean mountain areas and semi-arid regions, where it constitutes a key driver of land degradation and desertification. This chapter analyses the environmental consequences of farmland abandonment, with a specific focus on soil erosion and conservation processes. While land abandonment can initiate ecological succession and lead to the recovery of soil quality, this outcome is not guaranteed. In many cases, degradation processes persist or intensify, especially where cultivation had previously exhausted soil fertility, where traditional soil and water conservation practices, such as terracing, have been abandoned, or where recurrent wildfires inhibit vegetation regrowth. In semi-arid environments, low rainfall and high soil erodibility further constrain vegetation recovery, facilitating crust formation, runoff concentration, and gully development. Drawing on evidence from various Spanish regions, the study underscores the importance of site-specific management strategies aimed at mitigating the adverse impacts of abandonment and enhancing ecosystem services. Without appropriate interventions, land abandonment may exacerbate erosion, reduce biodiversity, and increase the risk of irreversible degradation, compromising long-term sustainability in vulnerable landscapes.

Soils provide the substrate for 95% of human food and essential ecosystem services, such as water regulation and biodiversity, while also serving as the most efficient CO₂ sink on the Earth’s surface. However, soil degradation poses a major threat, with significant changes in most of the Earth’s soil attributed to human activities. Common soil hazards in the Anthropocene include: (i) soil compaction, (ii) salinization, (iii) soil contamination, (iv) landslides, (v) decline in soil organic matter, and (vi) soil erosion. Anthropogenic activities greatly impact soil organic carbon (SOC) through land use and land cover changes, agricultural practices, and land management. Indirect effects, such as wildfires, also influence SOC dynamics. Most studies indicate that land use and land cover changes, along with land management, have a greater impact on SOC than the direct effects of climate change. Soil erosion, though a natural process, is significantly exacerbated by anthropogenic factors, leading to a drastic increase in global erosion rates in the Anthropocene. Numerous challenges, opportunities and knowledge gaps have been identified. However, a deeper understanding of both natural and human-induced soil hazards and challenges is necessary. This short review, highlights that a significant amount of work is still needed to fully comprehend the impacts of human activities on soil. Continued research, exploring new questions, is crucial.

El sector ganadero, en especial en su modalidad intensiva, se considera de gran relevancia en el contexto de cambio climático por su contribución a las emisiones de gases de efecto invernadero. Sin embargo, la producción ganadera es necesaria para alimentar a la población y la conservación de ecosistemas y paisajes culturales. Por otro lado, la ganadería extensiva puede ayudar a mitigar el cambio climático a través del pastoreo. En este trabajo se analiza cómo el binomio desbroce de matorrales–pastoreo contribuye a reducir los incendios forestales y a incrementar el almacenamiento de carbono orgánico en el suelo. El trabajo se ha realizado en un sector del Sistema Ibérico Noroccidental (norte de España), un área de media montaña mediterránea muy despoblada. En su paisaje abundan matorrales en distintas fases de sucesión vegetal tras el abandono rural, siendo la ganadería extensiva la principal actividad económica. Desde 1986 el gobierno regional ha desbrozado aproximadamente el 30% de la superficie de matorrales, disminuyendo el material combustible. La superficie quemada ha pasado de un promedio de 1.060 ha/año en el periodo 1968-1986 a 222,6 ha/año entre 1987 y 2023. Se comprueba también que los pastos regenerados tras el desbroce y las repoblaciones forestales gestionadas (aclareos y pastoreo) acumulan más carbono orgánico en el suelo que los matorrales. En estas montañas marginadas hay personas que quieren seguir viviendo de los recursos locales. La ganadería extensiva puede ayudar a fijar población, contribuyendo también a mitigar el cambio climático y a suministrar servicios ecosistémicos a la sociedad.