Vadell, E., de-Miguel, S., & Pemán, J. (2016). Large-scale reforestation and afforestation policy in Spain: A historical review of its underlying ecological, socioeconomic and political dynamics. Land Use Policy, 55, 37-48.

Spain had not more than six million hectares of woodlands in the mid-19th century. Nowadays woodlands cover more than sixteen million hectares. During the last one hundred and fifty years, much effort was devoted to improving forest cover and, as a result, five million hectares were artificially regenerated, which represents ten percent of the whole country area. All this work required large nursery infrastructures, thousands of workers and high public investments. The outcome of these reforestation and afforestation efforts is nowadays obvious throughout the Spanish landscapes, and sometimes has given rise to controversy between supporters and opponents. Nevertheless, the process that led to the vast reforestation of Spain has not been yet studied in depth from a historical perspective. This study aims at reconstructing that historical process, by describing it through several features that help to understand the historical development of the artificial forest regeneration policy in Spain, together with its social, political and economic context. The study period comprises since 1879 to present, with special focus on the recent history, that is, since the mid-20th century. The lessons learnt from this analysis may contribute to improving the design of large-scale reforestation policies as well as their potential impacts in other parts of the world and, in the end, shed light on the debate about the possible solutions to deforestation and forest degradation.

Löf, M., Madsen, P., Metslaid, M., Witzell, J., & Jacobs, D. F. (2019). Restoring forests: regeneration and ecosystem function for the future. New Forests, 50(2), 139-151.

Conventions and policies for biodiversity conservation and climate change mitigation state the need for increased protection, restoration and climate change adaptation of forests. Much degraded land may be targeted for large-scale forest restoration, yet challenges include costs, a shortage of regeneration material and the need for restored forests to serve as a resource for communities. To ensure ecosystem function for the future, forest restoration programs must: (1) learn from the past; (2) integrate ecological knowledge; (3) advance regeneration techniques and systems; (4) overcome biotic and abiotic disturbances and (5) adapt for future forest landscapes. Historical forest conditions, while site-specific, may help to identify the processes that leave long-term legacies in current forests and to understand tree migration biology/population dynamics and their relationship with climate change. Ecological theory around plant–plant interactions has shown the importance of negative (competition) and positive (facilitation) interactions for restoration, which will become more relevant with increasing drought due to climate change. Selective animal browsing influences plant–plant interactions and challenges restoration efforts to establish species-rich forests; an integrated approach is needed to simultaneously manage ungulate populations, landscape carrying capacity and browse-tolerant regeneration. A deeper understanding of limiting factors that affect plant establishment will facilitate nursery and site preparation systems to overcome inherent restoration challenges. Severe anthropogenic disturbances connected to global change have created unprecedented pressure on forests, necessitating novel ecological engineering, genetic conservation of tree species and landscape-level approaches that focus on creating functional ecosystems in a cost-effective manner.

Strassburg, B. B., Iribarrem, A., Beyer, H. L., Cordeiro, C. L., Crouzeilles, R., Jakovac, C. C., … & Visconti, P. (2020). Global priority areas for ecosystem restoration. Nature, 586(7831), 724-729.

Extensive ecosystem restoration is increasingly seen as being central to conserving biodiversity and stabilizing the climate of the Earth. Although ambitious national and global targets have been set, global priority areas that account for spatial variation in benefits and costs have yet to be identified. Here we develop and apply a multicriteria optimization approach that identifies priority areas for restoration across all terrestrial biomes, and estimates their benefits and costs. We find that restoring 15% of converted lands in priority areas could avoid 60% of expected extinctions while sequestering 299 gigatonnes of CO2—30% of the total CO2 increase in the atmosphere since the Industrial Revolution. The inclusion of several biomes is key to achieving multiple benefits. Cost effectiveness can increase up to 13-fold when spatial allocation is optimized using our multicriteria approach, which highlights the importance of spatial planning. Our results confirm the vast potential contributions of restoration to addressing global challenges, while underscoring the necessity of pursuing these goals synergistically.