Mosaic landscape restoration after wildfire under Mediterranean-continental conditions

Wildfire is a natural disturbance in the Iberian Range, often caused by lightning. After the 7,600 ha fire in the Cuencas Mineras de Teruel region in 2009, a restoration project is being carried out on 1,234 ha with the aim of developing a forest adapted to challenges as a) new climate scenario; b) future fires; c) wild ungulate expansion/livestock management. Four ecosystem services have been prioritized: water supply, carbon storage, livestock feeding, and biodiversity.

Forest recovery has been promoted by means of plantations as well as spontaneous revegetation (26% and 11,5% respectively of the pre-fire forest surface). Plantation has been made in scattered stands in order to create fire discontinuity. Trees density has been lowered (750-1.100 trees/ha) to reduce fuel in the forest and increase water availability per tree. Resprouting and seeding species have been introduced. Pinus halepensis has been planted above 1,000 m of altitude because conditions are getting drier and warmer. Since 2014 71,75 ha have been planted with a survival rate of around 63,5%. The least successful species has been Pinus sylvestris (50% on average) with the lowest records in sunny exposures and convex landforms due to the new climatic scenario. The sustainable stocking density has been estimated at 700 ewes to promote livestock activity. In order to enhance the sheep flock activity a livestock pen has been built that allows the grazing season to be extended over time. We assume that in planted stands, rainwater will be consumed by the vegetation (evapotranspiration: green water). In non-planted areas, livestock activity is encouraged, thus acting as firebreaks and as producers of blue water, since part of the rainwater will recharge aquifers and watercourses.

Biodiversity results favored by spontaneous revegetation as well as by the protection of the Natura 2000 habitat 6210 “Semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometalia)”, which has not been planted. In practice, a mosaic landscape has been constructed.

The water supply (blue/green water ratio) has been estimated by applying Zhang's hydrological model.  Barandica and Berzosa model was used for carbon storage estimation. Four scenarios have been considered: a) traditional land uses before rural depopulation (the year 1956); b) pre-fire landscape (the year 2009); c) post-fire landscape (the year 2012); d) restored forest (the year 2050). Results show an increase of about 4,5% in water supply and a decrease of about 40% in carbon storage when comparing the pre-fire scenario with the restored forest. An integrative approach including the management of water, carbon, livestock, and biodiversity is necessary in order to develop mosaic landscapes resilient to the main disturbances in the Mediterranean-continental environments.