Recovery time (RT) refers to the time (in years) needed for the vegetation component of the ecosystem (dominant tree species present within pixels referenced as forests, or vegetation types for shrubland, grasslands and croplands) to fully recover from a fire event. RT includes both the recovery starting time (RST) and growth rate (GR). RST is the time needed for a species to get the sufficient seed bank to start germination and grow and can be slightly negative for species resprouting from the basal root system to highly negative for species resprouting from apical buds. RST was locally modified with management strategies and climate. GR was derived from standard forest growth models locally modified with climate.
For FirEUrisk, the EU scale RT at 1km resolution, was generated from Corine Land cover identifying forests, shrublands, grasslands, croplands and other areas (non-burnable), potential tree species distribution, and their functional traits related to post-fire regeneration strategy and growth rate. RT was decomposed into RST and GR.
For RST, we collected information on tree species vegetative (resprouting) or seedling emergence (serotiny, seed dispersal) response strategies [1]. We attributed an RST value of -25 years for fire-tolerant species regenerating from trunk buds and -10 years for fire-tolerant species resprouting from belowground material. For species regenerating from the seed bank surviving the fire, we attributed an RST value of 0. Finally, for species without resprouting ability nor post-fire germination from the seed bank, we considered a colonisation delay (0 to 20 years) as the time needed for seeds to be dispersed from neighbouring unaffected ecosystems. Dispersal efficiency was related to seed mass, dispersal strategies and maximum distances [2]. For species employing multiple strategies, we kept the lowest RST between the strategies. RST was locally modified by climate, soil erosion, forest management potentialities, and topography.
For GR, we used each species' yearly growth rate (GR, m.year-1) and maximum tree height (THMAX, m) from forest growth models [3] to derive the Relative Growth Rate RGR (%HMAX.year-1), and derive the time needed for a species to reach its maximum height (RT in years = 1/RGR). GR was locally modified by environmental constraints of Mean Annual Temperature, Mean Annual Precipitation and Soil available water Capacity.
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Vargas, P., Heleno, R., & Costa, J. M. (2023). EuDiS - A comprehensive database of the seed dispersal syndromes of the European flora. Biodiversity Data Journal, 11. https://doi.org/10.3897/BDJ.11.E104079 ↩︎
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