Fire Recurrence and Time Since Last Fire Interact to Determine the Supply of Multiple Ecosystem Services by Mediterranean Forests

Wildfires shape the composition and functioning of Mediterranean ecosystems, but we do not know how these ecosystems respond to both the higher fire recurrence and shorter recovery times expected for future climatic scenarios. We sampled 29 plots with different fire recurrences (from 0 to 4 fires over the past decades) and time since the last fire (up to 35 years; hereafter TSLF) in Southeast Spain, to assess the effect of fire recurrence and TSLF on 25 ecosystem attributes, five related ecosystem services (biodiversity conservation, carbon sequestration, disturbance regulation, food production, and supporting services), plus the synergies and trade-offs between them. High fire recurrence (number of fires) and TSLF interacted to determine ecosystem services but did not affect the synergies and trade-offs between them. Fire recurrence reduced many ecosystem functions and ecosystem multifunctionality. However, this effect dampened, and even became positive, for biodiversity conservation and food production services provided enough (> 20 years) time to recover. The combined effects of fire recurrence and TSLF, however, reduced carbon sequestration and had no overall effects on supporting services. Disturbance regulation, in turn, diminished drastically with the first fire, with no effect of further fires or their interaction with TSLF. Our results show which ecosystem services will suffer more from an increase in fire recurrence, and where restoration and management efforts should focus to maximize the provision of those services more demanded by stakeholders.

This research was funded by the Spanish Society of Terrestrial Ecology and the generosity of A.Traveset (AEET; project REFRESCOME, awarded to S.S.), the HYDROMED project funded by the Spanish Ministry of Science and Innovation (Subprojects BLUEWATER PID2019-111332RB-C21 and INERTIA PID2019-111332RB-C22), and the FIRE-SCENARIO project within the program for emerging research groups funded by the Generalitat Valenciana (GV-2020-160). A.M. is supported by the scholarship of Generalitat Valenciana-European Social Fund (ACIF-2018-194). S.S. and E.P. were supported by the Spanish Government under a Ramón y Cajal contract (RYC-2016-20604). Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.