Land-use policies overcome fire suppression effects on functional diversity in a fire-prone, abandoned mountain area

Abstract

ContextClimate and land-use changes are contributing to impacts on global ecosystems functioning. These effects are particularly severe in areas undergoing land abandonment and extreme wildfire events, such as the Mediterranean regions of Iberian Peninsula.ObjectivesPrevious studies have evaluated the impacts of land management on fire mitigation and biodiversity, but how such strategies influence functional diversity remains unexplored. This study investigates if alternative land-fire management strategies affect functional diversity.MethodsManagement scenarios were modelled for 2050 on the Transboundary Biosphere Reserve Gerês-Xurés (Portugal-Spain). The land-use scenarios simulated processes of land abandonment (“business-as-usual” – BAU) and the implementation of EU rural policies (“High Nature Value farmlands” - HNV), and were combined with three fire suppression levels. Species distribution models (102 vertebrates) were projected to each scenario and functional diversity indices were consequently calculated.ResultsThe highest functional richness was predicted for BAU scenarios, probably representing the benefits to unique species that deliver singular functions. The HNV scenarios provided the highest functional divergence, probably indicating a high niche differentiation and low resource competition amongst agricultural communities. HNV was the most beneficial scenario for ecosystem functioning, while fire suppression did not affect functional diversity.ConclusionsDespite the proneness to burn of our study area and the effects of firefighting on its fire regime, land-use policies are expected to overcome fire suppression effects on functional diversity. These findings suggest that different facets of functional diversity will be unevenly influenced by fire-landscape dynamics driven by the land-use policies to be implemented in the upcoming decades.