Decoupling of traditional burnings and grazing regimes alters plant diversity and dominant species competition in high-mountain grasslands

Over millennia, the combination of controlled burnings and extensive grazing has maintained mosaic landscapes preserved mountain grasslands in southern Europe. In last century, deep socio-economic changes have led to an abandonment traditional uses, a general decline domestic herbivory misuse burning practices. This study aims quantify how decoupling regimes affects long-term structure, diversity dynamics high-mountain, shrub-encroached grasslands. spring 2012, four treatments (burned-grazed, burned-ungrazed, unburned-grazed unburned-ungrazed) were set up at three sites Special Area Conservation Roncesvalles-Selva de Irati, southwest Pyrenees. During seven years, we monitored floristic composition height native tall-grass Brachypodium rupestre plots each site. burned plots, surveyed resprout dominant shrub Ulex gallii recovering herbaceous vegetation. Plant communities evolved differently grazed ungrazed plots. Extensive grazing, despite being lower than previous decades, plant limited encroachment. The total absence fostered encroachment U. two expansion B. other When cover was >60%, reduced. research highlights competition that occurs between shrubs tall-grasses modulating effect exerted by site-specific features. Understanding local is first step design most appropriate practices help preserve landscape community level high-mountain south