Burned and devoured : Introduced herbivores, fire and the endemic flora of the high elevation ecosystem on La Palma, Canary Islands - Irl, Severin D. H.; Steinbauer, Manuel; Messinger, Jana; Blume-Werry, Gesche; Palomares-Martínez, Ángel; Beierkuhnlein, Carl; Jentsch, Anke (Arctic, Antarctic, and Alpine Research, 2014)