We tested if subalpine heath vegetation in northern Italy recovered after experimental perturbation of soil 16 nutrient availability (fertilization) and species composition (removal of co-dominant dwarf shrubs). Species 17 cover was assessed non-destructively before the start of the treatments (1995), at the end of the treatments 18 (1999) and 4 years after the treatments ended (2003). Shrub removal had rather modest e ects on heath 19 vegetation, except for mosses which decreased significantly in removal plots. Fertilization decreased the 20 cover of shrubs, mosses, and some graminoids but increased the cover of Festuca rubra. Fertilization 21 converted heath to grassland, but the response of graminoid species was individualistic. Fertilization 22 decreased vascular species richness and evenness, probably through negative effects of shading and litter 23 accumulation on plant growth or recruitment. The vegetation had not recovered completely 4 years after 24 the perturbations had stopped. This suggests that, in contrast to rapid responses to species removal and 25 fertilization, recovery from these perturbations was rather slow, presumably because recovery was affected 26 by long-term biotic interactions and species controls on ecosystem properties.
Recovery of subalpine dwarf shrub heath after neighbour removal and fertilization
BRANCALEONI, Lisa;GERDOL, Renato
2006
Abstract
We tested if subalpine heath vegetation in northern Italy recovered after experimental perturbation of soil 16 nutrient availability (fertilization) and species composition (removal of co-dominant dwarf shrubs). Species 17 cover was assessed non-destructively before the start of the treatments (1995), at the end of the treatments 18 (1999) and 4 years after the treatments ended (2003). Shrub removal had rather modest e ects on heath 19 vegetation, except for mosses which decreased significantly in removal plots. Fertilization decreased the 20 cover of shrubs, mosses, and some graminoids but increased the cover of Festuca rubra. Fertilization 21 converted heath to grassland, but the response of graminoid species was individualistic. Fertilization 22 decreased vascular species richness and evenness, probably through negative effects of shading and litter 23 accumulation on plant growth or recruitment. The vegetation had not recovered completely 4 years after 24 the perturbations had stopped. This suggests that, in contrast to rapid responses to species removal and 25 fertilization, recovery from these perturbations was rather slow, presumably because recovery was affected 26 by long-term biotic interactions and species controls on ecosystem properties.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
