Volcanic eruptions provide a unique opportunity to track changes in ecosystems longitudinally as systems recover. We examine community patterns in Patagonian Chile, in forests directly impacted by destructive tephra-fall in the 2015 eruption of Calbuco Volcano. We examine changes in soil organic matter, soil C and N, and vegetative community over four years of regrowth.
Results/Conclusions
Over-all, ecosystem recovery was dramatic. Percent vegation cover increased by 6-fold (5-35%) and species richness tripled (10-30 species) over five years of monitoring. Soil OM and C initially declined, and then has increased through time, approaching 1/3 of pre-eruption values within 5 years. Among vegetation types, recovery is dependent on elevation and amount of overstory decline in the eruption. At low elevation, where tree mortality was lower, recovery over five years has been driven by graminoids (a bamboo species) and tree regrowth. At high elevation, recovery has been driven by shrub species (e.g., Fuchsia ) and less-so by tree regrowth. An intermediate site demonstrated regrowth driven by both trees and shrub species. Ordination and multivariate analyses suggest that the vegetation shifts initiated by the volcanic eruption will continue to influence these sites through time. Recovering vegetation is has continued along a distinct community trajectory in each of three elevations studied. Recovery following volcanic disturbance is highly dependent on abiotic conditions and the life-history strategies of dominant plants existing at the site prior to the disturbance. Because species distribution is somewhat predictable by elevation, it is also possible that resilience to volcanic disturbance may also be predictable by elevation.