FERREIRO nicolas Andres
Biological legacies promote succession and soil development on tephra from the Puyehue-Cordon Caulle eruption (2011)
FERREIRO NICOLAS ANDRES; SATTI PATRICIA; MAZZARINO MARIA JULIA
WILEY-BLACKWELL PUBLISHING, INC
Lugar: Londres; Año: 2018 vol. 43 p. 435 - 446
Volcanic deposits have frequently been studied from a successional point of view but the main focus has been on vegetation dynamics, and less frequently on the development of other communities and soil properties. Biological legacies understood as living organisms, seeds, organic debris, and biotically derived patterns in soils and understories have been shown important in succession, and may also influence soil genesis on young volcanic deposits. The volcanic eruption of the Chilean Puyehue?Cordón Caulle complex (Northern Patagonia) in June 2011 deposited tephra in southern Argentina. Sandy tephra up to 30 cm deep was deposited in the De los Siete Lagos road in Nahuel Huapi and Lanín National Parks, where a road under construction had exposed sub-soil lacking vegetation, while adjacent forest supported a canopy of Nothofagus dombeyi with Chusquea culeou in the understory. This situation provided a unique opportunity to study soil formation and succession on nearby young volcanic deposits with different levels of biological legacies, considering several biological communities (microorganisms, invertebrates, plants). Our hypothesis was that 29 months after the eruption the tephra in the forest would have higher organic C, total N, available P and biological activity than the ash deposited on the roadside. We found that nutrient incorporation rates in the forest (0.6 g kg-1 yr-1 C, 0.029 g kg-1 yr-1 N, 1.8 mg kg-1 yr-1 P) were two to six times those in the roadside tephra (0.1 g kg-1 yr-1 C, 0.004 g kg-1 yr-1 N, 0.8 mg kg-1 yr-1 P). In addition, vegetative cover and richness, and invertebrate abundance and richness, as well as tephra respiration, N mineralization and enzymatic activities were highest in the forest. Nevertheless, two and a half years after the eruption most soil variables remained an order of magnitude lower than values expected for temperate forests.