Effects of volcanic ash deposition on the early recovery of gap vegetation in Northwestern Patagonian steppes

GHERMANDI L.; GONZALEZ S.; FRANZESE J.; ODDI F.

JOURNAL OF ARID ENVIRONMENTS

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2015 vol. 122 p. 154 - 160

0140-1963

Volcanic eruptions can cause changes in plantcommunities through the effects of ash fall. We studied the effect of ashdeposition on vegetation recovery in inter-plant patches (gaps) following theeruption of the Puyehue-Cordón Caulle volcano (June 2011) in the NorthwesternPatagonian steppe of Argentina. We estimated the aboveground vegetation coverand the seed bank abundance (April 2012) in gaps with and without ash (November2011 and December 2012). We compared the sampled data with studies performed inthe area before the eruption. Total plant cover was greater in gaps with ashcompared to gaps without ash. Ash deposition suppressed cover of therophyteexotic species, but augmented total cover due to the increase of geophytecover. Pre- and post-eruption soil seed bank was dominated by therophytes,mostly exotic species. However, ash deposition decreased the abundance of thetotal seed bank, including therophyte species. The position of buds and plantsize in relation to ash layer thickness were important in determining plant recovery.  Our results indicate that ash derived fromvolcanic activity can change species abundance and composition of steppe gapsthat are important for the regeneration of matrix species.