%0 Journal Article
%T Patterns of tree seedling mortality in a temperate-mediterranean transition zone forest in Chile Patrones en la mortalidad de pl芍ntulas de especies arb車reas de un bosque de la transici車n templado-mediterr芍nea de Chile
%A TERESA PARADA
%A CHRISTOPHER H. LUSK
%J Gayana. Botanica
%D 2011
%I Universidad de Concepci車n
%X Seedling mortality in forests is the net result of an array of processes that vary spatially and temporally. We quantified emergence and mortality of seedlings at monthly intervals for two years, in a forest situated in the transition zone between the Mediterranean and temperate regions of Chile. We aimed to determine if survival of species responded differentially to seasonal water availability, to the spatial variation in light availability and to seedling density. The commonest species in the seedling bank were the Mediterranean-climate species Cryptocarya alba (61%) and the temperate-climate species Aextoxicon punctatum (29%). 279 of the 504 new seedlings that emerged during the two-year study died during the same period, corresponding to 55,4% mortality. Four of the less common species (Persea lingue, Peumus boldus, Nothofagus obliqua and Luma apiculata) suffered 100 % mortality of new recruits. Mortality of A. punctatum showed a marked seasonal pattern, with high mortality during the dry summer months. In contrast, mortality of the Mediterranean-climate species C. alba was more evenly distributed throughout the year. Multiple regressions showed that light availability had no significant effect on mortality of A. punctatum or C. alba. The same analysis revealed that survival of A. punctatum was negatively affected by conspecific seedling density, but this density-dependent effect was not found for C. alba. Heterospecific density-dependent effects were not found, i.e. mortality of neither species was affected by local density of seedlings of other species. This study shows that spatial and temporal variation in critical factors shapes interspecific variation in seedling mortality in this forest. La mortalidad de las pl芍ntulas es el resultado de una gama de procesos y agentes que pueden variar espacial y temporalmente en los ecosistemas forestales. En este estudio cuantificamos la emergencia y mortalidad de pl芍ntulas mes a mes, por un per赤odo de dos a os en un bosque situado en la zona de transici車n entre la regi車n mediterr芍nea y templada de Chile. Pretendimos dilucidar si las especies sobreviven en forma diferencial a la disminuci車n estacional en la disponibilidad de agua, a la variaci車n espacial en la disponibilidad de luz y a la densidad local de pl芍ntulas. Las especies m芍s abundantes en el banco de pl芍ntulas son la escler車fila Cryptocarya alba (61%) y la especie templada Aextoxicon punctatum (29%). Del total de 504 pl芍ntulas emergidas durante el estudio, murieron 279, lo que corresponde a un 55,4 %. Cuatro de las especies menos abundantes (Persea
%K Aextoxicon punctatum
%K Cryptocarya alba
%K mortalidad densodependiente
%K tolerancia a la sequ赤a
%K tolerancia a la sombra
%K Aextoxicon punctatum
%K Cryptocarya alba
%K density-dependent mortality
%K drought tolerance
%K shade tolerance
%U http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432011000200015