GIORDANO Carla Valeria
Gregarious bamboo flowering opens a window of opportunity for regeneration in a temperate forest of Patagonia
GIORDANO, C.V.; SÁNCHEZ R. A.; AUSTIN A. T.
WILEY-BLACKWELL PUBLISHING, INC
Año: 2009 vol. 181 p. 880 - 880
1. Rare gregarious flowering of understorey bamboo species occurs in temperate and subtropical forests around the world, but the ecological consequences of this phenomenon for forest regeneration are not well understood. 2. We conducted field experiments in an old-growth temperate forest of Patagonia, Argentina after a massive bamboo flowering event, to examine if light quality and other changes in microhabitats could affect seed germination and growth of overstorey species. 3. Germination of southern beech (Nothofagus obliqua) was significantly positively correlated with red:far red (R:FR) ratios in a range of microhabitats generated by the death of the understorey bamboo. Experimental modification of understorey R:FR ratios to mimic alternative light environments reversed this germination response in plots with senescent understorey, but not in plots with live bamboo. Laboratory incubations demonstrated a significant interaction between R:FR ratios and thermal amplitude in promoting seed germination. Microhabitats also significantly affected the growth response of emerged seedlings. 4. Microenvironmental changes generated by this flowering event appear to have opened a window of opportunity for germination and growth of overstorey species. We demonstrate that natural gradients in light quality associated with this ecological phenomenon are a major component affecting forest regeneration in this ecosystem.