Investigador responsable: Javier A. Simonetti
Coinvestigadores: Ramiro O. Bustamante & Audrey A. Grez
Período: Marzo 2001 – Marzo 2005
Financiamiento: Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT 101852
Forest fragmentation is an increasing landscape modification, wich triggers widespread and multiple abiotic and biotic changes in the remaining forest fragments compared to the original continuous forest. Increasing evidence suggests that fragments are unlikely to preserve intact plant assemblages but tree regeneration processes have receives little attention, particularly the factors that might alter seedling establishment and mortality. Such will the focus of our project. Seed availability, seed germination and seedling herbivory could be modified by forest fragmentation, but these effects can be mediated by seed size. Large seeded-species should face a more favorable enviroinment in forest fragments compared to small-sized species. Large seeds germinates more often than small ones when facing stressing microclimatic conditions as those exhibited by forest fragments. Furthermore, seedlings emerging from arge seeds growth faster and cope better with herbivory than seedlings fron small-sized species. Seedlings from large seeds should growth faster and succefully establish in fragments, tending to dominate the future canopy. Therefore, fragmentation could alter the structure and dynamics of fragmented forests modifying recruitment rates of tree species. Here we will unravel the role of seed availability, seed germination and herbivory upon the recruitment of tree species that differ in seed size in fragmented forests of central Chile. First, we will assess seedling recruitment patterns in fragments and continuous forests as relates to seed availability. Second, we will experimentally test whether large seeds (Nothofagus glauca and Cryptocarya alba) germinates and establish as seedlings in higher proportion than small seeds (Nothofagus obliqua and Aristotelia chilensis) in forest fragments. Third, we will experimentally tests whether seedlings of large-seeded species (Nothofagus glauca and Cryptocarya alba) survive herbivory better than seedlings of small-seeded species (Nothofagus obliqua and Aristotelia chilensis). Furthermore, we will assess the abiotic conditions in forest fragments (water availability, soil temperature and humidity) as well as the abundance of insects, the most important seedling herbivores. By monitoring seedling establishment related to seed availability (a pattern) and analyzing germination rate and herbivory and seedling establishment (processes) we aim to understand forest recruitment and its final effect upon forest biodiversity.