Estructura y Dinámica de Bosques del Tipo Forestal Siempreverde en un Sector de Chiloé Insular

Abstract

A study on structural and dynamic characterization of the forest was carried out in an area of the evergreen forest type located in the neighbourhoods of Chepu, in the Isla Grande de Chiloé. Four stands on undisturbed forests were selected and 54 x 72 m plots were established in each one of them. Data for drawing vertical profiles, for crown classification, stand tables, diameter distribution diagrams, understorey composition and structure and for spatial distribution of the species using the Morisita Index, were collected. Furthermore a soil analysis in each stand was performed with the purpose of studying its morphologic variation and some chemical characteristics related to soil dynamics.
Results show that the sampled stands are floristically and structurally similar and that they grow on two soil conditions. Structure of the forests are characterized by the presence of emergent trees of Eucryphia cordifolia Cav. and numerous specimens of Laurelia philippiana Losser. Amomyrtus luma (Mol.) Legr. et Kauss. is the most characteristics species of these stands due to its abundance and the frequency of "creeping" trees.
The stands structure analysis points out that the differences between sites are derived from a variety of allogenic and autogenetic factors which act upon germination, estalishment and regeneration dynamics of the species. Differences between stands would be determined by different regeneration capacities of E. cordifolia and Drimys winteri R, et Forst. E. cordifolia has the ability to germinate under conditions of moderately wet but well drained soils in open gaps areas of appropriate size (300 to 400 m 2 ) ; conversely, when soil is wet and poorly drained due to development hardpan development, also Amomyrtus meli Kauss. and probably of gleization and E. cordifolia and (Phil.) Legr. et Gevuina avellana Mol. regenerate poorly or not at all, whereas D. winteri germinates and establishes well.