Fire, logging and establishment patterns of second-growth forests in south-central Chile: implications for their management and restoration

Abstract

© 2015, Pontificia Universidad Catolica de Chile, Facultad de Agronomia e Ingenieria Forestal. All rights reserved. Second-growth forests represent the greatest potential resource for forest management and large-scale ecological restoration in many regions. In south-central Chile, second-growth forests include those dominated by Nothofagus obliqua, N. dombeyi, Drimys winteri, and a mixture of evergreen species, especially hardwoods. This article examines the influence of fire and logging on the establishment patterns and development of second-growth forests in south-central Chile. We characterize the size structure and composition of these four types of forests with sampling plots. The identification of the type of disturbance and its date of occurrence was determined from evidence such as fire scars and even-aged pulses of tree establishment. The size, structure and species composition of these forests indicate an intermediate state of development with an average density and basal area ranging from 1294 to 5038 trees ha-1and from 59 to 85 m2ha-1, respectively. Logging and/or devastating fires that occurred in the early decades of the 1900s promoted the relatively rapid establishment and growth of pioneer species (Nothofagus obliqua, N. dombeyi, D. winteri). In the Mixed Evergreen second-growth forests, mid-shade or shade tolerant species (e.g., Gevuina avellana, Eucryphia cordifolia, Amomyrtus luma, and A. meli) became established mostly through vegetative sprouting. Fires and logging have been pervasive factors in determining the structural and compositional uniformity of the native forests of south-central Chile. Ecological restoration at a landscape level, either by ecological processes (i.e., a reduction in fire frequency) and/or the structure and composition of second-growth forests, provide a relevant approach to accelerating the generation of attributes of old-growth forests, therefore meeting manifold societal demands for forest goods and services.