Chapter 16 Old-Growth Temperate Rainforests of South America: Conservation, Plant–Animal Interactions, and Baseline Biogeochemical Processes Defining old-growth forests (Chap. 2 by Wirth et al., this volume) must consider both technical and cultural issues. For instance, the term ‘old-growth forest’ was entirely absent from the most recent survey | Chapter 16 Old-Growth Temperate Rainforests of South America Conservation Plant-Animal Interactions and Baseline Biogeochemical Processes Juan J. Armesto Cecilia Smith-Ramirez Martin R. Carmona Juan L. Celis-Diez Ivan A. Diaz Aurora Gaxiola Alvaro G. Gutierrez Mariela C. Nunez-Avila Cecilia A. Perez and Ricardo Rozzi Introduction Defining old-growth forests Chap. 2 by Wirth et al. this volume must consider both technical and cultural issues. For instance the term old-growth forest was entirely absent from the most recent survey of Chilean vegetation conducted by the National Forest Service CONAF-CONAMA-BIRF 1999 where the forestry-related term adult synonym of tall 15 m height forest was used instead to indicate a harvestable unit of land. Moreover the deriding term over-mature is sometimes used to refer to old-growth stands with a predominance of large non-harvestable trees Chap. 2 by Wirth et al. this volume . This bias towards a tree-centred commercial view of forests suggests that culturally we remain unaware of the ecological differences among successional forest stages and of the specific attributes of old-growth forests. Greater public appreciation of the ecological social and economic values of old-growth forests will depend on our ability to communicate scientific understanding of these diminishing ecosystems. Based on current knowledge of temperate forests in southwestern South America . Donoso 1993 Armesto et al. 1996a Veblen et al. 1996 Neira et al. 2002 we propose here a definition of old-growth forest that combines both structural and compositional based on species and functional groups properties of forest stands. The old-growth condition is usually restricted to ecosystems that have not been subjected to recurrent and massive human impact Chap. 2 by Wirth et al. this volume . Considering the entire range of human impacts from changes in the concentration of elements in the atmosphere to the extraction of individual trees it is however .
