Lombardi F*, Cocozza C, Lasserre B, Tognetti R, Marchetti M
Contatto: Fabio Lombardi (email@example.com)
Abstract: We investigated the relationship between time-since-death and morphological characteristics of dead downed trees in a forest stand of Nothofagus betuloides in Navarino Island (Chile). In this unmanaged forest, we measured 400 m3 ha-1 of dead wood, representing almost half of the living tree volume. In the investigated site, 18 living trees were selected and increment cores collected to build master ring-width chronologies, and cross-sections were collected from 48 dead downed trees. Samples were assigned to visually discernible decay classes, and their death date dendrochronologically determined. Using cross-dating techniques, dead downed trees cross-dated significantly with standard chronologies, and the year of death was successfully assigned to 75% sampled dead downed trees. However, this study revealed high variability in the transition rate from one class to another, by the standard classification. The inconsistency found in dead downed trees decay rates indicated that existing decay classification schemes are hardly applicable to these forest stands, and that the relationship between qualitatively-assessed decay classes and time-since-death of trees is rather fragile, in either Austral and Mediterranean environments. In addition, the analysis of time-since-death in this old-growth forest suggested how long dead wood remains on the forest floor in cold ecosystems, giving an important contribute to long-term carbon storage.
Citazione: Lombardi F, Cocozza C, Lasserre B, Tognetti R, Marchetti M (2009). Dead wood as sink of carbon: tree rings used to assess deadwood permanence in beech forests in the central Apennines (Molise, Italy) and in Magellan’s beech forests in Navarino Island (Tierra del Fuego, Chile) . 7° Congresso Nazionale SISEF, Isernia – Pesche (IS), 29 Set – 03 Ott 2009, Contributo no. #c7.7.42