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Pàgina inicial > Articles > Articles publicats > A synthesis of radial growth patterns preceding tree mortality |
Data: | 2017 |
Resum: | Tree mortality is a key factor influencing forest functions and dynamics, but our understanding of the mechanisms leading to mortality and the associated changes in tree growth rates are still limited. We compiled a new pan-continental tree-ring width database from sites where both dead and living trees were sampled (2970 dead and 4224 living trees from 190 sites, including 36 species), and compared early and recent growth rates between trees that died and those that survived a given mortality event. We observed a decrease in radial growth before death in ca. 84% of the mortality events. The extent and duration of these reductions were highly variable (1-100 years in 96% of events) due to the complex interactions among study species and the source(s) of mortality. Strong and long-lasting declines were found for gymnosperms, shade- and drought-tolerant species, and trees that died from competition. Angiosperms and trees that died due to biotic attacks (especially bark-beetles) typically showed relatively small and short-term growth reductions. Our analysis did not highlight any universal trade-off between early growth and tree longevity within a species, although this result may also reflect high variability in sampling design among sites. The intersite and interspecific variability in growth patterns before mortality provides valuable information on the nature of the mortality process, which is consistent with our understanding of the physiological mechanisms leading to mortality. Abrupt changes in growth immediately before death can be associated with generalized hydraulic failure and/or bark-beetle attack, while long-term decrease in growth may be associated with a gradual decline in hydraulic performance coupled with depletion in carbon reserves. Our results imply that growth-based mortality algorithms may be a powerful tool for predicting gymnosperm mortality induced by chronic stress, but not necessarily so for angiosperms and in case of intense drought or bark-beetle outbreaks. |
Ajuts: | European Commission 659191 European Commission 624473 Ministerio de Economía y Competitividad CGL2015-69186-C2-1-R Ministerio de Economía y Competitividad AGL2014-61175-JIN Ministerio de Economía y Competitividad CGL2013-46808-R Ministerio de Economía y Competitividad CGL2013-48843-C2-2-R Ministerio de Economía y Competitividad CGL2012-32965 Ministerio de Ciencia e Innovación CSD2008-0040 Ministerio de Ciencia e Innovación CGL2007-60120 |
Nota: | Altres ajuts: this study generated from the COST Action STReESS (FP1106) financially supported by the EU Framework Programme for Research and Innovation HORIZON 2020. And the EU Project FEDER 0087 TRANSHABITAT and LIFE12 ENV/FI/000409 |
Drets: | Tots els drets reservats. |
Llengua: | Anglès |
Document: | Article ; recerca ; Versió acceptada per publicar |
Matèria: | Angiosperms ; Death ; Drought ; Growth ; Gymnosperms ; Pathogens ; Ring-width ; Tree mortality |
Publicat a: | Global change biology, Vol. 23 issue 4 (April 2017) , p. 1675-1690, ISSN 1365-2486 |
Post-print. Article 50 p, 2.7 MB |
Post-print. Suplement 20 p, 863.7 KB |