Springer Old Growth Forests - Chapter 10 doc

... Wirth Chapter 3 Old Trees and the Meaning of Old Fritz Hans Schweingruber and Christian Wir th3.1 IntroductionWhile the mere presence of old trees does not automatically indicate old- growth ... dendrochronologicaltechnique of cross-dating. As shown in Fig. 3.1, this simple method allows theC. Wirth et al. (eds.), Old Growth Forests, Ecological Studies 207, 35DOI: 10. 1007/978‐3‐540‐ 92706‐8 3,# Springer Verlag ... are generally shorter-lived than trees (Schweingruber 1995) and dwarf-shrubs(see below). The oldest known shrub s grow in Siberia. Hantemirov et al. (2003)found an 840-year -old Juniperus sibirica....

... decrease in net primary productivity in old- growth forests if it occurs is related more to decreasing photosynthesis in old and tall trees (as well as in old- growth forest canopies) than to increasingrespiratory ... shifts compen-sated each other such that relative growth rates were similar across the shade-tolerance gradient, while our results suggest higher growth rates for late-succes-sional shade-tolerant ... in high treesand old- growth forests are still unclear. The widespread hypothesis of hydrauliclimitation will be discusse d in the first part of this chapter. This more source-relatedmechanism...

... for 106 North American forest successions,spanning all major forest types on the continent. The model predicts that formost of these successions, 20 1- to 400-year -old stands (early old- growth) are ... progressing from early- to late-successional conifers, and fromearly-successional hardwoods to late-successional conifers, tended to accumu-late carbon during the early old- growth phase (201 400 ... North American Forests The spectra of carbon stock changes (DCx) across all 106 FCT during the foursuccessional stages (pioneer, transition, early old- growth, and late old- growth) areshown...

... Comparisons with second -growth forests arealso often made to highlight the uniqueness of old- growth forests. 6.2 Structural and Compositional Features of Old- Growth Old- growth forests possess distinct ... environment in old- growth forests, (2) the particular understorey light condi-tions found under such forests, and (3) the unique understorey vegetation assem-blage that can develop in old- growth forests. ... differbetween second -growth and old- growth forests, in boreal (Aubin et al. 2000),northern temperate deciduous (Angers et al. 2005), and tropical (Montgomeryand Chazdon 2001) forests. Old- growth forests...