Abstract
Theory predicts a trade-off between efficiency and safety of water transport in trees (e.g. Tyree and Zimmermann, 2002; Sperry et al., 2008; Meinzer et al., 2010), manifested through changes in tree hydraulic architecture. It is widely observed that average diameters of xylem vessels gradually narrow with decreasing water availability (Carlquist, 2012; Pfautsch et al., 2016). The associated trade-off with narrowing vessel diameter – despite at a higher frequency – is reduced rates of transpiration, lower stomatal conductance and consequently lower foliar uptake of atmospheric CO2 (Santiago et al., 2004; Poorter et al. 2009). Sapwood in such trees is likely to be dense (Chave et al., 2009), arguably due to greater investment in fibre wall thickness that provides increased mechanical strength against the collapse of vessels under high negative pressures (Poorter et al. 2009). Hence, while sapwood of trees in arid environments would consist mostly of narrow vessels, one would expect the hydraulic architecture of trees in mesic environments to feature fewer but wider vessels so as to transport larger quantities of water. This would in turn support high rates of stomatal conductance and uptake of CO2, which fuels rapid growth when synthesizing low-density sapwood (Poorter et al. 2009).
Original language | English |
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Pages (from-to) | 1626-1626 |
Number of pages | 1 |
Journal | Ecology |
Volume | 97 |
Issue number | 6 |
DOIs | |
Publication status | Published - 2016 |
Keywords
- forest ecology
- photosynthesis
- xylem