Comparative Criteria for Models of the Vascular Transport Systems of Tall Trees

Mencuccini, Maurizio; Hölttä, Teemu; Vilalta, J

doi:10.1007/978-94-007-1242-3_12

Cited by 24 publications

(28 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We used a scaling relation of r p α x 0.25 , i.e., the same as for the xylem. This is an intermediate scaling between the scaling exponent of 0.15 reported by Mencuccini et al (2011), and 1/3 reported by Jensen et al (2011). As distance to leaf apex is scaled from stem diameter, xylem and phloem conduit radius and conductance thus scale with stem/branch diameter, as has been found to be the case for xylem conduits (e.g., Zimmermann, 1983; Olson and Rosell, 2013).…”

Section: Methodssupporting

confidence: 49%

Scaling of xylem and phloem transport capacity and resource usage with tree size

2013

Self Cite

View full text Add to dashboard Cite

Xylem and phloem need to maintain steady transport rates of water and carbohydrates to match the exchange rates of these compounds at the leaves. A major proportion of the carbon and nitrogen assimilated by a tree is allocated to the construction and maintenance of the xylem and phloem long distance transport tissues. This proportion can be expected to increase with increasing tree size due to the growing transport distances between the assimilating tissues, i.e., leaves and fine roots, at the expense of their growth. We formulated whole tree level scaling relations to estimate how xylem and phloem volume, nitrogen content and hydraulic conductance scale with tree size, and how these properties are distributed along a tree height. Xylem and phloem thicknesses and nitrogen contents were measured within varying positions in four tree species from Southern Finland. Phloem volume, nitrogen amount and hydraulic conductance were found to be concentrated toward the branch and stem apices, in contrast to the xylem where these properties were more concentrated toward the tree base. All of the species under study demonstrated very similar trends. Total nitrogen amount allocated to xylem and phloem was predicted to be comparable to the nitrogen amount allocated to the leaves in small and medium size trees, and to increase significantly above the nitrogen content of the leaves in larger trees. Total volume, hydraulic conductance and nitrogen content of the xylem were predicted to increase faster than that of the phloem with increasing tree height in small trees (<~10 m in height). In larger trees, xylem sapwood turnover to heartwood, if present, would maintain phloem conductance at the same level with xylem conductance with further increases in tree height. Further simulations with a previously published xylem-phloem transport model demonstrated that the Münch pressure flow hypothesis could explain phloem transport with increasing tree height even for the tallest trees.

show abstract

Section: Methodssupporting

confidence: 49%

Scaling of xylem and phloem transport capacity and resource usage with tree size

2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…4). Globally, D increases with moisture supply in many contexts (Schulze et al 1998, Miller et al 2001, Turner et al 2008, Diefendorf et al 2010, Kohn 2010, Prentice et al 2010, Mencuccini et al 2011) and decreases with tree height locally (Koch et al 2004, Burgess and Dawson 2007, McDowell et al 2011. Our data suggest that, when relative moisture supply and tree height co-vary along a gradient, the effects of the former on maximum tree height will dominate.…”

Section: Discussionmentioning

confidence: 70%

“…Why does maximum tree height on the Victoria transect track P/E p much more closely than does D? Traditional views of hydraulic limitation include (1) declines in leaf area-specific hydraulic conductance with increasing tree height; (2) declines in w leaf with tree height due to decreased whole-plant hydraulic conductance and increased gravitational potential; and (3) resulting decreases in average stomatal conductance (Ryan and Yoder 1997, Koch et al 2004, Ryan et al 2006, Hinckley et al 2011, Mencuccini et al 2011. Factors that might contribute to a tighter relationship of maximum tree height to P/E p than expected based on hydraulic limitation (and thus D) alone might include (4) increased allocation to leaves vs. roots or stems at a given height with increasing P/E p , or conditions correlated with higher P/E p (e.g., greater soil silt or nitrate content); (5) higher photosynthetic rates per unit leaf mass at higher P/E p or under conditions correlated therewith, independent of the degree of stomatal limitation; (6) higher leaf area-specific conductance at higher P/E p in trees of a given height, reflecting differences in wood density and xylem diameter and length (Thomas 1996b, Thomas and Bazzaz 1999, Zach et al 2010, Fan et al 2012, Gleason et al 2012; (7) variation across species in the rate at which mesophyll photosynthetic capacity declines with decreasing w leaf (Givnish 1986, Tezara et al 2003, Lawlor and Tezara 2009); (8) variation across sites in which the rate at which evaporation from sunlit leaves increases with relative height at the top of the canopy; and (9) greater uncertainties in measuring average D than average height.…”

Section: Discussionmentioning

confidence: 99%

“…Variation in maximum tree height has profound implications for the photosynthesis, growth, crown and bole dimensions, tissue allocation, hydraulic conductance, and population density of individual trees (Givnish 1995, Ryan and Yoder 1997, McDowell et al 2011, Mencuccini et al 2011, Larjavaara 2013, stand biomass, carbon storage, and productivity (Feldpausch et al 2012, Hui et al 2012, Ruiz-Benito et al 2014, leaf area index and transpiration (Roberts et al 2001, Falster et al 2010, net input to ground and surface waters (Bleby et al 2012), and the availability of suitable habitat for certain animals (Wormington et al 2002, Garcı´a-Ferced et al 2011. Over the last three decades, several models have been advanced to account for maximum tree height and its variation with environmental conditions and plant traits.…”

Section: Introduction and Conceptual Frameworkmentioning

confidence: 99%

See 1 more Smart Citation

Determinants of maximum tree height inEucalyptusspecies along a rainfall gradient in Victoria, Australia

Givnish

Wong

Stuart‐Williams

et al. 2014

Ecology

110

View full text Add to dashboard Cite

Abstract. We present a conceptual model linking dry-mass allocational allometry, hydraulic limitation, and vertical stratification of environmental conditions to patterns in vertical tree growth and tree height. Maximum tree height should increase with relative moisture supply and both should drive variation in apparent stomatal limitation. Carbon isotope discrimination (D) should not vary with maximum tree height across a moisture gradient when only hydraulic limitation or allocational allometry limit height, but increase with moisture when both hydraulic limitation and allocational allometry limit maximum tree height. We quantified tree height and D along a gradient in annual precipitation from 300 to 1600 mm from mallee to temperate rain forest in southeastern Australia; Eucalyptus on this gradient span almost the entire range of tree heights found in angiosperms worldwide. Maximum tree height showed a strong, nearly proportional relationship to the ratio of precipitation to pan evaporation. D increased with ln P/E p , suggesting that both hydraulic limitation and allocational allometry set maximum tree height. Coordinated shifts in several plant traits should result in different species having an advantage in vertical growth rate at different points along a rainfall gradient, and in maximum tree height increasing with relative moisture supply, photosynthetic rate, nutrient supply, and xylem diameter.

show abstract

“…Crown architecture also represents the hydraulic pathway Ishii et al 2008) through which water travels to reach transpiring leaves and optimization of water transport is important for maintaining hydraulic functional status, especially in large trees (Mencuccini 2003;Buckley and Roberts 2005;Mencuccini et al 2011). The crown architecture of young trees is hierarchic such that architectural units are sequentially connected in order of decreasing size from the main stem to primary branches to small twigs.…”

Section: How Morphological Changes Might Compensate For Constraints Amentioning

confidence: 99%

How Do Changes in Leaf/Shoot Morphology and Crown Architecture Affect Growth and Physiological Function of Tall Trees?

Ishiga

2011

Tree Physiology

View full text Add to dashboard Cite

With increasing height within the crowns of tall trees, leaves tend to become smaller and thicker and shoots shorter. In tall trees, the vertical variation in leaf/shoot morphology is largely driven by water status. Morphological changes associated with increasing height in the crown present static constraints on photosynthesis, such as decreasing light intercepting area relative to leaf mass and decreasing CO 2 diffusion rate inside the leaf. Despite high light availability, leafarea-based photosynthetic rates at the tops of tall trees tend to be low and this may limit height growth. However, the observed changes in leaf/shoot morphology as well as xylem/leaf anatomy, and crown architecture may compensate for various physiological constraints associated with increasing tree height. Continuous renewal of branches and foliage through epicormic shoot production and the change from hierarchic to polyarchic crown architecture may allow large trees to maintain physiological function and continue to grow.

show abstract

Comparative Criteria for Models of the Vascular Transport Systems of Tall Trees

Cited by 24 publications

References 88 publications

Scaling of xylem and phloem transport capacity and resource usage with tree size

Scaling of xylem and phloem transport capacity and resource usage with tree size

Determinants of maximum tree height inEucalyptusspecies along a rainfall gradient in Victoria, Australia

How Do Changes in Leaf/Shoot Morphology and Crown Architecture Affect Growth and Physiological Function of Tall Trees?

Contact Info

Product

Resources

About