Hydraulic properties and embolism in small-diameter roots of five temperate broad-leaved tree species with contrasting drought tolerance

作者：Koecher Paul; Horna Viviana; Beckmeyer Ingo; Leuschner Christoph

来源：Annals of Forest Science, 2012, 69(6): 693-703.

DOI：10.1007/s13595-012-0189-0

• Acer pseudoplatanus
• Carpinus betulus
• Coarse roots
• Drought tolerance
• Fagus sylvatica
• Fraxinus excelsior
• Root hydraulic conductivity
• Root embolism
• Tilia cordata
• Vessel diameter

It has been estimated that about half of a plant%26apos;s total hydraulic resistance is located belowground, but it is not well known how temperate tree species differ in root hydraulic properties and how these traits vary with the species%26apos; drought tolerance. %26lt;br%26gt;We examined root anatomical and hydraulic traits in five broad-leaved tree species with different drought tolerance, analyzed the relation between root anatomy and hydraulic conductivity and root embolism, and investigated the relation of these traits to the species%26apos; drought tolerance. %26lt;br%26gt;In small-diameter roots (2-6 mm), we measured vessel diameters and vessel density, specific hydraulic conductivity, and the percental loss of conductivity (%26quot;native%26quot; embolism) during summer in a mixed forest. %26lt;br%26gt;Specific conductivity was positively related to vessel diameter but not to vessel density. Drought-tolerant Fraxinus showed the smallest mean vessel diameters and drought-sensitive Fagus the largest. Specific conductivity was highly variable among different similar-sized roots of the same species with a few roots apparently functioning as %26quot;high-conductivity roots%26quot;. %26lt;br%26gt;The results show that coexisting tree species can differ largely in root hydraulic traits with more drought-sensitive trees apparently having larger mean vessel diameters in their roots than tolerant species. However, this difference was not related to the observed root conductivity losses due to embolism.

• 出版日期2012-9