Variation in sap flux density and its effect on stand transpiration estimates of Korean pine stands

• DOI: 10.1007/s10310-014-0463-0
• Publication Date: 2014-09-11T05:49:16Z
• Authors: Minkyu Moon; Taekyu Kim; Juhan Park; Sungsik Cho; Daun Ryu; Hyun Seok Kim
• Keywords: Variation (astronomy); Coefficient of variation; Platycladus; Pith; Tree (set theory); Pinus koraiensis

AbstractAccurate estimates of stand transpiration (E) require the consideration three types variation in sap flux density (JS): radial, azimuthal, and tree-to-tree variation. In this study, JS 50-year-old Korean pine (Pinus koraiensis) trees its effect on E was evaluated using Granier-type heat dissipation sensors. The value decreased exponentially with radial depth from cambium to pith, coefficient (CV) for 124.3 %. Regarding azimuthal variation, differed significantly among aspects average CV 23.6 34.0 %, daily increased increasing vapor pressure deficit (D). error caused by ignoring largest (109.2 %), followed those variations (24.3 12.6 respectively). While contribution minimal comparison other variations, significant, usage north aspect measurement did not generate substantial (0.6 %). Our results suggest that particularly species- site-specific must be considered when accurately calculating estimates.Keywords: Azimuthal variationRadial variationSap fluxStand transpirationTree-to-tree AcknowledgmentsThe primary funding study provided Korea Forest Service (project number: S111214L020100) Meteorological Administration 1401-HH-001-02D02-2014). We are also thankful support Mt. Teahwa Seoul National University staff.