Transpiration from a Cryptomeria japonica plantation, part 1: Aerodynamic control of transpiration

Hikaru Komatsu, Yihuei Kang, Tomonori Kume, Natsuko Yoshifuji, Norifumi Hotta

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)

Abstract

To our knowledge, no one has examined the canopy conductance of a Cryptomeria japonica plantation, although such forests are very common in Japan. We plan to examine the canopy conductance of a Cryptomeria japonica plantation (canopy height 8 m) based on 1-year sap-flow data using the simplified Penman-Monteith equation. This study examines the effect of the aerodynamic control of transpiration before calculating canopy conductance using the simplified Penman-Monteith equation, because the equation assumes that the effect of aerodynamic control is negligible. To examine the effect of aerodynamic control, we examined the dependency of the relationship between the vapour pressure deficit (VPD) and transpiration on wind speed, when solar radiation, air temperature, and soil water content do not limit transpiration greatly. The relationship between VPD and the heat pulse velocity measured 11 m above the ground was dependent on wind speed only when the wind speed was <0·7 m s-1. This suggests that the effect of aerodynamic control was negligible when the wind speed was ≥0·7 m s-1, but that the effect was not negligible when the wind speed was <0.7 m s-1. Therefore, we should use data from when the wind speed was ≥0·7 m s-1 for calculating canopy conductance Gc, based on the simplified Penman-Monteith equation. Although this criterion is site specific, the methods used to develop it are applicable to other sites.

Original languageEnglish
Pages (from-to)1309-1320
Number of pages12
JournalHydrological Processes
Volume20
Issue number6
DOIs
Publication statusPublished - Apr 15 2006
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Water Science and Technology

Fingerprint Dive into the research topics of 'Transpiration from a Cryptomeria japonica plantation, part 1: Aerodynamic control of transpiration'. Together they form a unique fingerprint.

Cite this