Journal of Agricultural Meteorology
Online ISSN : 1881-0136
Print ISSN : 0021-8588
ISSN-L : 0021-8588
Full Papers
Estimating vertical distribution of CO2 efflux in a temperate cypress forest
Shinjiro OHKUBONaoto YOKOYAMAYoshiko KOSUGISatoru TAKANASHINaoko MATSUOMakoto TANI
Author information
JOURNAL FREE ACCESS

2009 Volume 65 Issue 4 Pages 339-348

Details
Abstract

We estimated the vertical distribution of CO2 effluxes from trunks, branches, and leaves in a temperate cypress forest by estimating the spatial distribution of biomass. To quantify the distribution of the CO2 source per unit biomass of each organ, we measured the respiration rate of 47 trunk, 26 branch, and 30 leaf samples from one representative tree. To quantify the distribution of biomass per unit height, we measured the positions of all of the branches and leaves, and then collected them to estimate branch volume and leaf area from their dry weight.
Trunk respiration rate per sapwood volume increased with height within the canopy, but no clear difference was apparent below the canopy. The respiration rate per unit volume of lower branches was less than that of higher branches. Small-diameter branches had a higher respiration rate per unit volume than did large-diameter branches. The respiration rate per leaf surface area of leaves higher on the tree was greater than that of lower leaves, as was also the case of leaves farther from the trunk compared with those nearer the trunk. The cumulative trunk, branch, and leaf respiration per ground area at 25°C was estimated to be 1.36, 0.62, and 2.19 μmol m-2 s-1, respectively. CO2 efflux from the trunk per unit height did not differ significantly throughout the tree. The peak CO2 efflux per unit height was greater for leaves than branches. CO2 efflux from the canopy level (>11.5 m) accounted for 75% of cumulative above ground CO2 efflux, excluding soil respiration, and 38% of total ecosystem respiration including soil respiration.

Content from these authors
© 2009 The Society of Agricultural Meteorology of Japan
Previous article Next article
feedback
Top