2. Materials and Methods
The experiment took place in May 2014 at the Whole Tree Chamber (WTC)
facility of the Hawkesbury Institute for the Environment (Fig. S1), 60
km northwest of Sydney, Australia. Mean annual temperature at the
facility is 17 °C and mean annual rainfall is 800 mm. We used six
cylindrical and cone-topped whole tree chambers (WTC; 3.25 m diameter,
9.4 m tall) which had climate control units, providing regulation of air
temperature (Tair, °C), relative humidity (RH, %) and
soil water content via irrigation. Aboveground fluxes of water
(H2O) and carbon dioxide (CO2) inside
each chamber were measured automatically using infrared gas analysers
(see Drake et al. 2016). Belowground gas fluxes were excluded
from aboveground water and carbon fluxes by installing an airtight
polyethylene barrier 45 cm above the soil surface. A detailed
description of design, function and measurement routines of the chambers
can be found in Barton et al. (2010). Whole-crown fluxes of
H2O and CO2 inside the chambers were
recorded at 15-minute intervals as explained in Barton et al.(2010) and Drake et al. (2016). Here, we present whole-tree gas
fluxes for daytime periods (07:00-16:00 h).