Sample preparation
All samples were collected before 9:00 in the morning. After cutting
samples from a tree in air, large branches were immediately put in a
water-filled bucket and a ca. 20 cm stem segment was cut from the stem
base under water to avoid air entry as much as possible. The length of
the remaining branch samples was between 80 and 160 cm, which was much
longer than the maximum vessel length (MVLstem). Samples
were covered up with a dark plastic bag, transferred to the lab within
10 min, and then rehydrated for more than two hours.