Determination of tree stem water content
To examine the volume and use of stored plant water, we determined the relative wood moisture content (WMC). For this, two horizontal wooden cores (1” x 0.5” cylinder) were extracted at breast height from 16 trees with a perforating puncher at the opposite sides of the trunk (four cores per species/plot) at the end of each of five ecohydrological periods (depletion: February 2013 and April 2014; recovery: May 2013; wet: October 2013 and 2014) (n=64). In this case, the number of samples was small to reduce the damage of sap conduction through the trunk. Relative wood moisture content (WMC) was calculated by using the fresh weight (Wfresh) and dry weight (Wdry) (48 hours at 70ºC) of each sample:
WMC = (Wfresh – Wdry) / Wdry x 100%