The Emperor Tree was dead.
At least, that was the presumption.
No Larkinson was willing to say for certain whether the tree was dead. Not when the bottom half of its massive trunk and its astronomically large root system still remained undamaged.
However, when Saint Isobel and the Promethea finally managed to burn the entirety of the tree heart that rested in the very center of the calamity plant, its remaining 'body' instantly lost activity.
Technically, the pieces of wood still remained 'alive', for a given definition of the word.
They just lost any visible sign of conscious direction. If the tree heart functioned as the Emperor Tree's brain, then the remainder of the massive tree had turned into the equivalent of the body of a brain dead patient.
The lack of direction from a central consciousness that was powerful enough to command such an enormous organism caused the enormous tree mass to become lost.