A tree harvester 10 comprises a chassis, at least one ground engaging mechanism configured to propel the chassis over the ground, a harvesting head 25 including a saw configured to cut trees, a plurality of hydraulic units including a hydraulic motor to power the saw and a hydraulic control system including a first hydraulic pump providing pressurized hydraulic fluid, a plurality of valves controlling the supply of hydraulic fluids from the first hydraulic pump to the plurality of hydraulic units, a load sense system that detects the load pressure requirements of the plurality of hydraulic units and provides instruction to the first hydraulic pump to produce pressure sufficient to satisfy the requirements of a highest of the load pressure requirements of the plurality of hydraulic units, a second hydraulic pump providing hydraulic fluid to the harvesting head 25 and at least one pressure sensor detecting the load pressure required by the harvesting head 25 and communicating the load pressure to the load sense system to control operation of the first hydraulic pump and to the second hydraulic pump to control operation of the second hydraulic pump.
