Dr. Julien's Hidden Workshop is located here, hidden within one of the many birch trees. The Juggernaut patrolled the forest, protecting the workshop from intruders and the hostile Treehorn population until Zane destroyed it. It is also where Zane and the Falcon were created.
During the Serpentine Wars, a pivotal battle took place between the elemental alliance and the Anacondrai in Birchwood Forest with the snakes claiming victory due to the betrayal of the Elemental Master of Earth.
Snake Jaguar (Flashback)
When the Falcon appeared before the Ninja for the third time, it led them on a chase through the land of Ninjago. Only Kai and Zane had the stamina to follow the bird to Birchwood Forest, and Kai had to stop shortly after arriving to catch his breath. Zane continued to follow the Falcon until it broke down and he was attacked by the Juggernaut. After destroying the guardian robot, Zane found the Hidden Workshop, where he learned of his origins.
The other three Ninja eventually caught up with their comrade, only to be attacked by Treehorns. After coming to terms with his true nature, Zane emerged to fend off the beasts and their queen, unlocking his True Potential in the process.
The Birchwood Forest played host to the second leg of the annual Ninjaball Run. Lou and the Royal Blacksmiths crashed shortly after entering the forest, when their truck hit a fallen tree and spun out into a snowbank. The Ninja managed to close the distance on their competitors when Lloyd flew over the canopy and spotted a shortcut for the Ultra Sonic Raider. Unfortunately for the Green Ninja, he was subsequently taken out of the race when the Ultra Dragon was pulled out of the air by Kruncha and Nuckal's Skull Truck - however, the dragon's weight caused the Skulkin to crash in turn.
Jay pursued one of Chen's Noodle Trucks to the forest where he managed to corner it, only to discover it was empty.
From the forest, Jay attempted to use the truck's radio to contact Nya, but Chen blocked the signal.
On the Day of the Departed, Zane returned to Birchwood Forest to remember his father, Dr. Julien. While there, he encountered a reincarnated Cryptor accompanied by several Nindroids and fought with them amidst the forest.