Look around in a Giant Tree Taiga or plant a giant spruce by bonemealing 4 spruce saplings together and you may get a very short and out of proportion giant spruce tree. This does not apply to giant spruce trees from Giant Spruce Taiga.
An unknown type of giant spruce tree?
Giant Spruce grow uncorrectly
Leaves of acacia trees generate differently than before
Trees now require much more free space around them to grow
Savanna biomes have a lot more grass than before