Interesting thread. Birch would be the fiirst coloniser (I believe)
Dec 24- Jan 20
LORE:    The Birch is self-propagating (as is the year). It is the earliest Tree to put out leaves (with the exception of the Elder). Its bark is "snow white". Birch rods drive out "evil", and The Old Year. Birch was used for cradle wood.

http://feraferia.org/joomla/index.php?option=com_content&view=article&id=102:tree-alphabet-calendar&catid=48:ancient-ideas&Itemi

is the Order of Battle in the Cad Goddeu:
Birch Rowan Alder Willow Ash Whitethorn Oak Holly Hazel Wild-apple
Vine Ivy J Reed Blackthorn Elder[BroomPalm Fir JGorse Heath Poplar Yew Mistletoe [Furze)Privet Woodbine Pine

Could be a total wild goose chase but the White Goddess is an interesting read.