The connection and importance of the blue oaks with the ocean
Two main forces the blue oaks evolved with are missing: Summer fog and the August Monsoons. The inland days would get hotter and hotter and in response a thick fog would roll in off the ocean and blanket coastal California. The Central Valley would have days so hot you could fry an egg on a rock then the nights would cool and the response would be tule fog so thick you couldn’t see your hand stretched out in front of you. California evolved with thick summer night fogs which the oaks drank in through their canopies, hydrating the lace lichen which would immediately start producing vitamins and softly dripping them into the ground below the oaks, then when the trees used all they could, the excess water would be expelled through their roots sending healthy streams and creeks full of minerals and ancient soil microbes into the rivers which helped to feed the food chain along the way to feeding the oceans and then came back again as the fog kept the cycle going.
When there was no fog there were the monsoons. Many a day past when we watched the days creep above the 100 mark and then the thunderheads would roll in with clashing symbols and lightening unzipping the clouds to send down short-lived torrential rains that would immediately plummet the temperatures down to the 70s. There would be the cycle again; oak canopies soaking in the rain to process it water everything around them and then send the rest, full of nutrients, back to the ocean.
It takes moisture on the ground to foster fog, that is the extreme importance of native understory to blue oaks. They and their entire ecosystem cannot survive without the understory.
Understory:
cool and moist in heat of summer
gives all animals (includes bugs, birds, and pollinators) a place to feed, hydrate, rest, etc.
a place for oak seedlings to germinate and grow, well fed and safe, into saplings
native plants reach down into the earth for moisture, finding it in and around rocks in the ground, etc.
Invasives such as the annual grasses, create a thatch at the top of the soil and greedily hold all the water they can for themselves, not letting it down to the aquifers.