Quick answer: Morro Bay Eucalyptus Groves — The tree that thrives here is the one chosen for this coast: fog, salt, wind and shallow soil are the local constraints, and mature size is the constraint most often ignored. Planting is a matter of putting the right species in a site that can hold it, then keeping the root flare visible and the first summers watered.
Field note. What we see is that the coast is forgiving to the right species and unforgiving to the wrong one: the same tree that looks comfortable four streets in will burn on the windward side of a Cambria lot.
On the other hand, natives are not automatically the answer at every address — a species that belongs in the watershed can still be the wrong size for the garden it is standing in.
The eucalyptus in and around Morro Bay were planted on purpose, by people who expected them to be useful. Blue gum was going to be the timber crop of the new state, and rows of it went in along every rail line and every exposed field on the coast. The timber was a commercial failure — the wood splits and twists as it dries and was never going to replace oak for anything — but the trees did not care, and they grew.
What they were for
Two uses survived the timber failure. The first was shelter: a row of blue gum on the windward edge of a field lifts the airstream, and on this coast that made the difference between a viable dairy and a sandblasted one. The second was shade and a windbreak around a farmstead, which is why the oldest groves sit exactly where a house used to be.
Neither use required the tree to be good wood. It only required it to be fast, salt-tolerant and tall, and on all three counts it delivered.
What they became
A blue gum grove at thirty years is a closed canopy with very little underneath it, because the leaf litter is allelopathic and the shade is dense. At eighty years it is something else: a tall, open stand with big limbs, hollows where limbs have failed, and an insect population that supports a great many birds.
That is how the Morro Bay groves ended up as a heronry. Great blue herons and great egrets nest colonially, and they want tall trees with open flight paths at the height of the nest, near water, and away from ground predators. A mature eucalyptus stand beside an estuary is exactly that. The tree that was planted to be cut for lumber became the reason a colony of herons has a place to nest.
The problem with the stand
Two problems, and they are in tension with the nesting.
The first is fire. Eucalyptus is oily, it drops a continuous layer of fine litter, and it retains dead material in the canopy. A blue gum stand on a slope is one of the fastest-moving fuel beds on this coast, and the same structure that makes good nesting makes a fire ladder from the ground to the crown.
The second is structural. Blue gum grows long, heavy limbs on wood that does not always keep pace, and it drops them without warning — the habit is called summer branch drop and it is a real hazard in a grove people walk through. A limb that fails at forty feet does not need a storm to do it.
What the management actually is
Because the nesting colony is the constraint, the work is scheduled around it: outside the nesting season, which on this coast runs roughly from late winter into summer.
Inside that window, the useful interventions are removal of dead and broken limbs, reduction of the longest lever arms on the trees nearest a path or a structure, and control of the litter layer under the trees that are closest to buildings. What is not useful is thinning the stand for its own sake, because the density is what makes the nesting work.
The removal of a mature eucalyptus is its own problem, which is the subject of what eucalyptus removal actually involves. Where the tree has to come down near a structure, it is a crane-assisted removal with a plan, not a climber with a saw.