Indicating Past Fires

I’m chopping firewood and remembering all the old native Pacific madron trees (Arbutus menziesii) that used to grace pockets of the forest around my house. The trees rarely occur in pure stands. Some had trunks three feet or more in diameter at breast height (DBH). (I don't know who's breast.) Over the past 22 years all but a handful have died a natural death and were resurrected as firewood.

At only 80-100 years, these are so short-lived trees compared to the mixed coastal oak (Quercus agrifolia), Douglas-fir (Pseudotsuga menziesii), tanoak (Lithocarpus densiflorus), the California coast redwood (Sequoia semperviren) – with a DBH of 8-25 feet - and California bay trees (Umbellularia californica) in “my” forest. This is because the madrone, while drought resistant, is a colonizer of fire-scorched earth. They are among some of the first trees to sprout after a fire. It is said the seeds need fire to germinate. (However, most germination in nurseries is done by freezing the seed before planting in flats or tree tubes.) These trees at first grow more rapidly than the Douglas fir trees associated with a more mature forest. They help to stabilize the soil. Eventually the Douglas fir trees grow above the madrones and shade them to death.

To maintain madrone in a mixed Douglas fir, oak, and redwood forest, the tree needs fire. Not a firestorm in the tops of mature trees, but frequent fires about every five to 50 years. Pacific madrone depends, on these periodic fires to eliminate or greatly reduce the beginning of a Douglas fir overstory.

However, the forest here hasn’t burned in over 100 years. (A 1/2-acre fire last week a mere two miles from my house was quickly extinguished. What a close call and a relief!) The amount of “kindling” (dead trees and shrubs as well as the invasion of foreigners along parts of the forest’s edge like Scotch broom (Cytisus scoparius), which act like little balls of standing gasoline because they burn so easily and hot) on the ground is tremendous. When the next fire comes the burning grasses or Scotch broom will leap up the trunks of the trees to form a crown, or canopy, firestorm. Nothing, except the noble redwoods, will be left. Including my house.

This photo is of one of the few Pacific madrone trees left on the property as it snakes toward sunlight from beneath the maturing Douglas fir trees.

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Falling for Fall...well, sort of

The heat waves of the past month have produced a semi-deciduous forest. The leaves pictured here belong to the native bay tree (Umbellularia californica) - also known as 'pepperwood', 'California laurel' and, in Oregon, 'Oregon myrtle', or simply myrtle. This is NOT the leaf found in the store that is sold as a bay leaf (Laurus nobilis). This is yet another late summer drought strategy to reduce the surface area transpiring ever-dimensioning moisture supplies. The lane that leads to my house is littered after a strong wind with needles of the redwoods and the leaves of bay trees. But many needles and leaves remain in this evergreen forest.

We do have leaf fall in my neck of the woods. It’s just a few: the native horse chestnut (Aesculus californica), thimbleberry (Rubus parviflorus), wild currants (Ribes spp.), spice bush (Calycanthus occidentalis), and maple (Acer macrophyllum). The colors appear washed out or muddy if there is too much heat. A cool, late summer will make the maples glow yellow against a dark-green evergreen forest. The horse chestnut loses all its shriveled-up brown leaves a month or two before the chance of rain as a drought-protective “strategy”. The only bright and clear colors come from the poison oak (Toxicodendron diversilobum) snaking up a Douglas fir or Coast oak, with the most vibrant reds and oranges of any other native plant around my house.

Back in the ‘70s I was experimenting with friends on wild, native, and lesser-known edibles. We skinned the bay fruit, slit the seed’s skin, extracted the nut and proceeded to cook it in a pan until almost a coffee substitute. Tasted “interesting”. It seemed to be only a last-ditch survival food. Little did we know that some lists and books consider the California bay tree to be a toxic plant. This includes the leaves that we so naively used as a free substitute in a sauce for spaghetti – long before it was called “pasta”.

Except for this uncontrollable twitch, I seem fine. So it probably didn’t effect me.

Please post a comment - I want to know what you think.

Visit my web site to learn about my new book on drip irrigation and other gardening books.

NOTE: The comments section at the bottom of the post has disappeared. Click on the "___ Comments" button or the title under the "Blog Archives". Thanks, Robert