Snow falls flake by flake, so it builds up around wildflowers and actually
protects them. They don't have large surfaces, and
their delicate stems bend easily to shake off any snow
that accumulates. Trees are different. The oaks have
rigid horizontal branches that collect large amounts
of heavy snow. Try holding a weight out at arm's
length for a full minute to appreciate the effect! Pines
are more protected by their shape and didn't suffer as
much damage. The forest will recover, but it will be
different. I think of this as evolution in action.
Notes:
The storm brought widow-makers for us, but it was a windfall for the tree trimmers.
Our road is now cleared (at great expense), but the woods are still a tangle of fallen branches.
The view from our house is changed. I'm worried about summer fires
with all the ladder fuel
on the ground that can carry fire up into the trees.
I feel vulnerable and exposed. Check out my snow pictures to see why.
I filled a kitchen measuring cup with snow from our porch and let it melt:
500 ml of snow made about 100 ml of water.
I have nothing to compare this to.
We had big fluffy snowflakes, but they were not
classic hexagons.
Later in the day (after the trees broke), it turned to corn snow.
There was no wind during our storm, which increased the damage since wind
would help shake the snow from the trees.
I noticed that different kinds of trees respond to
the snow event in different ways. These are first impressions.
My trail into the woods needs a lot of work before I can do more research!
The links are to my flora
which is under construction and may not work yet.
Visit CalFlora for more species info.
- The Coast Live Oaks (Quercus agrifolia)
were the hardest hit, no doubt because of their
broad stature and hard wood. Virtually every tree in the forest suffered some damage.
It was interesting that all the trees began to break about the same time,
suggesting that this is a simple matter of mechanical load. Most branches snapped
clean and either fell or made a hinge that left a widow-maker high in the tree.
- Our native Coulter Pines (Pinus coulteri)
came through the storm with little damage.
Pine needles don't accumulate much snow and the flexible branches can bend
under the weight to shake it off. The pyramidal shape allows the upper branches to clear the lower
when they drop their load. Wind would help this process, though our storm was still.
Be careful walking under pines with snow!
- Madrones (Arbutus menziesii)
suffered some damage, especially near our house where they are in the open.
Most trees survived intact. This surprised me at first since madrone wood is so hard and brittle.
These beautiful trees also have larger leaves than the oaks. It's my guess that the individual leaves
bend and drop their snow before damage occurs, whereas the smaller oak leaves overlap
and collect more snow en masse. The surface area of a leaf is a function of size squared,
but the snow accumulation is cubic. Slightly larger leaves collect much more snow individually,
which can help the tree give before it is broken.
Being able to give might be a better strategy than brute strength.
- Tanbark Oaks (Lithocarpus densiflora) came
through the storm without much damage.
They also have larger leaves than live oaks and a more pyramidal shape.
- Bay Trees (Umbellularia californica)
and Willows (Salix sp.) are so flexible that whole trees were bent down to the ground
across our road, but they didn't usually break.
I discovered the hard way that bay trees spring up with tremendous force when cut free.
This is pretty unnerving when working with a chain saw!
- Bigleaf Maples (Acer macrophyllum)
and Western Sycamores (Platanus racemosa)
are deciduous trees that didn't have their Spring leaves yet. They had no problems.
- Shrubs suffered most damage from falling oak branches. I did notice some
snow damage on the Greenbark Ceanothus (Ceanothus spinosus),
which has particularly hard and brittle wood.
It's not surprising that pines and large-leafed deciduous trees with a pyramidal shape
are dominant in the high mountains and further north. Regular snow storms could change
the makeup of our forest surprisingly fast since the replacement trees are already here.
This must be a reminder of past climates.
We had a similar snow storm on San Marcos Pass about 20 years ago in 1981 (also late spring? also La Niña?)
that did comparable damage.
Our recent storm would have been more damaging to our trees without this previous storm.
Old timers remember another heavy snow storm about 25 years before that.
The oak woodland is still here, so maybe this is a natural pruning cycle.
I hope it's not also part of a natural fire cycle.
I did an Alta Vista search on <"snow damage" and tree>
and got some hits, but nothing definitive.
