Say it isn’t so! This beautiful forest I look out onto every day is a forest of weeds? California white fir (Abies concolor) certainly does get a bad rap, its tarnished reputation stemming primarily from the subject of fire. White fir is easily destroyed by fire as its wood is soft, its bark relatively thin, and its lower branches provide an easy ladder for flames to climb. Yet here’s the conundrum — white fir grows best when it has fire to thin its stands. If fire is not prevalent or fire management keeps fires at bay, the tree can take over a forest and attract swaths of pests and diseases. The fir engraver beetle (Scolytus ventralis), better known as one of the bark beetles, causes high mortality in white fir stands. On the other hand, white fir is drought resistant and grows well in disturbed areas, thus the nickname “weed tree.” In our part of the Sierra, white fir mixes with red fir, ponderosa pine, sugar pine, and incense cedar.
Red fir (Abies magnifca) is not as vulnerable to fire as white fir. It’s stouter, with thicker bark. The red fir can grow up to 230 feet and 10 feet in diameter, whereas the white fir stands 60 to 200 feet high and up to 4 feet across. Red fir grows at higher elevations than white fir, although the two firs are often seen together. White fir is prevalent in Truckee.
The best way to identify the two firs is to look at the needles, which are shorter than pine needles. If the needles are flat with two white lines on their undersides and come out from the branch at a perfect right angle, the tree is a white fir. If the needles are four-sided, easy to roll between fingertips, and have a hockey stick-like curve where they attach to the branch, it’s a red fir. My secret mnemonic is that hockey is a bloody sport, hence red fir. White fir branchlets extend laterally as flat sprays, while red fir branchlets curve downwards then up at the ends. New growth in white fir — fluorescent, green fir needles — is soft and rubbery at the end of the branches and is edible with a limey, bitter taste; the new needles also smell citrusy. I often munch them along the trail, as do deer. The bark isn’t always easily comparable but the long, vertical plates on the white fir are white/gray and on the red fir, dark red/brown. Much easier to see are the colors underneath the outer bark, yellow-gold in the white fir and red-purple in the red fir.
And then the cones — they defy gravity! Hand-sized, barrel-shaped, the heavy cones stand upright on the tips of the branches. I saw a stand of firs once where the sun backlit the cones, highlighting them as if they were lit candles, which is often how we see firs, as perfectly shaped Christmas trees twinkling bright in our living rooms.
Do you have a question about our region’s natural world? Email mountainlife@moonshineink.com.
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