Oaks Throw a Party
The Amazing Gambel Oak
It’s mid-May and the foothills are slathered in new stems, leaves and flowers of plants, all gleaming and waving in the breezes. The brightest and fastest-growing ones catch our eyes – deservedly so because their dazzling shows of vitality will fade as summer heat comes on and soil moisture departs.
Some of these are annuals that will live, reproduce and die over just a few weeks and then scatter their seeds to survive the alternately hot and frozen times until next spring (or the next, or the next …) when they’ll sprout and give it another try, from scratch. More are perennials that will grow a bit, and make some seeds, then senesce their above-ground parts and hunker down as living rootstocks, waiting out the hard times while maintaining a hold on their site that worked well enough this year, so with luck it will be good again next year.
And then there are the trees. A few maples make it in relatively shady and well-watered spots, but our dominant tree is the amazing Gambel oak (Quercus gambelii) that seems to flourish almost everywhere. Its secrets are extreme patience, and self-help. Like the perennial herbaceous plants, it favors its roots over all else. It also extends them horizontally and grows bulbous organs called lignotubers, in which it stores water and nutrients. These can be used to keep the stems alive, and under good conditions, to send up new ones.
This spreading strategy gives rise to scrubby clumps of stems called clones because they’re all the same genetic individual. But spreading is optional. We could find no evidence that clumps of Gambel oak on a hillside in Limekiln Gulch had grown at all during the 15 years between 2006 and 2021, from comparing their sizes in some high-resolution aerial survey photos to which the Salt Lake County Surveyor’s office kindly gave us access. In person, today, those clumps look perfectly healthy.
The photo above shows about 60 years of growth rings from near the base of a skinny 9-foot stem that was cut down during construction of the Avenues Ridge Trail above Morris’s Meadow. Rings from the last couple of decades (those in the light-colored sapwood) are extremely narrow, indicating little growth of that stem over many years. But it and its clone survived, presumably making a few acorns while waiting for better weather.
Among its other self-help skills, Gambel oak is remarkably good at allowing its sapwood to dry out and then refilling it when water becomes available. By shading the ground around its stems and maintaining an extensive root system, it creates islands of favorable habitat for itself, and incidentally for many small plants and arthropods such as the aphids that support much of the foothills ant community.
Jon Seger and Jack Longino
