By ROBERT DRYJA
Los Alamos
We have been considering the different ecological strategies plants use for survival when living in canyons. Mulleins live for two years and produce an astonishing 100,000 to 200,000 seeds in their second year.
Coyote willows grow in a cluster of stems that typically live 10 years. Its seeds drift through the air as a part of a cottony wisp. Its seeds become more dispersed compared to mullein.
Both of these species grow close to water along stream sides.
Another species of plant does not depend on being close to water. Instead, it can grow along slopes at a distance from a canyon bottom. It also can grow in relatively shaded areas beneath trees. Gambol oak can be so common on slopes that it may not be noticed. It just is another bush or small tree among many. But something unusual can be seen.
Gambol oak often grows in small patches. A patch may have five to twenty plants and they are all approximately the same size. One patch may have plants standing two feet tall while a second patch has plants standing eight feet tall. The plants in these patches may be relatively close to one another.
What is causing this kind of growth?
Gambol oak produce acorns. However, acorns do not grow in clusters that can drop close together to create a patch. Additionally, a single acorn typically contains one seed within it, completely opposite to a mullein flower capsule. Acorns often are scavenged by birds or small mammals. Seeds therefore are spread randomly and widely, not remaining in a cluster.
A gambol oak grows an underground base called lignotuber. This base is like a bulb with a stem raising above it. A stem may be lost in a forest fire but the lignotuber can survive, protected underground.
Gambol oak also have a second kind of stem. It grows horizontally beneath the soil and is called rhizome. A rhizome grows vertical branches from its horizontal stem and these appear above ground.
What looks like several individual plants growing near one another are shoots from the same rhizome. A patch of gambol oak can actually be a single plant.
A stem or trunk growing above ground may be killed in a forest fire but the lignotuber and underground rhizomes are protected. A gambol oak has a combined survival strategy. Its relatively few seeds can be spread widely for growth in a variety of settings and does not need to be close to water. Its underground growth then helps it survive a forest fire if a fire occurs in a dryer environment.
Aspen trees grow at high elevations on mountains in the open sunlight while gambol oak grow at a lower elevation in shade. Aspen trees also grow underground rhizomes. Gambol oak and aspen trees both are the first to regrow in an area burnt by a forest fire. Aspen also have the distinction of being possibly the largest living organism. One grove occupies 108 acres and weighs an estimated 6,600 tons.
Its rhizome root system is estimated to have been growing for several thousand years.
Different species of plants have different strategies for survival. Mullein produce huge numbers of seeds. Coyote willow spreads its seeds through the air. Gambol oak and aspen trees grow stems underground.
A group of young gambol oak all about two feet tall are growing close together from an underground rhizome. Photo by Robert Dryja
A group of older gambol oak also are all of the same size, about eight feet tall and close together. Photo by Robert Dryja
Two acorns are growing on a gambol oak, typically with one seed inside each acorn. Photo by Robert Dryja
