Sandias from Bosque by Rick Robb is licensed under a Creative Commons Attribution 3.0 Unported License.
(This paper was written for a class in 2005)
In an introduction to the recently published Field Guide to the Sandias, authors Robert Julyan and Sue Bohannon Mann inform us that the Albuquerque area is made up of seven different “life zones” or “vegetation zones.” Four of these zones occur within what is commonly accepted as the Sandia Mountain range. Our textbook discusses vertical zonation in which “significant elevational changes in short horizontal distances cause various plant associations to exist in relatively narrow zones on mountain slopes” (McKnight – 289). The concept is that there is a distinct correlation between altitudinal and poleward-longitudinal travel regarding floristic associations.
Julyan and Mann state that the change in vegetation experienced in traveling from the foothills to Sandia Crest is equivalent to driving along the California coast from San Diego north to British Colombia – about 1500 miles” (Julyan – 3).
The authors note that slope and exposure also influence where plants will occur within these zones. The ubec slopes on the north end tend to be cool and moist, whereas the south’s adret slopes are sunny and arid. Diverse soils, as well as a disturbance history, create hundreds of plant communities throughout the region. In addition, vegetation zones on the east side of the mountains will generally occur two hundred feet higher on the west side, due to the latter’s exposure and drier climate.
Zones designations in the Field Guide are based on the predominant tree species in a particular zone and roughly correspond with zones mentioned on page 290 in our textbook. At 6,000 to 7,500 feet is the Piñon-Juniper or “Upper Sonoran” zone. This most widespread of the state’s vegetation types is characterized by hot summers and mild winters, with moderate precipitation and high evaporation. Flowers, shrubs and grasses are extremely important in this zone for holding the soils and preventing erosion. Aside from its namesakes, typical fauna include various cacti, chamisa, Gambel oak and Apache plume. In areas of water, cottonwood and box elder will also appear.
At 7,500 to 8,200 feet is the Pine Forest zone. Also known as the Transition Zone, this region is marked by mild summers and cold winters. Larger Ponderosa pines becomes the dominant conifer, replacing the shrubbier piñon and juniper. This zone has the greatest species diversity in the Sandias, including wildflowers, New Mexico locusts, and riparian willows.
In the aptly-named Mixed Conifer zone we see the introduction of a variety of fir trees, including Douglas, white, and subalpine firs as well as Engelmann spruce and common juniper. Deciduous trees include Rocky Mountain maples and quaking aspen. The latter tend to occur in disturbed and transition areas. Also known as the Canadian zone or the Fir-Aspen belt, this zone occurs from 8,000 to 9,800 feet. As a result of cool summers and cold winters combined with significant precipitation, wildflower displays are much more frequent in this zone; penstemons, wild geraniums, columbines and wallflowers being predominant.
The Spruce-Fir zone tops out the Sandias. Engelmann spruce, white fir, corkback fir, Douglas fir and limber pine are the prevailing species. Dendrochronologists have dated some of the area’s limber pines to the 5th century c.e., as well as a Douglas fir to 995 c.e. Cool summers and long cold winters, combined with an average precipitation of 30 inches, make this zone an interesting contrast to the city it overlooks.
Julyan, Robert, and Sue Bohannon Mann. Field Guide to the Sandias. Ed. Robert Julyan and Mary Stuever. Albuquerque, NM: University of New Mexico Press, 2005
McKnight, Tom L., and Darrel Hess. Physical Geography: A Landscape Appreciation. 8th Ed. Upper Saddle River, NJ: Prentice Hall-Pearson, 2005