Chapter 38
Ecological Subregions of the United States

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Arizona-New Mexico Mountains Semi-Desert - Open Woodland - Coniferous Forest - Alpine Meadow

Two Sections have been delineated in this Province:

These Sections are located in Arizona and New Mexico. The area of these Sections is about 50,200 mi2 (130,000 km2).

Section M313A--White Mountain-San Francisco Peaks-Mogollon Rim

Geomorphology. Located in the Colorado Plateau physiographic province, this section is in central and eastern-central Arizona and west-central New Mexico. Geomorphic processes active in this Section include Cenozoic volcanism, including basaltic lava flows, cinder cone eruptions, and volcanic ash. Major landforms include mountains, plains, plateaus, and hills. Major landform features include the San Francisco Mountains, White Mountains, and Jemez and Mogollon Mountains. Elevation ranges from 6,000 to over 12,600 ft (1,820 to 3,860 m).

Lithology and Stratigraphy. There are Quaternary and upper Tertiary volcanic igneous rocks, with Middle Tertiary to Cretaceous metamorphics and Mesozoic sedimentaries.

Soil Taxa. Soils include Eutroboralfs and Ustochrepts with frigid soil temperature regimes and ustic soil moisture regimes. There are Glossoboralfs, Dystrochrepts, and Udic Argiborolls in frigid-udic regimes and Cryoboralfs, and Cryochrepts in cryic-udic regimes. There is a limited amount of pergelic-udic Cryumbrepts.

Potential Natural Vegetation. Predominant vegetation consists of ponderosa pine and gambel oak in frigid soil temperature and ustic soil moisture regimes, and white fir, Douglas-fir in frigid-udic regimes. Engelmann spruce and corkbark fir are in cryic-udic regimes and mountain avens are in pergelic-udic regimes.

Fauna. Reserved.

Climate. Precipitation ranges from 20 to over 32 in (500 to over 800 mm) annually, with more than half of the precipitation falling during the winter. Temperature ranges from less than 32 to 45 oF (less than 0 to 7 oC). The growing season ranges from less than 50 to 110 days, and winters are cold.

Surface Water Characteristics. This Section is the primary watershed for much of Arizona and western New Mexico. Several large streams are perennial. Much of the water is stored in reservoirs, and small artificial lakes are common. Ground water is limited and usually occurs at great depths.

Disturbance Regimes. Natural fires occurred in ponderosa pine about every 3 to 10 years, but have been prevented recently. This has led to a higher canopy cover and increased fuel loads, resulting in a less resilient ecosystem and increased hazard of wildfire. Much of this area is covered with timber, with rangeland and recreation being secondary uses.

Land Use. Reserved.

Cultural Ecology. This diverse Section encompasses primarily the mountainous ponderosa pine and transition zones of central Arizona and western New Mexico. Human groups have utilized this Section's well-watered upland valleys and meadows, high mesas, and more sparsely forested basins and ranges for the full extent of human prehistory in the Southwest. Paleo-Indian and Archaic peoples utilized the mountains seasonally for hunting and gathering, as did later populations. Early agriculturalists made use of a wide variety of settings, including upland valleys, for their pithouse villages and planting areas. In later times, settlements concentrated more in the bottomlands of major drainages, but shifts to higher elevations occurred at various times and in various places in response to climatic fluctuations, population growth, and defensive concerns. The uplands include manifestations of a wide range of cultural traditions, including the Sinagua, Mogollon, Mimbres, and eastern and western Anasazi. By the mid-1300's, however, most of the area was abandoned as permanent or seasonal settlements. Sometime around or before the Spanish entrada into the Southwest, Athabascan speakers made their appearance; Apache and Navajo continued to use the mountains for sustenance and for refuge well into the 19th century.

Spanish and Mexican use of most mountain areas was limited due to the presence of Apache and Navajo. In New Mexico, the Jemez Mountains were used by both Pueblos and Hispanic villagers for hunting, grazing, and fuel wood gathering in Colonial times. The discovery of mineral resources in the mid-1800's greatly increased American interest in the mountains, and military campaigns eventually removed the Apache and Navajo to reservations. The coming of the railroads in the 1880's made large-scale logging possible, especially evident in the White Mountains and Zuni Mountains. Ranching, mining, and logging were important pursuits in the early part of the 20th century, and continue today. Recreation and wilderness values are equally important on public lands. The mountains, particularly peaks like the San Francisco Peaks and Mt. Taylor, hold special cultural and religious significance for many contemporary Pueblos and tribes who continue to use the mountains for economic and ceremonial purposes. This Section includes portions of the White Mountain Apache, Navajo, and Jicarilla Apache Reservations, as well as Acoma, Laguna, Jemez, and Zia pueblos.

Compiled by Southwestern Region.

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Section M313B--Sacramento-Manzano Mountain

Geomorphology. This Section is in the Basin and Range physiographic province; it is located in central and south-central New Mexico. Major landforms are mountains, hills, plains, and scarps. Major landform features are the Sacramento, Manzano and Sandia Mountains and the Canadian Escarpment. Elevation ranges from 6,000 to 11,000 ft (2,130 to 3,690 m).

Lithology and Stratigraphy. There are Paleozoic sedimentary and Cenozoic aged igneous rocks and a few metamorphic rocks.

Soil Taxa. Soils include Eutroboralfs, Glossoboralfs, Dystrochrepts, Ustochrepts, Argiustolls, Calciustolls, Haplustolls, and Ustorthents with mesic and frigid temperature regimes and ustic and udic soil moisture regimes. A few Cryoboralfs and Cryochrepts occur with cryic soil temperature regimes and udic soil moisture regimes.

Potential Natural Vegetation. Vegetation consists of ponderosa pine in frigid soil temperature regimes and ustic and udic soil moisture regimes, Douglas-Fir in frigid-udic regimes, pinyon-juniper in mesic-ustic regimes, and Engelmann spruce, and subalpine fir in cryic-udic regimes. A few areas support grey oak at the lowest elevations.

Fauna. Reserved.

Climate. Precipitation ranges from 12 to 35 in (305 to 900 mm), with less than half of the precipitation falling during the winter. Temperature averages 40 to 57 oF (4 to 8 oC); winter temperatures vary throughout this Section. The growing season lasts less than 70 to 170 days.

Surface Water Characteristics. This Section supplies much of the water to the Rio Grande and Pecos Valley basins. Several streams are perennial.

Disturbance Regimes. Natural fire regime averages 3 to 10 years of frequency in ponderosa pine forests. Much of this area is covered with timber, with some areas of commercial quality. Another use of land is as range.

Land Use. Reserved.

Cultural Ecology. The earliest human occupation of the Sacramento-Manzano Mountain Section was characterized by an emphasis on big game hunting supplemented with gathering wild plant foods. Evidence for these activities is primarily restricted to the lower elevations and the base of the mountains. Around 6000 B.C., a gradual climate change from cooler and wetter to drier conditions resulted in a change of subsistence patterns. Highly mobile populations hunted and gathered a variety of resources throughout the region. The pinon-juniper zone was intensely exploited for both hunting and gathering. The mixed conifer forests were utilized to some extent for hunting and religious purposes, but the climate and scarcity of resources resulted in only sporadic use. As agriculture became important during the past 2000 years, most of the inhabitants became more sedentary and populations increased. Villages tended to be located close to water in the pinon-juniper woodland and lower alluvial fans at the base of the mountains. Athabascan groups entered the area sometime before the 1600's, utilizing many of the same resources; by the mid 1700's, Comanches occupied the plains immediately to the east. Today, Native Americans continue to use the mountains for gathering and ceremonial purposes.

The earliest historic settlement began in the late 1500's with the Spaniards. A few villages were established in the foothills of the Manzanos, Sandias, and near the headwaters of the Canadian and Pecos Rivers, but the Apaches kept most European settlers out of the Sacramentos and mountain ranges to the south. These settlers concentrated on the pinon-juniper woodlands and grasslands for hunting, fuel wood gathering, post cutting, and small subsistence farming. Beginning in the late 1800's, discoveries of gold and an increase in European settlement throughout the mountains resulted in more intensive use of the higher elevations for mining, logging, and ranching activities. Most of the homesteads and villages were located in the larger valleys or on the eastern slopes of the mountains near permanent water sources. By the turn of the century, logging dominated the activities in the mixed conifer zone, with ranching still playing an important role throughout the mountains. Currently, the area continues to consist primarily of small rural communities, with logging, fuel wood gathering, ranching, hunting, and recreation as the primary subsistence base. Anglo, Hispanic, and Mescalero Apache cultures are present. Recreational use has increased dramatically over the past few decades, particularly near the larger cities.

Compiled by Southwestern Region.

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