CHAPTER 7 SUMMARY, CONCLUSIONS, AND CONSIDERATIONS SUMMARY Environmental History This study of the environmental history of the Middle For more than 450 years the ecosystems of the Middle Rio Grande Basin, which began in June 1994, is part of a Rio Grande Basin have evolved dynamically with the in- 5-year, multidisciplinary study under the auspices of the terrelated vagaries of climate, land forms, soils, fauna, USFS Rocky Mountain Forest and Range Experiment Sta- flora, and most importantly, human activities. Various tion, Albuquerque. The goal of the parent study is land use practices have caused an array of environmental problems. Activities such as grazing, irrigation farming, [t]o develop, synthesize, and apply new knowl- logging, and constructing flood control features, combined edge to aid in understanding processes, interac- with climatic fluctuations, have produced changes in tions, and sociocultural uses of upland and ri- stream flow-morphology, groundwater levels, topsoils, parian ecological systems for sustaining diverse, biotic communities, and individual species. Indigenous productive, and healthy plant, animal, and hu- human populations have, in turn, been impacted by modi- man populations and associated natural re- fications in these resources. These processes, impacts, and sources in the Rio Grande Basin (Finch and changes were discussed in Chapters 3–5. A summary of Tainter 1995: 1). this eco-cultural history is presented here. Droughts, floods, severe cold, and deep snow influ- This larger, ongoing study is based on the primary the- enced or directly impacted many activities, notably travel, sis that all ecosystems are anthropogenic to some extent agriculture, livestock raising, warfare, hunting, and gath- and cannot be understood without examining the role of ering during the historic period (A.D. 1540-present). human groups as components of and agents of impact on Occurring locally or regionally, droughts damaged or de- the environment. Environmental history not only em- stroyed crops and rangeland grasses, decimated wildlife braces this view but also the belief that interrelated “natu- populations, contributed to soil erosion, reduced stream ral” and human-induced impacts and changes in ecosys- flows, depleted water supplies, and contributed to the tem components can result in modified or abandoned occurrence of infectious diseases such as smallpox. These strategies of resource exploitation and even a shift in impacts sometimes resulted in widespread suffering, and “world view.” even loss of human life and the shifting of human popu- Within the parent study, four research areas or prob- lations. Historical documentation from the mid 17th cen- lems were defined, one being the need for an in-depth tury to the late 19th century substantiates more recent study of the environmental history of the Middle Rio detailed weather records, which indicate the occurrence Grande Basin, so as to better understand the interrelation- of a moderate to major drought in the region every 20 to ships of human populations and their environment. The 22 years. These periodic droughts, increasing use of sur- following spatial and temporal interrelationships were face and ground waters, and intensive grazing have gen- emphasized: (1) the role of various eco-cultures in adapt- erally resulted in dramatic changes in the flora. ing to and exploiting Basin ecosystems and associated The various effects of extended cold winters, or shorter resources, (2) the kind and extent of anthropogenic dis- periods of below-normal temperatures associated with turbances, (3) human responses to environmental changes, high winds and snow (blizzards) and above-normal snow- and (4) the sustainability of traditional activities of vari- falls, were also significant. Events such as these commonly ous groups in the Middle Basin. occurred during the “Little Ice Age,” which gripped New Based on extant knowledge and preliminary research, Mexico from about the mid 16th to mid 19th centuries. four spatial and temporal models of environmental change Adverse effects of this cold period included human fa- in the Middle Valley ecosystems were developed for test- talities, crop and livestock losses, and general unrest and ing (Scurlock 1995a: 20). In general, these models were suffering. The warming period and relatively frequent relatively accurate; however, a few modifications and re- droughts that followed, especially from the 1860s to the visions were made and are presented in the Conclusions 1950s, adversely impacted ranching and farming econom- section (pp. 389–390). ics as well, and human population shifts and trends. USDA Forest Service Gen. Tech. Rep. RMRS–GTR–5. 1998 385 Wildfires caused by lightning were a common phenom- Early Spanish contact with the Navajo and Apache in enon during the period of greatest lightning-strike fre- the study region soon erupted into a pattern of alternat- quency, July to September. The highest occurrence of these ing periods of peace and warfare. Their acquisition of the natural fires appears to be correlated with La Nina, or dry, horse from the Spanish made these two groups, as well as years. Native Americans used fire as one method of clear- the Southern Ute and the later-arriving Comanche, more ing the bosque for cultivation. Only in this century have mobile raiders and more successful hunters. Hides from naturally caused woodland or range fires on the adjacent bison, mule deer, pronghorn, and elk were obtained from grasslands been suppressed in the Middle Rio Grande these Indians by Spaniards through trade, including the Basin. In the late prehistoric and historic periods Native trade fairs held at Taos, Picuris, Pecos, and Abiquiu dur- Americans burned grasslands and woodlands to drive ing the colonial period. Captive Indians, usually boys or game animals to a location where they might be more eas- girls, were obtained in trade to work for governors in their ily killed, as well as to stimulate new plant growth. His- workshops weaving woolen goods or tanning hides. Girls panics used fire to create meadowlike conditions in were also used for various work in Spanish homes, where upland forests and to generate healthy grass growth on they were adopted. rangeland. In the late 16th century to early 17th centuries, the Range fires usually killed small woody species, whereas Spanish brought with them new technologies and a num- grass regeneration was stimulated. Removal of dense ber of new domesticated plants and animals, which had a stands of dry grasses by overgrazing also reduced avail- decisive impact on Pueblo, Navajo, and Apache diets and able fuel for range fires and decreased competition from the landscape. Introduced livestock included sheep, goats, grasses, allowing propagation and growth of woody horses, mules, burros, oxen, cattle, hogs, and chickens. plants. Woody shrubs and small tree species such as Introduction of metal tools such as the axe, which made fourwing saltbush, juniper, and pinyon have encroached cutting green wood easier and faster, as well as iron-tipped on semi-desert grasslands adjacent to the valley as a re- plows and various metal weapons, had a significant ad- sult of fire suppression. verse impact on surface water, fauna, flora, and soils. New Human-generated impacts have generally and ever- cultigens included wheat, barley, cabbage, onion, lettuce, increasingly altered the structure, function, and dynam- radish, cantaloupe, watermelon, and several species of ics of Basin ecosystems during the historic period. Some fruit trees, as well as native Mexican Indian crops such as activities, such as grazing and logging, have reduced veg- chile, cultivated tobacco, tomato, and new varieties of corn etative cover, and combined with periodic droughts and and beans. Some introduced non-cultigens, such as fires, have resulted in high rates of surface run-off due to alferillo and horehound, became established in fields and precipitation and associated erosion. Sediments from these other disturbed areas. events have, generally, increased through time, and the Hispano settlement patterns and land-water use, espe- resulting impacts on riparian plant and animal com- cially irrigation, generally were successful adaptations to munities have been, in cases such as the Middle Rio local ecosystems. Similar to Pueblo view and usage, Grande Valley and major tributaries such as the Rio Spanish colonial water law evolved to protect the com- Puerco, severe. Other human impacts, such as the in- munal interest rather than that of the individual. troduction of exotic species of plants and animals, use The relatively sharp increase in livestock numbers, es- of various toxins, diversion of water for irrigation, and pecially sheep, during this period was due to the growth construction of water control dams, have also brought in mining markets to the south in Mexico (and later Cali- dramatic changes to riparian ecosystems. Additional im- fornia). This intensive and widespread grazing resulted pacts on riparian communities, as well as on upland eco- in loss of vegetative cover and subsequent erosion in vari- systems—grasslands, pinyon-juniper and ponderosa ous locales. Grass shortages on Spanish land grants led, woodlands and montane mixed-conifer forests—are noted in part, to encroachment of Mexican flocks and herds on in the following overview. Pueblo crop and range lands, additional erosion of hill- Adverse impacts on all of the Middle Rio Grande Basin sides, and the siltation of river and stream beds and irri- Pueblos began with arrival of the first Spanish explorers gation facilities. in 1540. Hostilities against the Pueblos by these Europe- Limited mining in the colonial period by Spaniards and ans included war, rape, seizure of goods, burning of vil- Pueblos impacted local ecosystems. Perhaps the best lages, and sometimes involuntary use of individuals as known of these locales are the turquoise and lead mines guides or servants. Spanish colonization, which began in in the Cerrillos area, Tonque drainage, and the north end 1598, centered on the main pueblos along the Rio Grande of the Sandia Mountains. Pinyon, juniper, and oak were from Taos to Isleta, as well as the village of Acoma.