Not long after the legions of Cortez laid siege to the Valley of Mexico in 1519, Old World peoples and organisms began to probe California’s frontiers. The earliest substantial visitation was the voyage of Juan Rodriguez Cabrillo in 1542-1543. Cabrillo’s exploration along California’s coast initiated landscape-altering processes that equaled if not surpassed those of the first people at the end of the Pleistocene epoch.
Cabrillo and his crews did not establish permanent settlements. However, his and other foreign explorations unwittingly introduced Old World germs and weeds to California during the period prior to the founding of the first mission 1769 (Erlandson and Bartoy 1995; 1996; Preston 1996; 2001). These organisms persisted, became naturalized, and radically changed the nature of land and life over much of the state. Afterwards, colonial settlers augmented these unintentional processes with conscious introductions of alien attitudes, settlement frameworks, a wide variety of domesticated plants and animals.
Californians and their environmental relationships were especially vulnerable to the exotic contagion that accompanied pre-mission explorations and colonial settlement (Preston 1996, 20-22). Diseases such as smallpox, measles, malaria, and virulent forms of syphilis progressively reduced native populations and destroyed traditional land use practices. As a consequence of reduced human predation, maritime and terrestrial game exploded in numbers and expanded spatially within native resource areas. Furthermore, native horticultural and associated practices such as burning, transplanting, and plant processing were disrupted and eventually terminated. These alterations resulted in more brushy understories in forests, changes in the distributions of some fire dependent plants, and extensive soil erosion caused by greater numbers of ungulates (McCarthy 1993, 223; McCullough 1997, 69; Preston 1997, 269-70, 277-81). In every environment where Native Californians were diminished or eliminated as top predator and keystone species, organic, hydrologic, and geologic aspects of the supporting ecosystem were altered (Garrott et al. 1993, 946).
The periodic forays to the state by foreigners prior to missionization also conveyed Old World weeds like wild oats and other Mediterranean annuals that spread rapidly and extensively at the expense of native species (Mensing and Byrne 1999). The transformation of California’s floral landscapes continued unabated during the colonial period. Indeed, Cabrillo and his associates initiated a process of botanical replacement that is still in progress today. As a result, approximately eighty to ninety percent of California’s contemporary grass and shrub lands are now covered with exotic plants, and about 17 percent of all plant species growing wild in the state are of non-native origin (Blumler 1995, 310; Stein et al. 2000, 135). Elna Bakker (1971, 149) stated that, ‘this successful invasion is one of the most striking examples of its kind to be found anywhere.” Alterations of California’s other visual signatures abound, most notably the golden color of the grasses that lie beneath the state’s oak groves during dry seasons. Californians deem it a quintessential characteristic of the state’s natural heritage. However, prior to the arrival of Cabrillo, these same vistas displayed greener hues owing to the prominence of indigenous perennial grasses. Furthermore, the regeneration capacity and current distribution of many of the oaks in these settings are influenced by greater soil moisture losses and an increased presence of rodents afforded by exotic grasses (Griffin 1980; Danielsen 1990, 59). The widespread encroachment of Old World invasives such as tumble weeds also influences the diversity and distribution of a wide selection of plants and animals that occupy California’s roadsides and wildland habitats. Relative differences in seasonal coverage and soil holding capacities between exotic grasses and indigenous species also have caused changes in runoff and associated soil erosion that have modified the appearance of some watersheds.
In addition to these unintentional invasives, Spanish exploration led to the introduction of a variety of domesticated plants and animals that comprise much of the state’s contemporary agricultural landscape. Although Native Californians cultivated a small number of food plants, modern agriculture in the state began with the first permanent settlement at San Diego in 1769 (Bolton 1949, 165, 174). An impressive array of Old and New World crops such as grapes, maize, wheat olives, and citrus were cultivated around the missions, pueblos, and presidios (Fig. 1) (Bryant 1967, 282, 316; Hornbeck 1983, 52-53). Later, Mexicans and Americans took note of these successful Spanish plantings and disseminated the crops and practices more widely throughout the state.
Figure . Mediterranean grasses sweep down to an orange grove on Highway 180 near the Sierra Nevada foothills. The influence of the Spanish extends well beyond the areas they actively settled and used. Photograph by W. Preston.
Colonial peoples also carried domesticated animals such as cattle, horses, sheep, and fowl to California. Livestock numbers quickly grew to enormous proportions in the mission realm and spread into the state’s interior (Hornbeck 1983, 54-55).The impacts of these animals on plants, animals, soils, and watersheds were additive to the changes wrought by the disruptions of wildlife (Burcham 1957, 186-88; Schoenherr 1992, 718). Periodic droughts exacerbated the devegetation and soil erosion caused by overstocked ranges (McCullough 1969, 15). Today, the residuals of these effects are still observed in much of the gullying found in the coastal ranges and on the margins of the Central Valley (Latta 1936).
The presence of colonial livestock influenced subsequent economic pursuits and their contemporary landscape expressions. Owing to the Spanish and Mexican preference for domesticated animals as well as their late colonial ubiquity, many early Americans viewed much of the state as suitable only for livestock ranching. As a result, the San Joaquin Valley was initially utilized as a great unregulated pasture (Preston 1981, 86-87). Many of the state’s lowlands have now been subsumed by other economic pursuits; however, the legacy of traditional livestock ranching remains visible in contemporary landscapes. One fifth of the state’s land is currently used for grazing livestock (Peters et al. 1998, 302) and their terraced trails show prominently on hillside lands. Barns, fences, and corrals are ubiquitous in many rural areas. California’s long history of ranching has altered a variety of physical environments that range from valley riparian areas to mountain meadows in the Sierra Nevada. The livestock industry accounts for the alfalfa and some of the feed such as yellow corn, that grace the state’s agricultural regions. Furthermore, livestock raising has directly contributed to the presence of thousands of small dams, ponds, and wells that appear on rangelands. Indeed, agriculture is the foremost consumer of fresh water in the state and the livestock industry demands the largest share of it (California Department of Water Resources 1998, 4-26).
The origin of many of the altitudes, practices, and institutions that have contributed to California’s evolving landscape can also be traced to the colonial of the Spanish. The Spanish as well as other foreign peoples arrived in the state with environmental attitudes that were considered different from those of the native inhabitants (Preston 1997, 264).
They viewed the state’s physical resources initially as inexhaustible and entirely divorced from their own spiritual existence. As a consequence, colonial people possessed few inhibitions about changing the physical environment for the purposes of settlement, economics, and sport. Both sustained commercial forestry and irrigation began in the colonial period (Clar 1959, 12-44; Hornbeck 1963, 51-53). Furthermore, some of the rules that governed the exploitation of natural resources survived to influence post-colonial landscapes. As David Hornbeck (1990, 51, 60) explains, the “principles of mining, irrigation, water, and property rights of women stem from the Spanish regime...and the large corporate farmers of California share in a common water-rights system that is a thinly disguised copy of Spanish water law. Indeed, the state’s ultimate adoption of “the doctrine of prior appropriation” as the legal framework for water use resembled the Spanish water law and allowed for the vast irrigated landscape currently observed (Hundley 1992, 72).
The initial Hispanic settlement infrastructure is also strongly reflected in California’s contemporary pattern of roads, settlements, tourist destinations, property boundaries, and architecture. A number of colonial transportation pathways provide routes for important highways and roads. The conformance of Highway 101 with long portions of El Camino Real is a noteworthy example. The pueblos, missions, and presidios served as nuclei for most of California’s largest urban areas. Today over seventy percent of the state’s population live in one of the twenty-eight sites originally founded by Spain (Hornbeck 1990, 61). Many of California’s twenty-one missions are important tourist destinations and they generate a host of landscape elements in the form of advertising and urban and roadside businesses. Furthermore, portions of the boundaries of many of the hundreds of ranchos that were granted during the colonial period have influenced the spatial patterns of countless urban and rural roads, fences, trees, power lines, and town boundaries in coastal regions such as the Santa Clara Valley (Broek 1932, 86, 94).
Most of the foregoing landscape expressions of California’s colonial past are restricted to the western portion of the state. However, the adoption of colonial themes in built environments is more spatially pervasive. The aesthetics of the Hispanic architectural legacy (e.g. mission revival, arroyo culture, and ranch-style houses) are significant and increasingly common attributes of domestic and commercial landscapes (Pitt 1970, 29l-96; Starr 1973, 390-414; Rice et al. 1996, 165). Housing tracts replete with red tile roofs and Hispanic decor for fast food outlets and banks are typical examples of the heritage, appeal, and timelessness of the state’s colonial legacy. (Figure 2) Also in many rural and urban areas are signature elements of a cultural scene created by todays Hispanic residents. Although most settled California after it became American, they represent continuity in Spanish heritage that lies heavily on the visible landscape.
Figure . The use of El Camino Real as a modern highway and Spanish style roofing in late twentieth century architecture are two persistent landscape legacies of Spain shown here in Atascadero. Photograph by W. Preston.
Figure 2. The use of El Camino Real as a modern highway and Spanish style roofing in late twentieth century architecture are two persistent landscape legacies of Spain shown here in Atascadero. Photograph by W. Preston.