Intensification - Baja and California

A frequent theme of recent archaeological research in California has been the extent to which the phenomenon of intensification may account for the observed changes in prehistoric resource use. Intensification is commonly defined as an increase in the total resource yield from a given area that is achieved by accepting an increase in the unit cost of the recovered resources. Such an increased yield might have been achieved either by more thorough harvesting of previously exploited resources or by adding less profitable resources to the mix. One potential motive for intensification may be a regional population increase, either occurring as an independent variable or as an intentional response to competitive pressures. An alternative impetus may come from environmental deterioration and a reduced availability of preferred resources, occurring either naturally or as a result of human overexploittion.

An opposite process of deintensification may arise from a reduction of exploitation pressures on preferred natural resources. Locally, deintensification may have been associated with the emergence of more favorable climatic conditions after the end of the Medieval Climatic Anomaly (post ca. A.D. 1350) or with the hypothesized aboriginal demographic collapse caused by the introduction of Old World epidemic diseases during the protohistoric period (ca. A.D. 1520-1769) (Jones et al. 1999; Preston 2002).

Several archaeological patterns in San Diego County have been suggested as possible signs of intensification:

Early Holocene intensification seems to be implied by some models of regional culture history, in the shift from Paleoindian (San Dieguito) lifeways, thought to have been focused on hunting, to an Archaic (La Jolla) emphasis on seed grinding and shellfish collecting (e.g., Rogers 1966; Warren et al. 2008). However, some investigators have questioned the reality of a hunting focus for the San Dieguito Complex, and radiocarbon evidence seems to date some La Jolla shell middens and grinding assemblages nearly as early as the San Dieguito assemblages.
One explanation that has been offered elsewhere in southern California to account for a shift within shell middens from an Early Holocene focus on mussels (Mytilus spp.) to more extensive use of scallops (Argopecten aequisulcatus) and Venus clams (Chione spp.) during the Middle Holocene has been that the latter species were more labor-intensive to procure (Glassow 1997:158). A similar shift from mussels to scallops and clams has been documented in San Diego sites.
Middle Holocene kelp-bed fishing and sea mammal hunting has been seen as a form of maritime intensification (Masters and Gallegos 1997:20).
A decrease through time in the relative frequency of large mammal (especially deer) bones as compared with small mammal (lagomorph and rodent) bones in prehistoric archaeological deposits may indicate an intensification in hunting practices.
Late Prehistoric harvesting of the small bead clam (Donax gouldii) on the northern San Diego coast may represent intensified use of a resource that was relatively expensive either to collect or to process (Byrd 1998; Byrd and Reddy 2002; Laylander and Saunders 1993).
A late focus on acorns (Quercus spp.) as a major subsistence resource in prehistoric California has been widely interpreted as exemplifying intensification, because of the resource’s abundant availability but its presumed high processing costs (cf. Basgall 1987). Locally, D. L. True (1993) perceived a very late prehistoric intensification in the focus on acorn processing as contrasted with more generalized food processing during earlier times.
The exploitation of agave (Agave deserti) on the eastern margins of the Peninsular Range seems to have floresced during the final few centuries of prehistory (Shackley 1983, 1984). This may represent a new focus on the use of a relatively labor-intensive resource.
Environmental manipulation, most notably through the use of fire to promote the succession of favored flora and fauna, may be another case in which additional labor costs were accepted in order to increase the regional resource yields (Bean and Lawton 1973; Shipek 1993). Agriculture, if it was practiced prehistorically in San Diego County, would also likely represent a process of intensification.
The depression of particular resources, as evidenced in decreases in the average size of the individuals that were harvested, may be an archaeological indicator of overexploitation and intensification. L. Mark Raab (1997:33) saw evidence for the overexploitation of sea mammals, fish, birds, and shellfish on the southern Channel Islands. Conversely, increases in average size may indicate deintensification.
Deterioration of human health conditions that were related to nutrition might be an indirect indicator of resource intensification (e.g., Raab et al. 1994). Such a pattern does not seem to have been documented specifically in the San Diego area.

PROSPECTS

Future archaeological, paleoenvironmental, and replicative studies may be able to shed more light on the operation of processes of intensification and deintensification throughout San Diego prehistory. Changes in the resources that were used can often be documented archaeologically, but other kinds of studies may be necessary to establish the significance of such changes. Paleoenvironmental investigations may be able to document whether particular resources (such as acorns and bean clams) were present during the periods when they were not being heavily exploited. Replicative studies may be able to assess the relative costs of procuring and processing different resources, as well as whether those costs varied significantly depending on the technologies that were available. Physical anthropological studies may be able to evaluate the presence or absence of nutrition-related conditions in human remains from different time periods. Faunal studies may document changes in the average age or size of harvested animals as a possible index of resource depression.