PARENT SESSION
Oral Session # 26: Agro-Ecology II.
Presiding: K Gross
Tuesday, August 5. 1:30 PM to 5:00 PM, SITCC Meeting Room 100.

A legacy on the modern landscape of prehistoric farming in the Sonoran Desert of Arizona.

Schaafsma, Hoski^*,1, Briggs, John¹, ¹ Arizona State University, Tempe, Arizona

ABSTRACT- In order to measure the legacy effect of prehistoric farming in the extant plant community within the Sonoran Desert, research was conducted on prehistoric Hohokam agricultural fields (abandoned ca 750 years B.P.). Quarter-point sampling transects were used to sample the woody and cacti, plant communities, while the herbaceous plant community was sampled with 100m x 0.5m transects. Results from the point-quarter sampling provided data on spatial distribution and density of the woody and cacti communities on and off fields. Replicate off-field transects were located in similar geographic settings. Prehistoric farmers altered the soils on some fields, with little soil alteration on others. The total plant density for woody species on the soil-altered fields is estimated to be 822 plants/ha while a total plant density in off field locations is estimated at 4795 plants/ha, a large decrease in density on abandoned fields. Similar trends are documented in species richness. Fields with altered soils show a significant change (t = 4.53, p = .002) in the species density of modern vegetation over non-farmed areas. Fields with minimally altered soils exhibit little change in the modern plant community when compared to non-farmed areas. Thus the extant vegetation in the Sonoran Desert can be impacted by human activities occurring over 750 years ago.

Key words: Anthropogenic disturbance, Sonoran Desert, Legacy effects, Prehistoric agriculture