The edible plant Dichelostemma capitatum: Its vegetative reproduction response to different indigenous harvesting regimes in California

To more thoroughly understand the ecological effects of harvesting geophyte s for food by American Indians, an investigation of the ethnobotany and pop ulation dynamics of Dichelostemma capitatum (blue dicks), an attractive sou rce of nutrition to many California Indian groups was undertaken. Some cult ural groups harvest the corms and replant the cormlets, spare plants, and h arvest after seeding to ensure replenishment of seed. Some Indian elders eq uate judicious harvesting with the maintenance and enhancement of field pop ulations of this geophyte. A field experiment was conducted to determine th e degree to which differences in intensity and timing of harvest, with and without replanting of cormlets, have any effect on corm and cormlet product ion. We found that harvesting at 100% intensity, through digging up all pla nts and corms, and without replanting cormlets at the seed stage, significa ntly reduces numbers of corms and cormlets compared to the controls (no har vest). However, harvesting at 50% intensity, through digging up half of all plants and corms at the flowering or seed stages, without replanting corml ets, was not significantly different from the controls (no harvest). The re sults suggest that harvesting blue dicks corms with a digging stick in the latter way could yield a sustainable level of harvest. Indigenous harvestin g and management regimes may offer some of the best examples of long-term u ses and management of the regional flora without detriment to its biodivers ity. Restorationists are urged to study and experimentally mimic indigenous disturbance regimes and their ecological effects known to occur historical ly in various ecosystems. In some cases, areas will greatly benefit from th e reintroduction of management and harvesting regimes that authentically si mulate ancient indigenous interactions.