Seminar in PSA 106 at 3:40p.m.

ABSTRACT:

Crops obtain their major constituent - carbon (C) - from atmospheric carbon dioxide (CO2), but draw all other chemical elements largely from the soil. Concentrations of these elements, however, do not change in unison with steadily increasing CO2. Thus, relative to pre-industrial times, modern plants are experiencing a global elemental imbalance. Could this imbalance affect the elemental composition of plants, which provide 84% of all calorie intakes worldwide? The dietary deficiencies of iron (Fe), iodine (I), and zinc (Zn) are the leading nutritional disorder in the world, yet very little is known about the effects of elevated CO2 on the concentrations of these elements in plants. I will present an algebraic differential model based on the stoichiometric principles that quantifies the effects of high CO2 on the elemental composition of plants. The first compilation, to my knowledge, of published data supports the findings of the model and shows an overall decline in the concentrations of essential elements in plants. Therefore, elevated CO2 can intensify the already acute problem of micronutrient malnutrition.