Nutrition of plants in a changing climate

Increasing levels of greenhouse gasses (e.g., CO2, N2O, CH4) in Earth’s atmosphere are elevating the planet’s temperature and modifying precipitation patterns. When coupled with additional, human-induced changes in nutrient cycles, including global increases in reactive nitrogen (N), these environmental changes can change biogeochemical cycling of nutrients and plant growth and modify plant nutrient uptake. Plant responses to elevated CO2 (eCO2) vary with functional group, with C3 plants impacted more than those possessing C4 photosynthesis. In general, uptake of most nutrients scales with changes in plant growth. Thus, CO2-enhanced growth of C3 plants generally requires a proportional increase in nutrient uptake. The exception to this is N; protein and N concentrations in leaves of C3 plants are often reduced at eCO2. This can translate to greater N-use efficiency. Soil nutrient cycles are also changing with global climate change (GCC). Decreased nutrient availability in root zones induced by GCC may restrict plant growth response to eCO2, and nutrient imbalances may lead to positive GCC feedbacks. Mineral composition of edible plant tissues (grains, fruits, etc.) can be altered in plants grown in eCO2, with commonly observed low concentrations of N, Fe, and Zn (mainly in C3 plants) leading to potential reductions of the nutritional value of food and feed.