Achievement

Trainee Laci Gerhard and IGERT participating faculty member, Joy Ward published a paper, "Plant Responses to Low CO2 of the Past," in New Phytologist 188 (2010):674-695. They found that during the Last Glacial Maximum (LGM; 18 000–20 000 yr ago) and previous glacial periods, atmospheric [CO2] dropped to 180–190 ppm, which is among the lowest concentrations that occurred during the evolution of land plants. Modern atmospheric CO2 concentrations ([CO2]) are more than twice those of the LGM and 45% higher than pre-industrial concentrations. Since CO2 is the carbon source for photosynthesis, lower carbon availability during glacial periods likely had a major impact on plant productivity and evolution. It is clear that the influence of low [CO2] transcends several scales, ranging from physiological effects on individual plants to changes in ecosystem functioning, and may have even influenced the development of early human cultures (via the timing of agriculture).