Chaoqun Lu, research fellow in the International Center for Climate and Global Change and the School of Forestry and Wildlife Sciences, is one of the two winners of the Early Career Ecologist Award from the Ecological Society of America (ESA). Lu's research focuses on understanding and quantification of terrestrial ecosystem responses to multiple global changes by process-based ecosystem model development, application, and data-model assimilation.
In 2012, her pioneer work on reactive nitrogen enrichment and its role in carbon sequestration, greenhouse gas emission and food security in China generated a great deal of attention. According to Lu, the significant piece of this was based on a database outlining the magnitude and spatial-temporal patterns of nitrogen deposition and nitrogen fertilizer use across the whole of China. “That’s kind of the foundation,” she says. “We can use it to estimate the consequences and cost of nitrogen enrichment.” These costs include air and water pollution as well as contributions to climate change.
Lu used the DLEM model, developed by Hanqin Tian and the EDGE laboratory over the last decade, to flesh out the picture of nitrogen consequences. Tian’s group spent a great deal of time and effort to be sure the model represents the terrestrial nitrogen cycling and its interaction with the carbon and water cycles, which not all climate models take into account.
“The following up work is to estimate how much carbon sink is induced from atmospheric and anthropogenic nitrogen input and then we shift our focus to greenhouse gas emission. Nitrogen can stimulate plant growth and increase carbon sequestration, but also stimulates emission of nitrous oxide, a potent greenhouse gas. So there’s a dilemma in managing nitrogen,” says Lu. Her group was the first to definitively say that China has reached the tipping point – where nitrogen fertilizer use can no longer increase crop yield, but instead will stimulate warming. “It’s a very sensitive topic, I think,” she says.
Recently, her research in nitrogen cycling has expanded to the US, and contributed to EPA synthesis on nitrogen-climate interactions and evaluation of land-coastal linkage in the Gulf of Mexico. Lu has published 29 peer-reviewed papers in top journals such as Global Change Biology, Global Biogeochemical Cycle, Ecological Application, Journal of Geophysical Research, and Frontier of Ecology and the Environment. The one published in Journal of Geophysical Research has been cited over 100 times.