March 14, 2013, in the morning, Dr. Ronggang, the Environment and Climate Research Center, University of Lund, Sweden, visited the CEEP-BIT and gave an academic report entitled: A dynamic stochastic portfolio model for optimizing crop acreage and soil natural capital under multiple risks. Dr. Cong Ronggang has rich research experience. He was a visiting scholar at the Swedish University of Agricultural economic center, and a visiting scientist at University of Brandenburg, Germany. The report was hosted by Dr. Wang Ke. The CEEP teachers and students attended the lecture. Dr. Cong reviewed the importance of biodiversity to the ecosystem. Through dynamic stochastic modeling and using the Copula function method, his research considered the crop acreage, soil organic carbon, weather risk, market risk and other factors.