[Research progress on urban carbon fluxes based on eddy covariance technique].

Land use change and fossil fuel consumption due to urbanization have made significant effect on global carbon cycle and climate change. Accurate estimating and understanding of the carbon budget and its characteristics are the premises for studying carbon cycle and its driving mechanisms in urban system. Based on the theory of eddy covariance (EC) technique, the characteristics atmospheric boundary layer and carbon cycle in urban area, this study systematically reviewed the principles of CO2 flux monitoring in urban system with EC technique, and then summarized the problems faced in urban CO2 flux monitoring and the method for data processing and further assessment.

[Immune tolerance induced by bone marrow cell transplantation combined with use of cyclophosphamide in diabetic rats with pancreatic transplantation].

Objective: To study the immune tolerance induced by bone marrow cell transplantation combined with short-term use of cyclophosphamide after pancreatic transplantation in diabetic rats.

Methods: Type I diabetes mellitus was induced in BN rats with streptozotocin (STZ) intraperitoneal injection at a single dose of 45 mg/kg. Pancreatic transplantations were performed with the SD rats as donors and the diabetic BN rats as recipients.

[Effects of CO2 storage flux on carbon budget of forest ecosystem].

Carbon dioxide (CO2) storage flux in the air space below measurement height of eddy covariance is very important to correctly evaluate net ecosystem exchange of CO2 (NEE) between forest ecosystem and atmosphere. This study analyzed the dynamic variation of CO2 storage flux and its effects on the carbon budget of a temperate broad-leaved Korean pine mixed forest at Changbai Mountains, based on the eddy covariance flux data and the vertical profile of CO2 concentration data. The CO2 storage flux in this forest ecosystem had typical diurnal variation, with the maximum variation appeared during the transition from stable atmospheric layer to unstable atmospheric layer.

Spatio-temporal variability of soil respiration of forest ecosystems in China: influencing factors and evaluation model.

Understanding the influencing factors of the spatio-temporal variability of soil respiration (R (s)) across different ecosystems as well as the evaluation model of R (s) is critical to the accurate prediction of future changes in carbon exchange between ecosystems and the atmosphere. R (s) data from 50 different forest ecosystems in China were summarized and the influences of environmental variables on the spatio-temporal variability of R (s) were analyzed. The results showed that both the mean annual air temperature and precipitation were weakly correlated with annual R (s), but strongly with soil carbon turnover rate.