[Temporal and Spatial Evolution and Prediction of Ecosystem Carbon Storage in Jiangxi Province Based on PLUS-InVEST Model].

Land-use changes are an important factor affecting the change in carbon storage in terrestrial ecosystems. Exploring the relationship between land-use changes and carbon storage provides reliable data support for optimizing regional land-use structure and maintaining regional carbon balance. Taking Jiangxi Province as an example, we first analyzed the land-use changes; then simulated the land-use pattern under three scenarios (i.e., natural development, ecological priority, and economic development scenarios) in 2030 based on the PLUS model; and finally estimated the carbon storage change in the past (i.e., 1990-2020) and future periods (i.e., three scenarios in 2030) using the InVEST model, analyzed the spatial-temporal characteristics, and proposed the corresponding suggestions. The results showed:① The carbon storage in Jiangxi Province showed a downward trend from 1990 to 2020, with a total reduction of 4.58×107 t. The increase in the water bodies and construction land and the decrease in cultivated land, woodland, grassland, and unused land was the major cause. ② The carbon storage under natural development, ecological priority, and economic development scenarios in Jiangxi Province in 2030 were 2.20×109, 2.24×109 and 2.19×109 t, respectively. ③ The carbon storage under the three scenarios showed similar spatial characteristics, wherein the high carbon storage was distributed in northern, northwest, and western regions, and the low carbon storage was distributed near the central region. These results can provide data support for future land spatial planning and improving the carbon storage of terrestrial ecosystems in Jiangxi Province.

Determination of trace hydroxyl radicals by flow injection spectrofluorometry and its analytical application.

On the basis of the fluorescence increase of the reaction of ninhydrin with hydroxyl radicals, a new method for the determination of trace amounts of hydroxyl radicals by flow injection spectrofluorometry is presented. The introduction of flow injection analysis brought better reproducibility and avoided the effect of oxygen and other substances in the environment on the reaction of ninhydrin with hydroxyl radicals. Under optimum experimental conditions, the hydroxylated product of ninhydrin had excitation and emission maxima at 300 and 406 nm, respectively. The linear range was 2.60 x 10(-7) to 4.00 x 10(-5) M, and the limit of detection was 7.91 x 10(-8) M. A high analysis rate of 22 samples per hour was obtained. The proposed method has been applied successfully to the determination of scavenging effects of thiourea and vitamin C on hydroxyl radicals as well as to the evaluation of antioxidant capacities of some natural food.