1. We research application of GIS to the biogeochemical cycle of mercury.

2. Biogeochemical cycle The movement of chemical elements from the physical environment into organisms and back to the environment in a more or less circular pathway.

3. It discusses chemical forms, availability and biogeochemical cycle of selenium, and also analyses the relations between selenium and endemic disease and its important role in environment.

4. Two simple biogeochemical cycle models(PM and CM) were developed to demonstrate the influence of chromium on the biogeochemical cycle from human activities in this paper.

5. To determine how climate change alters this biogeochemical cycle in Arctic lakes, Drevnick's team analyzed sediment cores from nine lakes in the Canadian Arctic and in Svalbard, Norway.

6. A review on the research development of biogeochemical cycle of nitrogen was made.

7. To study the biogeochemical cycle of phosphorus, it is very important to accurately determine the concentration of orthophosphates in the surface of oceans, especially oligotrophic open-oceans.

8. The ecological reaction of all kinds of nitrogen in wetlands was analyzed and vistas on future research goal and study emphasis of nitrogen biogeochemical cycle were given.

9. Ecosystem element balance has been a main focus of global change ecology and biogeochemical cycle research.

10. Mercury methylation by microbes plays a key role in mercury biogeochemical cycle, and closely related with public health.

11. Now, more and more scientists pay their attention to the effects of dam reservoirs on the biogeochemical cycle of riverine nutrients and succedent aquatic ecological problems.

12. In all, it is significantly important for understanding the phosphorus species existed and the biogeochemical cycle of phosphorus in aquatic environment. 53 references were cited.