We assessed the distribution of benthic macroinvertebrate at four surveying sites in Upo Wetland, a Ramsar site and the largest wetland in Korea, from February 2006 to November 2013. A long-term ecological monitoring was done monthly by using quantitative sampling method with dip net for analyzing the community change and correlation between the biodiversity and the environmental factors because environmental factors have a decisive effect on the community structure of the benthic macroinvertebrates. Total samples from the Upo Wetland area were classified into 3 phyla, 6 classes, 17 orders, 68 families, 176 species, and 25,720 individuals. Among the 176 species, 62 of the species had not been previously reported in this area. Asellus sp., Diplonychus esakii, and Gyraulus chinensis were the most common species in Upo Wetland. The change patterns of annual species diversity and species richness were calculated by using the average number of monthly occurring species and individuals. Diversity index increased from March to May and decreased after that showing lower diversity indices in July and August. It increased again in September and in October. Richness index showed similar tendency and fell around February and July, followed by a rising tendency around May and October. Correlation and regression analyses were performed with the change of biodiversity and each environmental factor. We found that water temperature have very significant positive correlation with species diversity in spring, and have significant indices in autumn and winter. On the other hand, precipitation showed a significantly negative correlation value in summer and autumn suggesting it has an effect on the community structure of benthic macroinvertebrates.

Abstract
 1. Introduction
 2. Materials and Methods
  2.1. Study site
  2.2. Environmental factors
  2.3. Sampling and analysis procedure
 3. Results
  3.1. Changes of environmental factors
  3.2. Benthic macroinvertebrates in Upo Wetland
  3.3. Patterns of community change
  3.4. Correlation and regression analyses
 4. Discussion
 5. Conclusion
 Acknowledgment
 REFERENCES

• Seon-Woo Cheong(Department of Biology & Chemistry, Changwon National University) Corresponding author
• Chun-Sik Yoon(Department of Biology & Chemistry, Changwon National University)
• Dong-Jun Lee(Department of Biology & Chemistry, Changwon National University)
• Hyoung-Gon Kim(Department of Biology & Chemistry, Changwon National University)