Relationship between wetland change and local climate in the semi-arid zone of the Songnen Plain

Wetlands are most sensitive to climate change, and their growth and decline can influence climate change. In order to express more intuitively the relationship between wetland change and a local climate in its semi-arid zone, the spatio-temporal characteristics of wetland change in the semi-arid zone of the Songnen Plain from 1985 to 2010 was studied, and the impact of large areas of wetland change on the local climate was analized by means of the empirical analysis and statistical method. Results showed that because of the increase of paddy fields, the total area of wetland in the studied area was on the rise. The wetland change produced an impact on the local climate, mainly on maximum temperature and precipitation during the period of May to September. The growth of the wetland area could reduce the increment of maximum temperature and the decrement of precipitation, and the decrease in wetland area could increase the increment of maximum temperature and decrement of precipitation. The changes in maximum temperature and precipitation corresponded respectively with wetland change in spatial distribution. Wetland change played a more important role in moderating local climate compared to the contribution of woodland and grassland change in the studied area. Therefore, the cold-humid effect of wetlands is the key factor in regulating local climates and mitigating climate warming.