Risk assessment of net primary productivity for wetland under climate change scenario: a case study of the Calamagrostis angustifolia wetland at Fujin in Sanjiang Plain, Northeast China
Using the BIOME-BGC model, we estimated the changes of net primary productivity (NPP) of Calamagrostis angustifolia wetland at Fujin City in the Sanjiang Plain under IPCC SRES emission scenarios (A1B, A2, B2), and assessed the wetland risk level based on the change ratios. Our results showed the optimal method significantly improved the simulation of wetland vegetation. From 2013 to 2042, wetland NPP was higher than that in 1961~1990. The NPP fluctuated strongly under A1B and B2 scenarios, while it showed a decreasing trend under A2 scenario. Risk assessment result indicates the risk of wetland under climatic change scenarios. In the A1B scenario, the number of high risk year might more than 6 in the next 30 years, and the risk of wetland might be lowest in A2scenario. In addition, precipitation was determined to be the dominant factor that affected NPP with significantly positive relationship (R~2=0.58, P<0.05). Although the increases in temperature and CO_2 concentration in the future climate are beneficial to plant growth, the wetland will face risk with the increases in extreme weather events and the intense climate change, especially for the greater fluctuation of precipitation. The protection and management of wetland should focus on water supply and deployment in the future.