Dynamics of above-ground net primary production and its response to climate change in the Hunshandake sand

Using pasture observation data in an ecological meteorological field trial observatory in Duolun County during the period from 2004−2018, model parameters were initialized, model applicability was successfully tested, and the dynamic changes in simulated above-ground net primary production (ANPP), during 1961−2018, were studied in the Hunshandake sand. Model correction and validation results showed that the R² for the comparison of observed and simulated above-ground biomass was 0.78, slope b was 1.04, P was less than 0.01, the root mean square error was 25.23 g·m⁻² and the ratio of the absolute mean error was 45.76%. The model test results indicated that the CENTURY model can simulate dynamic changes in above-ground biomass in the Hunshandake sand. The climatic variations since 1961 in this study area were analyzed in this paper. The results indicated that the annual average temperature and extreme annual maximum temperature had an obvious increasing trend; the rates of increase were 0.4 ℃·(10 a)⁻¹ and 0.3 ℃·(10 a)⁻¹ respectively. Annual and growing seasonal precipitation and ANPP did not show significant tendency of variation. Factor analyses showed that increasing temperature was the main characteristic of effect of climate change in sand. Pearson correlation analysis indicated that ANPP was highly significantly correlated with the main growing season precipitation and extreme annual maximum temperature, which were critical meteorological factors affecting ANPP in the Hunshandake sand.