THE EFFECTS OF TREND AND FLUCTUATION OF CLIMATE CHANGE ON ECOSYSTEM PRODUCTIVITY

Climate change is closely related to trends and fluctuations. Assessing the consequences of these changes to terrestrial ecosystems requires an understanding of the action mechanism of these fractions, respectively. This study examined 11 years of remotely sensed-derived net primary productivity (NPP) to identify the impacts of the trends and fluctuations of temperature change on ecosystem productivity in Hunan province, China. A climatic signal decomposition and contribution assessment model was proposed to decompose temperature change into trend and fluctuation components. The results indicated that the mean contributions of the trend component of temperature change contributed 77% of the total NPP variation from 2001 to 2011 in Hunan province, whereas the fluctuation component explained the remaining 23% of the total NPP variation. The spatial variations of NPP in Hunan province indicated that the contributions of temperature fluctuation-driven NPP variation were higher in the north than in the south, and the contributions of temperature trend-driven NPP variation exhibited opposite characteristics. These results prove that the climatic trend change brought about great impacts on ecosystem productivity, and that climatic fluctuations can also alter the ecosystem succession process.