Abstract:

Aims Our objectives were to illustrate inter-annual change of the productivity of three main vegetation types in the Liaohe Delta and to discover the driving factors resulting in the change of productivity.

Methods Principal component analysis, Pearson correlation analysis and partial correlation analysis were applied, based on data for 14-year yield of maize (Zea mays) and rice (Oryza sativa), 42-year productivity of common reed (Phragmites australis), and data on climatic factors, agricultural population, irrigation area and fertilizer use in the Liaohe Delta.

Important findings A slight increased yield of rice and maize was shown, but with obvious inter-annual fluctuation. However, a large increased yield of common reed was shown, but with slight inter-annual fluctuation. Climatic factors played an important role as the key factors for the inter-annual fluctuation of yield of maize and rice, while human factors (agricultural population, irrigation and fertilization) played a relatively small role. Both climatic factors and human factors (irrigation) played an important role in the inter-annual fluctuation of yield of common reed. Nevertheless, the three dominant vegetation types had different driving factors for their fluctuating yield. Annual hours of sunshine, annual precipitation and annual evaporation were identified as the mainly driving factors for the fluctuating yield of maize, rice and common reed, respectively.

Key words: climatic change, grain yield, Liaohe Delta, productivity, vegetation