| The paper makes a study of the effect of UV-B enhancement on crop colony, othercreature and field climatic. The results show that enhanced or reduced UV-B radiation markedly effects development, the all indexes of productivity, colony struture, content of flavonoid and chlorophyll, yield of wheat. The study suggests that Logistic equation can simulate the growth of crop under normal condition, while Logistic equation and Gompertz formulation is preferential for the growth of the crop under stronger UV-B irradiation. Increased UV-B radiation can reduce weed number, aphid number, and animal number in soil, rust illness degree in wheatfield. Total solar radiation intension, UV-B radiation intension, temperature, humidity, wind speed, ground temperature in wheatfield are changed by enhanced UV-B radiation.The paper establishes the three subsystem models of farm ecosystem. The simulation date of crop's biomass under UV-B radiation enhancement is consistent with observation data.In this paper, the distribution of NPP of agriculture in China was given according to a new NPP model. This NPP model considers the effect of climate changes and Ozone reduction. The simulation resultion shows the crop productivity would decrease when precipitation and Ozone reduce. The decreased of crop productivity when Ozone reduce would are partly counteracted by temperature added. The crop productivity would increase when precipitation increases and ozone reduces. |
