柑桔增减产生态环境模式研究

AN INITIAL STUDY OF THE CITRUS HARVEST-ECOLOGY MODEL ASSOCIATED WITH ENVIRONMENTAL DISASTERS

Considering the main factors ofecological environment affecting citrus yield, based on the data from past three years observation of Wenzhou Citrus orchard in Kaihua village as a low hill-red soil ecological environment in the middle of the subtropical monson region, the statistical method was used to simulate the citrus harvest. The main factors of ecological environment associated with citrus yields in several key periods were as follow: cold injury leading to leaves drop in early or middle winter, anomalous high temperature to blame for blossoms or prematurea drop in May, and hot-dry weather affecting young citrus fruits in middle summer. Then, three sub-models to simulate the leaves drop in winter, the blossoms or prematures drop during late spring to early summer and the weigh per citurs fruit in summer-autumn were set up. A citrus yields-ecology model related to environmental disasters was then established. By using these models, the citrus yields of different habitat plots on gentle slope were simulated in 1986-1988 years. As a result, the difference in citrus yields between both test plots was obvious. The average yields per citrus tree of fall orchards in Jinhua in past 34 years were also simulated and those in 1990 and 1991 years were predicted.