Theoretical considerations concern the relationship between net primary productivity of natural vegetations and climatic conditions. Those suggest that net primary productivity (NPP) of natural vegetations linearly increases with increasing annual net radiation (Rn) and that the proportionality constant between Rn and NPP decreases very rapidly with increment of the value of radiative dryness index (RDI) that is the ratio of Rn to the product o£ annual precipitation and latent heat of evaporation. NPP data (682 set) of about 260 locations over the world were used to verify the theoretical prediction. A nonlinear regression equation describing the dependence of NPP on Rn and RDI was obtained and named "Chikugo model". The NPP-distribution map over Japan was made on the basis of the Chikugo model using the climatic data of Japan. It was found that NPP over Japan changes from about 8 t DW/(ha yr) in mountain districts of Hokkaido to about 18 t DW/ (ha yr) in southern coastal areas of Kyushu and Shikoku. These results agreed well with the net primary production of forests obtained by plant ecologists.

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Rice planthoppers are major pest for rice plants in Asian countries. They immigrates from overseas to Kyushu in Japan in the Baiu season every year. To predict the long distance migration of rice planthoppers to northern Kyushu, a migration model was developed with a hypothesis that rice planthoppers were transported by low-level jet stream at 1,000-2,000 m heights. The weather conditions for the migration period (June to July) were analyzed with the 850 mb chart at 21 h in 1980-1985 and at 09 h and 21 h in 1986, and possible migration days were decided. On the other hand, actual migration flight waves were decided with the number of catches by two nets. The possible migration flights decided by the weather chart agreed approximately with the actual flights. The accuracy of this prediction method was improved by using the 850 mb chart at 09 h additionaly. Finally, the prediction procedure was described.

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Fully aliphatic polyimides (APIs) have been synthesized. APIs were prepared by poly(addition-condensation) of the alicyclic dianhydride bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic 2,3:5,6-dianhydride with the aliphatic diamine 5-amino-1,3,3-trimethylcyclohexanemethylamine, the mixture of 2,5-and 2,6-bis(aminomethyl)bicyclo[2.2.1]heptane or 1,4-cyclohexanebis(methylamine) in m-cresol at high temperature. The polymerization proceeded smoothly at 200 • C and produced APIs with inherent viscosities up to 0.48 dl g −1 . The APIs were soluble in a wide range of polar solvents and showed high thermal stability and excellent transparency.

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