Study On The Features Of The UV-B Radiation And Ecological Effects In North China Plain

A series of the solar radiation were made in the Gucheng Experimental Station. The basic characteristics and its ecological effects of the solar radiation are analysed connectrd with correlative studies home and abroad.The results shows that:①The basic characteristics and its ecological effects of solar spectral compositions,especially the photosynthetic active radiation(QPAR) and UV-B radiation are illuminated;②The daliy and annual variation of the solar global radiation(Q),the surface albedo and the net radiation(Rn) are analysed, include the variation intensity of the radioation separately;③The daliy and annual variation of the photosynthetic active radiation are analysed, given the probability distribution of the ratio of QPAR to Q (ηPAR) in different sample elements.ηPAR is 0.40 during whole year and is 0.41 during growth period (Mar. to Oct.).So, the analysis of the observation data gives that the computation formula which suitable to the North China plain: QPAR=0.40Q (during the whole year), QPAR=0.41Q (during the growth period). In this paper,the daliy and annual variation ofηPAR are analysed.In addiation,it discusses the impacts of cloud on the variation ofηPAR;④ηPAR(0.41)in this study was used to evaluate the potentiality of photosynthetic production in North China plain.The result is 27060～29520kg·hm-2。At the same time,we evaluate the efficiency of energy conversion of PAR in North China Plain;⑤The basic characteristic of ultraviolet radiation is expounded , then the daily and annual variation and intensity of UV-B radiation(QUV-B),the ratio of the UV-B radiation to the solar global radiation (ηUV-B) in North China Plain are analysed.Finally, we discuss the ecological security risk level of UV-B radiation,the factors of the radiation balance and the problem of ecological effects.