Changium smyrnioides Wolff. and Anthriscus sylvestris (L.) Hoffm. have similar photosynthetic characters; they use radiant energy in winter and early spring effectively, but cannot take full advantage of higher irradiance after spring. The specific leaf area (SLA), leaf area ratio (LAR), and leaf mass ratio (LMR) of C. smyrnioides were lower than those of A. sylvestris. The photosynthetic period of C smyrnioides was about 160 d shorter than that of A. sylvestris, causing the total photosynthetic production of C. smyrnioides to be lower than that of A. sylvestris. Hence if C. smyrnioides is disturbed, it could not recover within a short period. and J. Chang ... [et al.].
Three essentially different models of the galaxy distribution are currently in use: the supercluster model, the void model, and the sponge model. If the hard X-ray backgroud radiation in the sum of the radiation of unresolved discrete sources at large cosmological distances, then it is quite possible that these sources also exhibit the large scale structure of galaxies. The HEAO-A limits on the intensity fluctuations of the X-ray backgroimd are ušed to discriminate between three distribution models. These observations indicate a preference for the sponge-like model.