Relationships between stem-diameter growth periods and leaf growth periods of deciduous broadleaved tree species with reference to environmental factors

Abstract

Seasonal growth patterns of 19 deciduous broadleaved tree species were studied from 1984 through 1990. With the timings of diameter growths, each tree species had 10_??_20 day annual fluctuations over seven years. With the timings of leaf-flushes, there were 10 day annual fluctuations over three years. The annual variations of the timings of leaf-falls were only a few days in most species. Both in the stem diameters and leaf growths, the sequences of growth initiations or cessations of these species were kept in fairly constant orders. As for the relationships between stem-diameter growth and leaf growth, a clear difference was observed with the wood types. The ring-porous species, such as Quercus species, had earlier initiations of stem-diameter growths in a season, and the initiations preceded the leaf-flushes. On the contrary, the diffuse-porous species, such as Acer species, had later initiations in stem-diameter growths, and the leaf-flushes preceded the initiations of diameter growths. From results of an analysis of variance, the initiations of diameter growths of ring-porous species were related to minimum temperatures, and that of diffuse-porous species to the periods between leaf-flushes and initiations of diameter growths. The cessations of diameter growths of ringporous species were related to maximum temperatures, and that of diffuse-porous species to day-lengths. The leaf-flushes were related to the cumulative days of > 5°C mean temperatures and the precipitations. The leaf-falls were related to day-lengths.