Seven different tree-ring parameters (total ring width, earlywood width, latewood width, maximum latewood density, minimum earlywood density, average earlywood density, and average latewood density) were obtained from pink pine (Halocarpus biformis Hook.) at one chronology site in New Zealand (NZ). The chronologies were analyzed individually and then compared with each other. The relationships between the different tree-ring parameters and climate data (NZ average and local climate data) are also presented. There were more significant climate response functions in the NZ national average climate series than that of local climate data series. Earlywood-related parameters (earlywood width, minimum density, and average earlywood density) were more sensitive to climate than those of latewood. Temperature during the NZ growth season (November-March) was found to be the most strongly related to tree growth. This study demonstrates that the use of both ring width and ring density data can increase the climate information obtained from ring widths and should lead to improved paleoclimate reconstructions in New Zealand.
Ring characteristics of pine trees grown in polluted air showed up distinctly as a decrease in newly devised synthetic indicators such as product of W (relative ring width) and DD (relative difference between maximum and minimum density within a ring) or product of W and MD (relative mean density). Intensity of combined air pollution was estimated by the total of daily maximum concentration of SO2, ozone, NO2, and NO2. Since synthetic indicators show a significant correlation, at the over 98% confidence level, with the intensity of combined air pollution, phytotoxicity of air to pine growth must be attributable at least in part to combined effect of air pollutants.
To understand the growth patterns with respect to competition and leaf-mass increase in reproducing trees, growth allocation between height and stem diameter was examined for nonsuppressed reproducing Abies mariesii trees in a subalpine forest in northern Honshu, Japan. The growth allocation was analyzed by dividing the relative growth rate of the stem volume into the relative contributions of height and stem-diameter growth. During a 9-yr period, height growth and seed-cone production showed obvious annual variation, while stem-diameter growth recorded moderate variation. For two of three years of seed-cone production during the 9-yr period, trees with larger seed-cone production were associated with less height growth in the following year of seed-cone production; however, there was no trend of height growth in the year of seed-cone production. In the following year of mast seeding, trees with larger stem-volume growth were associated with less height growth. This trend was also shown for the relationship between the cumulative stem-volume growth during the 9-yr period and growth allocation to height, suggesting that trees with a larger biomass increase depress the allocation of photosynthate to competition with a large expenditure for reproduction. In contrast to this, trees with a smaller biomass increase might allocate photosynthate to competition with surrounding trees. The results of this study suggest that an increase in reproductive organs during life history and annual variation in reproduction are closely associated with the growth patterns of the stem in A. mariesii trees.
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