不同供水条件对Ⅰ-69杨树材质的影响*

Influence of Water Supply on Wood Property of Populus deltoides

This paper intended to present the results of the series experiments conducted in Juxian County, Shandong Province, which aimed at determining the influence of water supply on wood property of Populus deltoides Bartr. cv. "Lux" I-69/55. In the spring of 1982, cuttings of the above-mentioned species were set with a spacing of 3×6 meters in the experimental field, which was later (during 1983 and 1986) divided into several small irrigation plots. Averaging about 0.45 hectare in size, each plot was supplied with a fixed quantity of water by means of dripping rainmaker systems; while the plots of the control only relied on natural rainfall. In contrast, the plots with lst-class water supply generally received artificially dripped water about 50 percent higher than the rainfall they received, and about 100 percent higher in regard to those with 2nd-class water supply of the same contrast. The results of the experiments, gained through three repetitions of the similar practice, indicated that irrigation could promote greatly the volume increment of this species without giving noticeable influences on such measurements of wood fiber as its length, width, cavum diameter, and double-wall thickness. However, it would lead a declining trend to most indexes of wood concerning its physical and mechanical properties, such as basic density, hardness, com-pressive strength, bending strength, shearing strength, and impact ductility.