坡向对冀北山地蒙古栎幼树生长及生物量分配的影响

Effects of aspect on growth and biomass allocation of Quercus mongolica saplings in the mountain area of northern Hebei Province,northern China

【目的】探讨冀北山地不同坡向对蒙古栎幼树生长及生物量分配的影响,旨在为该地区蒙古栎造林提供科学依据。【方法】本研究以冀北山地东坡、东南坡、西坡蒙古栎9年生幼树为研究对象,测定各坡向蒙古栎幼树地径、株高、冠幅及各器官生物量。采用单因素方差分析法检验各坡向蒙古栎幼树地径、株高、冠幅及生物量是否存在显著差异。以标准化主轴估计法检验各坡向蒙古栎幼树器官生物量间的异速生长关系。【结果】(1)东坡地径、株高均显著大于东南坡,其中地径差值0.29 cm,株高差值11.81 cm,两坡向间冠幅无显著差异。西坡地径、株高、冠幅均显著小于东坡和东南坡;地径-株高生长曲线斜率表现为东南坡(0.458)最大,东坡(0.377)居中,西坡(0.349)最小。(2)总生物量积累在东坡(1144.50 g/株)和东南坡(961.58 g/株)间无显著差异,西坡(365.33 g/株)显著小于东坡和东南坡;东坡和东南坡间叶、干、根生物量积累无显著差异,而东坡枝生物量积累(217.59 g/株)显著大于东南坡(159.17 g/株)。西坡各器官生物量积累均显著小于其他两坡向。(3)生物量分配比表现为西坡枝(13.32%)、干(24.10%)生物量分配比显著小于其他两坡向,而根生物量分配比(44.79%)显著大于其他两坡向(东坡34.28%;东南坡32.67%)。东坡枝生物量分配比显著大于东南坡,而叶分配比显著小于东南坡,干和根生物量分配比在东坡和东南坡间无显著差异。(4)各坡向成对器官生物量均呈等速生长关系,但呈现不同的器官分配趋向。【结论】蒙古栎幼树在3个坡向表现出不同的生长规律,东坡是蒙古栎幼树生长的最佳坡向。

[Objective]This paper aims to explore the effects of different aspects on the growth and biomass allocation of Quercus mongolica saplings in the mountain area of northern Hebei Province of northern China,so as to provide scientific basis for the afforestation of Quercus mongolica in the area.[Method]The 9-year-old Quercus mongolica saplings on the east,southeast and west aspects of the mountain area of northern Hebei Province were selected.The basal diameter,plant height,crown width and organ biomass were measured in different aspects.One-way analysis(AN_(O)VA)was used to test whether there were significant differences in basal diameter,plant height,crown width and biomass among the aspects.The method of standardized main axis estimation was used to test the allometric relationship between the organ biomass of Quercus mongolica saplings in different aspects.[Result](1)The basal diameter and plant height of the east aspect were significantly larger than those of the southeast aspect,with a difference of 0.29 cm in ground diameter and 11.81 cm in plant height.And there was no significant difference in crown width between the east aspect and the southeast aspect.The basal diameter,plant height and crown width of the west slope were significantly smaller than those of the east slope and the southeast slope.The slope of diameter-height curve was highest on the southeast slope(0.458),centered on the east slope(0.377),and lowest on the west slope(0.349).(2)There was no significant difference in total biomass accumulation between the east slope aspect(1144.50 g/tree)and the southeast aspect(961.58 g/tree),and the west aspect(365.33 g/tree)was significantly smaller than the east aspect and the southeast aspect.There was no significant difference in biomass accumulation of leaves,trunks,and roots between the east aspect and the southeast aspect.The biomass accumulation of stems on the east slope(217.59 g/tree)was significantly higher than that on the southeast slope(159.17 g/tree).The biomass accumulation of all organs on the west aspect was significantly lower than that on the other two slopes.(3)The biomass allocation ratio of stems(13.32%)and trunks(24.10%)on the west aspect was significantly lower than that on the other two aspects,while the root biomass allocation ratio on the west aspect(44.79%)was significantly higher than that on the other two slopes(east aspect 34.28%;southeast aspect 32.67%).The stem biomass allocation ratio on the east aspect was significantly higher than that on the southeast aspect,while the leaf allocation ratio on the eastern aspect was significantly lower than that on the southeast aspect.And the trunk and root allocation ratio had no significant difference between the east aspect and the southeast aspect.(4)The biomass of paired organs in each slope direction showed an isokinetic growth relationship,but it showed different organ allocation trends.[Conclusion]Quercus mongolica saplings show different growth patterns in the three slope directions,and the east aspect is the optimal aspect for it.