植物生态学报 ›› 2016, Vol. 40 ›› Issue (3): 212-220.doi: 10.17521/cjpe.2015.0255

• 研究论文 • 上一篇    下一篇

祁连山北坡霸王枝-叶性状关系的个体大小差异

杜晶, 赵成章(), 宋清华, 史元春, 王继伟, 陈静   

  1. 西北师范大学地理与环境科学学院, 甘肃省湿地资源保护与产业发展工程研究中心, 兰州 730070
  • 收稿日期:2015-07-06 修回日期:2016-01-07 出版日期:2016-04-11 发布日期:2016-03-25
  • 基金资助:
    基金项目 国家自然科学基金(41461013和91125014)。

Plant size differences with twig and leaf traits of Zygophyllum xanthoxylum in the northern slope of Qilian Mountains, China

Jing DU, Cheng-Zhang ZHAO(), Qing-Hua SONG, Yuan-Chun SHI, Ji-Wei WANG, Jing CHEN   

  1. Research Center of Wetland Resources Protection and Industrial Development Engineering of Gansu Province, College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China
  • Received:2015-07-06 Revised:2016-01-07 Online:2016-04-11 Published:2016-03-25

摘要:

枝与叶片权衡关系的个体大小差异性, 是物种形成不同冠层结构充分利用空间资源的一种策略, 有利于植株通过构型调整自身的光合效率和增强竞争力。在祁连山北坡荒漠草地, 根据体积将霸王(Zygophyllum xanthoxylum)分为3个大小等级(I级: (植株体积的立方根(d) ≤ 60 cm)、II级(60 cm < d ≤ 120 cm)和III级(d > 120 cm)), 采用标准化主轴估计方法, 研究了不同大小等级霸王种群枝长度与叶面积、叶数量的生长关系。结果表明: 随着植株大小等级增大, 霸王的枝长度、叶面积、枝横截面积逐渐增大, 叶数量呈逐渐减小趋势; 霸王枝长度的增长速度大于或等于叶面积的增长速度, 枝长度的增加速度大于叶数量的增加速度; 随着个体大小等级的增加, 霸王枝长度与叶面积的异速斜率、枝长度与叶数量回归方程的y轴截距均显著减小, 即植株叶面积与枝长度比值、叶数量的投入均显著降低。为提高资源利用效率, 霸王小个体植株倾向于短枝上着生大量的小叶, 大个体植株趋向于长枝上着生少量的大叶, 随植株大小等级增加, 叶面积增加而叶数量降低, 对小枝的资源配置具有一定的影响。

关键词: 大小等级, 霸王, 枝长度, 叶面积, 叶数量, 祁连山北坡

Abstract:
Aims Understanding the effects of plant size on the trade-off between twigs and leaves is important for revealing strategies of plants forming different canopy structure, making full use of space resources, and enhancing their photosynthetic efficiency and competitiveness with adjusting plant configuration. Our objective was to study how twig and leaf traits of Zygophyllum xanthoxylum depended on size in the northern slope of Qilian Mountains, China.
Methods The study was conducted in a desert grassland on the northern slope of the Qilian Mountains, Gansu Province, China. A transect was laid out horizontally along latitudinal direction, and three sample plots were set up along the transect at the interval of 50 m. Community traits were investigated by using double diagonal method, and all individuals of Z. xanthoxylum were used for measurement of the height, canopy, single leaf area, leaf numbers, twig length, cross-sectional area of twig, and bifurcation angle. Total of 90 plants were divided into different size classes based on the volume: d (the cube root of plant volume) ≤ 60 cm, 60 cm < d ≤ 120 cm, and d > 120 cm. Twig and leaf traits were log-transformed, and the standardized major axis (SMA) estimation method was used to examine the allometric relationships of twig length with leaf area or leaf number.
Important findings With the increase of plant size, the height, individual leaf area, twig length, and twig cross-sectional area of Z. xanthoxylum increased gradually (p < 0.01), while the bifurcation angle and leaf number decreased gradually (p < 0.01). An isometric or allometric relationship was found between twig length and leaf area in all plant size, whereas an allometric relationship was found between twig length and leaf number. The allometric slope between twig and leaf area was significantly decreased with the increase of plant size, the y-intercepts between twig and leaf number was significantly decreased too. To improve the efficiency of resource utilization, small individuals of Z. xanthoxylum tend to have a large number of leaves on short twigs, and large individuals have relatively few leaves on thick and long twigs. The increase of leaf area and the decrease of leaf number influenced the resource allocation pattern of twigs.

Key words: plant size, Zygophyllum xanthoxylum, twig length, leaf area, leaf number, northern slope of Qilian Mountains