Körner Ch, Bannister P, Mark A F
Institut für Botanik, Universität Innsbruck, Sternwartestrasse 15, A-6020, Innsbruck, Austria.
Department of Botany, University of Otago, Dunedin, New Zealand.
Oecologia. 1986 Jul;69(4):577-588. doi: 10.1007/BF00410366.
This study is part of a series of investigations on the influence of altitude on structure and function of plant leaves. Unlike most other mountain areas, the Southern Alps of New Zealand provide localities where physiologically effective moisture stress occurs neither at high nor at low elevation, but the changes in temperature and radiation with elevation are similar or even steeper than in most other regions. In comparison with results from other mountains, where moisture may impair plant functioning at low elevation, this study allows an estimation of the relative role of water for the expression of various leaf features typically associated with alpine plants. Maximum leaf diffusive conductance (g), leaf nitrogen content (LN), stomatal density (n) and distribution, as well as area (A), thickness (d) and specific area (SLA) of leaves were studied. Three different plant life forms were investigated over their full altitudinal range (m): trees, represented by Nothofagus menziesii (1,200 m), ericaceous dwarf shrubs (1,700 m), and herbaceous plants of the genus Ranunculus (2,500 m). In all three life forms g, LN, and n increased, while SLA and A decreased with elevation. Recent investigations have found similar trends in other mountains from the temperate zone, but the changes are larger in New Zealand than elsewhere. Herbs show the greatest differences, followed by shrubs and then trees.It is concluded that g is dependent upon light climate rather than water supply, whereas SLA and related structural features appear to be controlled by the temperature regime, as they show similar altitudinal changes under different light and moisture gradients. The higher leaf nitrogen content found at high elevations in all three life forms, suggests that metabolic activity of mature leaves is not restricted by low nitrogen supply at high altitude. In general, the leaves of herbaceous plants show more pronounced structural and functional changes with altitude than the leaves of shrubs and trees.
本研究是关于海拔对植物叶片结构和功能影响的一系列调查的一部分。与大多数其他山区不同，新西兰南阿尔卑斯山提供了这样的地点，即生理上有效的水分胁迫在高海拔和低海拔地区均未出现，但温度和辐射随海拔的变化与大多数其他地区相似甚至更陡峭。与其他山区的结果相比，在其他山区低海拔地区水分可能会损害植物功能，而本研究能够估计水分在通常与高山植物相关的各种叶片特征表达中的相对作用。研究了最大叶片扩散导度（g）、叶片氮含量（LN）、气孔密度（n）及其分布，以及叶片的面积（A）、厚度（d）和比叶面积（SLA）。研究了三种不同植物生活型在其整个海拔范围（米）内的情况：以麦氏假山毛榉（1200米）为代表的树木、欧石南亚高山矮灌木（1700米）和毛茛属草本植物（2500米）。在所有三种生活型中，g、LN和n均随海拔升高而增加，而SLA和A随海拔升高而降低。最近的调查在其他温带山区也发现了类似趋势，但新西兰的变化比其他地方更大。草本植物表现出的差异最大，其次是灌木，然后是树木。得出的结论是，g取决于光照气候而非水分供应，而SLA和相关结构特征似乎受温度状况控制，因为它们在不同光照和水分梯度下显示出相似的海拔变化。在所有三种生活型的高海拔地区发现的较高叶片氮含量表明，成熟叶片的代谢活动在高海拔地区不受低氮供应的限制。一般来说，草本植物的叶片随海拔变化表现出比灌木和树木的叶片更明显的结构和功能变化。
