Changes in shoot allometry with increasing tree height in a tropical canopy species, Elateriospermum tapos
Changes in shoot allometry with increasing tree height in a tropical canopy species, Elateriospermum tapos
复制标题
DOI：
10.1093/treephys/22.9.625
复制
发表时间：
2002-06-01
期刊：
影响因子：
4
通讯作者：
Awang, M
中科院分区：
文献类型：
--
作者：
Osada, N;Takeda, H;Awang, M
对马来西亚林冠种Elateriospermum tapos B1的茎伸长单位（以下称为“current shoots”）异速生长进行了分析。(大戟科)。当前梢速异速随树高的增加而变化与树冠的生长和维持有关。总生物量、非光合器官与光合器官的生物量分配比、当期梢材密度与树高无关。树梢结构随树高的变化而变化。与矮树相比，高树产生的枝条质量相同，但茎粗短。细茎和长茎的水流嫩枝促进矮乔木的高度生长，而粗茎和短茎的水流嫩枝可减少高乔木的机械和水力应力。此外，与矮树相比，高树产生的current shoots叶片更多，干质量更低，面积更小，比叶面积（SLA）更小。矮树通过减少与大叶的相互遮阳来适应低光通量密度，具有较大的SLA。相比之下，高大的树木通过在茎的远端比近端产生更多的小叶子来减少茎内的相互遮阳。大量小叶子的产生促进了光线穿透到高大树木茂密的树冠。所有这些特征表明，随着树高的增加，当前茎部结构的变化是自适应的，使矮树能够最大限度地提高高度，使高树能够最大限度地捕获光。
Allometry of shoot extension units (hereafter termed "current shoots") was analyzed in a Malaysian canopy species, Elateriospermum tapos B1. (Euphorbiaceae). Changes in current shoot allometry with increasing tree height were related to growth and maintenance of tree crowns. Total biomass, biomass allocation ratio of non-photosynthetic to photosynthetic organs, and wood density of current shoots were unrelated to tree height. However, shoot structure changed with tree height. Compared with short trees, tall trees produced current shoots of the same mass but with thicker and shorter stems. Current shoots with thin and long stems enhanced height growth in short trees, whereas in tall trees, thick and short current shoots may reduce mechanical and hydraulic stresses. Furthermore, compared with short trees, tall trees produced current shoots with more leaves of lower dry mass, smaller area, and smaller specific leaf area (SLA). Short trees adapted to low light flux density by reducing mutual shading with large leaves having a large SLA. In contrast, tall trees reduced mutual shading within a shoot by producing more small leaves in distal than in proximal parts of the shoot stem. The production of a large number of small leaves promoted light penetration into the dense crowns of tall trees. All of these characteristics suggest that the change in current shoot structure with increasing tree height is adaptive in E. tapos, enabling short trees to maximize height growth and tall trees to maximize light capture.