Photosynthetic differences contribute to competitive advantage of evergreen angiosperm trees over evergreen conifers in productive habitats
Photosynthetic differences contribute to competitive advantage of evergreen angiosperm trees over evergreen conifers in productive habitats
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DOI：
10.1046/j.1469-8137.2003.00879.x
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发表时间：
2003-11-01
期刊：
影响因子：
9.4
通讯作者：
Reich, PB
中科院分区：
文献类型：
--
作者：
Lusk, CH;Wright, I;Reich, PB
在这里，我们探讨了叶级气体交换性状在确定常绿被子植物和针叶树之间生长速率差异和竞争相互作用中的可能作用。我们比较了 23 个常绿被子植物和 20 个针叶树种群的太阳叶中光合能力 (A(max))、最大广告气孔导度 (G(s))、叶片寿命、氮浓度 (N) 和比叶面积 (SLA) 之间的关系。针叶树的叶子平均寿命（36个月）比被子植物的平均寿命（25个月）长。在标准化叶片N、A(质量)中，被子植物(56 nmol g(-1) s(-1))高于针叶树(36 nmol g(-1) s(-1))。 Stepwize 回归表明，光合氮利用效率的大部分差异可以通过 G(s) 和 SLA 来解释。被子植物的平均 G(s)（以面积为基础）高于针叶树（152 vs 117 mmol m(2) s(-1)），但两组的 A（面积）-G(s) 关系相似。在给定的叶N下，针叶树的SLA（投影面积基础）比被子植物低。光合作用差异可能有助于被子植物在生产性栖息地中相对于针叶树的竞争优势，并且可能与血管更大的水力容量有关，使被子植物能够形成更高的气孔导度，从而维持更高的蒸腾速率。
Here we explore the possible role of leaf-level gas exchange traits in determining growth rate differences and competitive interactions between evergreen angiosperms and conifers.We compared relationships among photosynthetic capacity (A(max)), maximum ad stomatal conductance (G(s)), leaf life span, nitrogen concentration (N) and specific leaf area (SLA), in sun leaves of 23 evergreen angiosperm and 20 conifer populations.Despite similar average leaf N(mass), conifer leaves lived longer on average (36 months) than angiosperms (25 months). At a standardized leaf N, A(mass) was higher in angiosperms (56 nmol g(-1) s(-1)) than in conifers (36 nmol g(-1) s(-1)). Stepwize regression suggested that most of this difference in photosynthetic nitrogen use efficiency could be explained by G(s) and SLA. Mean G(s) (on an area basis) of angiosperms was higher than that of conifers (152 vs 117 mmol m(2) s(-1)), but A(area)-G(s) relationships were similar for the two groups. At a given leaf N, conifers had lower SLA (projected area basis) than angiosperms.Photosynthetic differences probably contribute to the competitive advantage of angiosperm trees over conifers in productive habitats, and may be linked to the greater hydraulic capacity of vessels, enabling angiosperms to develop higher stomatal conductance and therefore sustain higher transpiration rates.