Nitrogen allocation and partitioning in invasive and native Eupatorium species
Nitrogen allocation and partitioning in invasive and native Eupatorium species
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入侵和本地紫茎泽兰物种中的氮分配和分配
DOI：
10.1111/j.1399-3054.2007.01019.x
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发表时间：
2008-03-01
影响因子：
6.4
通讯作者：
Feng, Yu-Long
中科院分区：
文献类型：
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作者：
Feng, Yu-Long
氮(N)分配给光合作用和防御之间存在一种权衡。由于天敌的缺乏，入侵物种可能会减少氮的防御分配。因此，我假设入侵物种可能比密切相关的本地物种分配更高比例的叶片总氮用于光合作用，并且具有更高的光饱和光合速率（P-max）和光合氮利用效率（PNUE）。为了验证这些假设，我们将入侵的紫茎泽兰与本地的紫茎泽兰和异叶泽兰在石灰岩灌木中进行了比较。与预期不同的是，入侵者分配给光合作用的叶片氮的比例并不比本地植物高。但其光合氮分配效率高于原生植株。它将更高比例的光合氮分配给羧基化，表现出更高的光合氮利用效率，而本地植物将更高比例的光合氮分配给捕光组分。叶片总氮含量在三种入侵种和本地种间差异不显著。对外来入侵植物而言，分配给羧基化的叶片氮的比例越高，导致羧基化、羧基化和生物能化过程中的氮含量越高，从而导致P-max的增加，从而提高PNUE、水分利用效率、呼吸效率和表观量子产率。这些生理优势及其较高的叶面积比可能是其入侵的主要原因。
There is a trade-off between nitrogen (N) allocation to photosynthesis and to defence. Invasive species may reduce N allocation to defence because of the absence of natural enemies. Thus, I hypothesised that invasive species may allocate a higher fraction of total leaf N to photosynthesis and have higher light-saturated photosynthetic rate (P-max) and photosynthetic N-use efficiency (PNUE) than closely related native species. To test these hypotheses, invasive Eupatorium adenophorum and native E. chinense and E. heterophyllum were compared in a limestone shrub. Unlike expectation, the invader did not allocate a higher fraction of leaf N to photosynthesis than the natives. However, it was more efficient in photosynthetic N partitioning than the natives. It partitioned a higher fraction of the photosynthetic N to carboxylation and showed higher use efficiency of the photosynthetic N, while the natives partitioned a higher fraction of the photosynthetic N to light-harvesting components. Total leaf N content was not significantly different among the three studied invasive and native species. For the invader, the higher fraction of leaf N allocated to carboxylation resulted in the higher N content in carboxylation and in both carboxylation and bioenergetics, which led to higher P-max, and therefore to higher PNUE, water-use efficiency, respiration efficiency and apparent quantum yield. These physiological advantages of the invader and its higher leaf area ratio may contribute to its invasiveness.