Nutrient-Induced Modifications of Wood Anatomical Traits of Alchornea lojaensis (Euphorbiaceae)
Nutrient-Induced Modifications of Wood Anatomical Traits of Alchornea lojaensis (Euphorbiaceae)
复制标题
DOI：
10.3389/feart.2016.00050
复制
发表时间：
2016-05
影响因子：
2.9
通讯作者：
Susanne Spannl;J. Homeier;A. Bräuning
中科院分区：
文献类型：
--
作者：
Susanne Spannl;J. Homeier;A. Bräuning
关于木本植物对未来热带森林大量营养元素氮（N）和磷（P）的高大气输入的响应，预计木本植物细胞水平上的木材解剖性状的适应性修改。作为一个跨学科的营养操纵实验（NUMEX）在厄瓜多尔南部进行的一部分，我们在这里提出的第一个描述性和定量木材解剖分析的热带万年青树种Alchornea lojaensis（大戟科）。我们取样的分支木材的9个单独的树木属于处理与N施肥，N+P施肥，和对照组分别。对11个不同的血管参数进行了定量评价。结果表明，该特有树种将能够很好地适应未来气候变化和更高的养分沉降的影响。这首先是由血管直径的增加和因此更高的理论值暗示的。区域特定的水力传导率，具有较高的养分有效性。其次，小血管（直径0-20µm）的百分比随着受精而显著增加。第三，在N和N+P添加后，血管排列（孤立血管与多血管分组）朝向较低的孤立血管分数（VS）百分比变化，同时朝向较高的总血管分组指数（VG）和较高的非孤立血管平均组大小（VM）。我们的结论是，较高的氮和N+P的养分供应引发较高的叶量和需水量，导致更大的船只空化风险较高。这是抵消了一个更强大的组合的船舶具有较小的气蚀风险，以确保供水在干燥的时期，预计将在不久的将来发生在更高的频率。
Regarding woody plant responses on higher atmospheric inputs of the macronutrients nitrogen (N) and phosphorous (P) on tropical forests in the future, an adaptive modification of wood anatomical traits on the cellular level of woody plants is expected. As part of an interdisciplinary nutrient manipulation experiment (NUMEX) carried out in Southern Ecuador, we present here the first descriptive and quantitative wood anatomical analysis of the tropical evergreen tree species Alchornea lojaensis (Euphorbiaceae). We sampled branch wood of nine individual trees belonging to treatments with N fertilization, N+P fertilization, and a control group, respectively. Quantitative evaluations of eleven different vessel parameters were conducted. The results showed that this endemic tree species will be able to adapt well to the future effects of climate change and higher nutrient deposition. This was firstly implied by an increase in vessel diameter and consequently a higher theo. area-specific hydraulic conductivity with higher nutrient availability. Secondly, the percentage of small vessels (0-20µm diameter) strongly increased with fertilization. Thirdly, the vessel arrangement (solitary vessels vs. multiple vessel groupings) changed towards a lower percentage of solitary vessel fraction (VS), and concurrently towards a higher total vessel grouping index (VG) and a higher mean group size of non-solitary vessels (VM) after N and N+P addition. We conclude that higher nutrient availability of N and N+P triggered higher foliage amount and water demand, leading to higher cavitation risk in larger vessels. This is counteracted by a stronger grouping of vessels with smaller risk of cavitation to ensure water supply during drier periods that are expected to occur in higher frequency in the near future.