Differential springtime branch warming controls intra-crown nitrogen allocation and leaf photosynthetic traits in understory saplings of a temperate deciduous species.
Differential springtime branch warming controls intra-crown nitrogen allocation and leaf photosynthetic traits in understory saplings of a temperate deciduous species.
复制标题
春季枝条变暖差异控制温带落叶树种林下幼树冠内氮分配和叶片光合特性。
DOI：
10.1007/s00442-021-04929-4
复制
发表时间：
2021
期刊：
影响因子：
2.7
通讯作者：
N.
中科院分区：
文献类型：
--
作者：
Osada;N.
对于温带落叶树来说，春季枝条间的氮竞争预计很重要，因为早期发芽的枝条中的氮分配高于发芽较晚的枝条。这种物候诱导的枝条相互作用会影响植物的光合作用，但这尚未得到评估。在落叶树种白蜡树的树苗中，对整个树冠（加热的树木；同一棵树的树干和所有树枝都加热）或部分树冠（加热的树枝和同一棵树上未加热的对照树枝）以及未加热的对照树进行了加热实验。研究春季叶片物候和叶片光合性状，以确定温度差异如何影响叶片物候和光合性状。发芽时间受温度影响——在温暖的树木和温暖的树枝中比对照树和对照树枝更早地发芽，但在对照树和对照树枝之间或在温暖的树木和温暖的树枝之间，发芽时间没有差异。相比之下，叶子性状受到树冠内物候变化的影响——变暖树枝的叶子的氮含量和光合能力高于对照树枝，但变暖树和对照树的叶子之间没有差异。因此，枝条变暖改变了变暖和未变暖枝条之间的氮分布，因为变暖的枝条发育得更快，导致叶片光合性状发生冠内变化。
Between-branch nitrogen competition is expected to be important during spring in temperate deciduous trees as nitrogen allocation would be higher in branches from earlier budburst than in those from later budburst. Such phenology-induced branch interaction would influence plant photosynthesis, but this has not been evaluated. Warming experiments were conducted on whole crowns (warmed trees; trunks and all branches of the same tree were warmed) or parts of the crowns (warmed branches with unwarmed control branches in the same tree), with unwarmed control trees, in saplings of the deciduous speciesFraxinus lanuginosa. Spring leaf phenology and leaf photosynthetic traits were investigated to determine how the difference in temperature affects leaf phenology and photosynthetic traits. The timing of budburst was influenced by temperature—budburst was earlier in warmed trees and warmed branches than in control trees and control branches, but budburst timing did not differ between control trees and control branches or between warmed trees and warmed branches. In contrast, leaf traits were affected by the variation in phenology within crowns—nitrogen content and photosynthetic capacity were greater in the leaves of the warmed branches than in the control branches, but they did not differ between the leaves of warmed trees and control trees. Thus, branch warming altered the distribution of nitrogen between warmed and unwarmed branches as warmed branches developed faster, resulting in intracrown variation in leaf photosynthetic traits.