Homing behaviour of Atlantic salmon during final phase of marine migration and river entry
Homing behaviour of Atlantic salmon during final phase of marine migration and river entry
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大西洋鲑鱼在海洋洄游和入河最后阶段的归巢行为
DOI：
10.1007/s00468-008-0246-3
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发表时间：
2013
影响因子：
2.4
通讯作者：
他3名
中科院分区：
文献类型：
--
作者：
Davidsen J.;Rikardsen A.;Thorstad E.;Halttunen E.;Mitamura H.;他3名
通过测量一种常绿木本植物 (Quercus glaucaThunb.) 和两种落叶木本植物 [Acer palmatumThunb.] 的叶片硝酸还原酶活性 (NRA)、叶片氮浓度和叶片扩张情况，研究了植物 NO3−N 使用的季节变化。和榉树(Thunb.) Makino]。所有物种的叶片氮浓度在叶片展开开始时最高，并在叶片展开过程中下降，直至叶片完全展开时达到稳定状态。所有物种的叶片NRA在展叶之初都非常低，随后迅速增加，随后又下降。所有物种的叶片 NRA 最高出现在展叶期中期，最低叶片 NRA 出现在夏季。叶片 NRA 与叶片扩展率呈显着正相关，而叶片 N 浓度与叶面积呈负相关。在常青树Q.青光眼，在叶开放前当前芽中的氮浓度增加；同时，1年生叶片中的氮浓度下降了25%。我们的结果表明，展叶期是阔叶树种 NO3−N 同化的最重要时期，并且展叶期叶片氮浓度的下降至少部分被当前叶片中新同化的 NO3−N 所补偿。
Seasonal changes in plant NO3−-N use were investigated by measuring leaf nitrate reductase activity (NRA), leaf N concentration, and leaf expansion in one evergreen woody species (Quercus glaucaThunb.) and two deciduous woody species [Acer palmatumThunb. andZelkova serrata(Thunb.) Makino]. Leaf N concentration was highest at the beginning of leaf expansion and decreased during the expansion process to a steady state at the point of full leaf expansion in all species. The leaf NRA of all species was very low at the beginning of leaf expansion, followed by a rapid increase and subsequent decrease. The highest leaf NRA was observed in the middle of the leaf-expansion period, and the lowest leaf NRA occurred in summer for all species. Significant positive correlations were detected between leaf NRA and leaf expansion rates, while leaf N concentrations were negatively correlated with leaf area. In the evergreenQ. glauca, the N concentration in current buds increased before leaves opened; concurrently, the N concentration in 1-year-old leaves decreased by 25%. Our results show that the leaf-expansion period is the most important period for NO3−-N assimilation by broadleaf tree species, and that decreases in leaf N concentration through the leaf-expansion period are at least partly compensated for by newly assimilated NO3−-N in current leaves.