Competition for nitrogen between adult European beech and its offspring is reduced by avoidance strategy
Competition for nitrogen between adult European beech and its offspring is reduced by avoidance strategy
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DOI：
10.1016/j.foreco.2011.01.035
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发表时间：
2011-07-15
影响因子：
3.7
通讯作者：
Rennenberg, Heinz
中科院分区：
文献类型：
--
作者：
Simon, Judy;Dannenmann, Michael;Rennenberg, Heinz
植物生长、繁殖和生物量分配可能受到氮素有效性的不同影响，具体取决于树木的大小和年龄。在这种情况下，可以通过不同植被成分(即幼苗、成熟树木、其他木本和草本林下植物)之间不同的氮素获取策略来避免对有限氮素的竞争。本研究通过田间试验研究了山毛榉森林不同植被组分之间对N的竞争是否通过N吸收的季节性时间和微生物N利用的影响而被阻止。为此，采用去除的方法研究了季节对成年山毛榉和山毛榉自然更新的氮素吸收和代谢产物的影响，以及土壤中无机氮的产生和利用的微生物过程。我们发现，无论使用何种氮源，自然更新的山毛榉和成熟的山毛榉之间对氮素的竞争都会通过季节性避免氮素吸收的策略(“良好的父母教养”)来减少。在春季，山毛榉幼苗对有机和无机氮的吸收能力显著高于成年山毛榉，而在秋季，成熟山毛榉对氮的吸收速率最高。去除植被组分不会导致土壤微生物氮过程在整个生长季中发生变化。因此，通过去除植被组分释放的N资源是边际的。土壤微生物N过程的这种一致性表明，植物和土壤微生物之间对N的竞争并不是通过在植被期间获取N的时机来避免的，而是存在于整个生长季。总而言之，所研究的森林生态系统中的氮素营养似乎与欧洲山毛榉有最佳的调谐。(C)2011爱思唯尔B.V.保留所有权利。
Plant growth, reproduction, and biomass allocation may be affected differently by nitrogen availability depending on tree size and age. In this context, competition for limited N may be avoided by different strategies of N acquisition between different vegetation components (i.e., seedlings, mature trees, other woody and herbaceous understorey). This study investigated in a field experiment whether the competition for N between different vegetation components in beech forests was prevented via seasonal timing of N uptake and affected by microbial N use. For this purpose, a removal approach was used to study the seasonal effects on N uptake and N metabolites in adult beech trees and beech natural regeneration, as well as soil microbial processes of inorganic N production and utilisation. We found that the competition for N between beech natural regeneration and mature beech trees was reduced by seasonal avoidance strategies ("good parenting") of N uptake regardless of the N sources used. In spring, organic and inorganic N uptake capacity was significantly higher in beech seedlings compared to adult beech trees, whereas in autumn mature beech trees showed the highest N uptake rates. Removal of vegetation components did not result in changes in soil microbial N processes in the course of the growing season. Thus, N resources released by the removal of vegetation components were marginal. This consistency in soil microbial N processes indicates that competition between plants and soil microorganisms for N was not avoided by timing of acquisition during the vegetation period, but existed during the entire growing season. In conclusion, N nutrition in the studied forest ecosystem seems to be optimally attuned to European beech. (C) 2011 Elsevier B.V. All rights reserved.