Direct uptake of soil nitrogen by mosses
Direct uptake of soil nitrogen by mosses
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DOI：
10.1098/rsbl.2006.0455
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发表时间：
2006-06-22
期刊：
影响因子：
3.3
通讯作者：
Bardgett, Richard D.
中科院分区：
文献类型：
--
作者：
Ayres, Edward;van der Wal, Rene;Bardgett, Richard D.
苔藓是最多样化和分布最广泛的植物群之一，通常构成山地、北方和北极生态系统的主要植被。然而，与高等植物不同，苔藓缺乏发达的根和维管系统，这被认为限制了它们对土壤养分的获取。在这里，我们使用稳定同位素技术 (N-15) 测试了两种生理学和分类学上不同的苔藓物种吸收天然完整草坪中土壤和湿沉积产生的氮 (N) 的能力。当暴露于土壤或湿沉积衍生的 N-15 时，这两个物种都表现出芽 N-15 浓度增加，这首次明确证明苔藓从土壤中获取氮。鉴于这些苔藓物种之间广泛的生理和分类差异，我们认为土壤氮吸收在苔藓中可能很常见，尽管需要进一步的研究来检验这一预测。苔藓物种对土壤氮的吸收可能使它们能够在广泛的生态系统中竞争土壤氮。此外，由于许多陆地生态系统的氮含量有限，苔藓对土壤氮的吸收可能会对植物群落结构和养分循环产生影响。最后，土壤氮吸收可能使某些苔藓物种面临比以前认为的更大的氮污染风险。
Mosses are one of the most diverse and widespread groups of plants and often form the dominant vegetation in montane, boreal and arctic ecosystems. However, unlike higher plants, mosses lack developed root and vascular systems, which is thought to limit their access to soil nutrients. Here, we test the ability of two physiologically and taxonomically distinct moss species to take up soil- and wet deposition-derived nitrogen (N) in natural intact turfs using stable isotopic techniques (N-15). Both species exhibited increased concentrations of shoot N-15 when exposed to either soil- or wet deposition-derived N-15, demonstrating conclusively and for the first time, that mosses derive N from the soil. Given the broad physiological and taxonomic differences between these moss species, we suggest soil N uptake may be common among mosses, although further studies are required to test this prediction. Soil N uptake by moss species may allow them to compete for soil N in a wide range of ecosystems. Moreover, since many terrestrial ecosystems are N limited, soil N uptake by mosses may have implications for plant community structure and nutrient cycling. Finally, soil N uptake may place some moss species at greater risk from N pollution than previously appreciated.