Ayres Edward, van der Wal René, Sommerkorn Martin, Bardgett Richard D
Lancaster University, Soil and Ecosystem Ecology Laboratory, Institute of Environmental and Natural Sciences, Lancaster LA1 4YQ, UK.
Biol Lett. 2006 Jun 22;2(2):286-8. doi: 10.1098/rsbl.2006.0455.
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 (15N). Both species exhibited increased concentrations of shoot 15N when exposed to either soil- or wet deposition-derived 15N, 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.
苔藓是植物中种类最多、分布最广的类群之一，常构成山地、北方和北极生态系统中的优势植被。然而，与高等植物不同，苔藓缺乏发达的根系和维管系统，这被认为限制了它们获取土壤养分的能力。在此，我们运用稳定同位素技术（¹⁵N），测试了两种在生理和分类学上不同的苔藓物种从天然完整草皮中吸收土壤和湿沉降来源氮（N）的能力。当暴露于土壤或湿沉降来源的¹⁵N时，这两种苔藓的地上部分¹⁵N浓度均有所增加，首次确凿地证明了苔藓能从土壤中获取氮。鉴于这两种苔藓物种在生理和分类学上存在广泛差异，我们认为苔藓吸收土壤氮可能较为普遍，不过还需进一步研究来验证这一预测。苔藓物种吸收土壤氮可能使它们在多种生态系统中竞争土壤氮。此外，由于许多陆地生态系统受氮限制，苔藓吸收土壤氮可能对植物群落结构和养分循环产生影响。最后，吸收土壤氮可能使一些苔藓物种面临比之前认为的更大的氮污染风险。
