Carbon and nitrogen elemental and isotopic patterns in macrofungal sporocarps and trees in semiarid forests of the south‐western USA
Carbon and nitrogen elemental and isotopic patterns in macrofungal sporocarps and trees in semiarid forests of the south‐western USA
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美国西南部半干旱森林大型真菌子实体和树木的碳氮元素和同位素模式
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
Ron J. Deckert
中科院分区：
文献类型：
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作者：
S. Hart;C. Gehring;P. Selmants;Ron J. Deckert
总结
1以前在潮湿森林中的研究表明，13 C和15 N同位素组成在外生菌根（ECM）和腐生性（SAP）真菌之间存在差异，并且这种ECM-SAP“划分”可能为评估真菌营养状态提供有用的工具。
2我们评估了这种方法是否可以描述美国西南部两个半干旱温带森林中真菌的营养状态。这种技术可能是特别有价值的干旱地区，真菌的功能作用可能难以评估，因为不频繁的子实体生产。
3尽管δ 13 C值比δ 15 N值更能反映营养状态，但我们的数据与ECM-SAP分界线的存在是一致的。腐解真菌的δ 13 C值始终高于其假定的底物;然而，SAP子实体中的15 N富集程度差异很大。比较两个地点共有的11种子实体的δ 15 N值表明，尽管林下和林上常见树木的叶片的δ 15 N值相似，但其中一个森林的δ 15 N值较高。
4真菌子实体及其基质的同位素组成分析有助于阐明半干旱森林的生态关系。
Summary
1Previous studies in humid forests have shown that the 13C and 15N isotopic composition differs between ectomycorrhizal (ECM) and saprotrophic (SAP) fungi, and that this ECM–SAP ‘divide’ may provide a useful tool for evaluating fungal trophic status.
2We evaluated whether this method could delineate the trophic status of fungi in two semiarid, temperate forests of the south-western USA. This technique could be particularly valuable in arid regions where the functional roles of fungi can be difficult to assess because of infrequent sporocarp production.
3Our data were consistent with the existence of an ECM–SAP divide, although δ13C values were more useful than δ15N values in separating trophic status. Saprotrophic fungi consistently had higher δ13C values than their presumed substrates; however, the degree of 15N enrichment in SAP sporocarps was highly variable. Comparison of 11 sporocarp species common to both sites showed that δ15N values were higher in one of the forests, even though the δ15N values of foliage from common understorey and overstorey trees were similar between forests.
4We conclude that assessment of the isotopic compositions of fungal sporocarps and their substrates is helpful for elucidating ecological relationships in semiarid forests.