Trophic niche differentiation and utilisation of food resources in collembolans based on complementary analyses of fatty acids and stable isotopes
Trophic niche differentiation and utilisation of food resources in collembolans based on complementary analyses of fatty acids and stable isotopes
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DOI：
10.1016/j.soilbio.2014.12.012
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发表时间：
2015-03-01
影响因子：
9.7
通讯作者：
Scheu, Stefan
中科院分区：
文献类型：
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作者：
Ferlian, Olga;Klarner, Bernhard;Scheu, Stefan
弹尾目动物以各种资源为食，一直被认为是食物通才。然而，最近的稳定同位素分析表明，弹尾目动物物种占据着不同的营养水平，但对特定物种的食物资源的详细研究很少。此外，弹尾目动物物种的食物资源是恒定的还是随着栖息地的变化而变化的，目前还知之甚少。脂肪酸(FA)和稳定同位素分析可以分别洞察基础资源的利用情况和消费者的营养水平。我们结合这些方法研究了山毛榉和云杉林中六种弹尾目动物(绵毛鳞毛虫、四眼鳞毛虫、诺氏拟鳞毛虫、齿纹金龟子、小等托米藻和罗纳特型弹尾虫)的营养生态位的变化。我们将弹尾虫FA与各自研究地点的落叶微生物相关联，以确定与资源的联系。弹尾目动物的脂肪酸组成和稳定的同位素特征在不同森林类型之间没有显着差异，但在物种之间存在明显的营养生态位分化。齿纹扇贝和华山松的营养生态位相似，但与其他物种的营养生态位有显著差异，C-13和N-15特征耗竭最少。我们认为齿纹夜蛾具有捕食性的生活方式，以线虫为食。由于~(13)C和~(15)N含量处于中低水平和特定的脂肪酸组成，其他弹尾目动物可归因于次生分解者，其中小弹尾虫与细菌资源关系较密切，而四眼跳虫、羊毛虫和诺塔比利跳虫与真菌资源关系较密切。然而，饮食生态位可能包括多种资源，而不是单一的资源。弹尾目动物的Fas与凋落物中的Fas相关性较差，表明弹尾目动物的食性与散落落叶中微生物群落的结构有较大的独立性。结果表明，弹尾类动物消耗的资源是微小的场地而不是大量的物质，因此受益于土壤资源分布的小规模异质性。营养生态位随森林类型的变化很小，这表明这些微型站点在不同的森林中是相似的，并提供类似的食物。资源，尽管在凋落物和腐殖质结构方面存在显著差异。(C)2014爱思唯尔有限公司。保留所有权利。
Feeding on a variety of resources, collembolans have been assumed to be food generalists. However, recent stable isotope analyses documented that collembolan species occupy different trophic levels, but detailed studies on species-specific food resources are sparse. Further, it still is little understood whether food resources of collembolan species are constant or shift, e.g., with habitats. Fatty acid (FA) and stable isotope analysis allow insight into utilisation of basal resources and trophic levels of consumers, respectively. We combined these methods to investigate variations in trophic niches of six collembolan species (Lepidocyrtus lanuginosus, Folsomia quadrioculata, Parisotoma notabilis, Ceratophysella denticulata, Isotomiella minor and Protaphorura arrnata) in beech and spruce forests. We correlated collembolan FAs with that of litter microorganisms at the respective study sites to identify links to resources. FA composition and stable isotope signatures in collembolan species did not differ significantly between forest types but between species suggesting pronounced trophic niche differentiation between species. The trophic niche of C denticulata and P. armata was similar and significantly differed from the other species with C-13 and N-15 signatures being least depleted. We suggest that C. denticulata has a predatory life style feeding on nematodes. Due to intermediate to low 13C and 15N levels and specific FA compositions the other collembolan species could be ascribed to secondary decomposers with I. minor being more closely associated with bacterial resources and E quadrioculata, L. lanuginosus and P. notabilis with fungal resources. However, dietary niches presumably comprise a mixture of resources rather than single resources. FAs in collembolan species correlated poorly with those in litter suggesting that the diet of collembolan species is rather independent of the structure of microbial communities in bulk litter. The results suggest that collembolans consume resources of microsites rather than bulk material thereby benefitting from the small-scale heterogeneity in resource distribution in soil. Low variation in trophic niches with forest type suggests that these microsites are similar across different forests and provide similar food. resources despite marked differences in e.g., litter materials and humus structure. (c) 2014 Elsevier Ltd. All rights reserved.