Shifts in trophic interactions with forest type in soil generalist predators as indicated by complementary analyses of fatty acids and stable isotopes
Shifts in trophic interactions with forest type in soil generalist predators as indicated by complementary analyses of fatty acids and stable isotopes
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DOI：
10.1111/j.1600-0706.2013.00848.x
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发表时间：
2014-10-01
期刊：
影响因子：
3.4
通讯作者：
Scheu, Stefan
中科院分区：
文献类型：
--
作者：
Ferlian, Olga;Scheu, Stefan
人类对生态系统结构和功能的影响正在迅速增加。事实上，所有欧洲森林的管理都对食物网的多样性和结构产生重大影响。蜈蚣（Chilopoda：Lithobiidae）是欧洲温带森林土壤中丰富的节肢动物捕食者，具有普遍的摄食行为。然而，人们对蜈蚣猎物谱随土地利用的变化及其影响因素知之甚少。结合脂肪酸（FA）分析（可以确定不同猎物对捕食者营养的相对贡献）和稳定同位素分析（可以深入了解分解者食物网的营养结构），我们研究了不同年龄的山毛榉和云杉林中两种主要蜈蚣物种（Lithobius mutabilis 和 Lithobius crassipes）营养位的变化。两种蜈蚣物种的 FA 组成存在显着差异，与 L. mutabilis 相比，L. crassipes 中的细菌标记 FA 更为丰富。与山毛榉林相比，云杉林的差异最为明显。结果表明，针叶林中密集的针叶枯落物可能会限制较大的 L. mutabilis 的猎物可用性，并将觅食范围限制在枯落物表面，而较小的 L. crassipes 也能够利用较深层枯落物层的猎物。与 L. mutabilis 相比，Lithobius crassipes 的 N-15 和 C-13 含量明显更高，这表明与 L. mutabilis 相比，较小的 L. crassipes 占据更高的营养级，并且更多地依赖根部来源的碳。结果表明，蜈蚣的营养生态位在森林类型之间以物种特定的方式变化，身体大小和栖息地结构是猎物谱变化的主要决定因素。结合描绘捕食者与猎物相互作用的技术，可以深入了解温带森林土壤食物网中营养相互关系的变化及其驱动力。
Human impact on structure and functioning of ecosystems is rapidly increasing. Virtually all European forests are managed with major implications for diversity and structure of food webs. Centipedes (Chilopoda: Lithobiidae) are abundant arthropod predators in European temperate forest soils with a generalistic feeding behaviour. However, little is known on the variability in the prey spectrum of centipedes with land use and the responsible factors. Combining fatty acid (FA) analysis, which allows determination of the relative contribution of different prey to predator nutrition, and stable isotope analysis, providing insight into the trophic structure of decomposer food webs, we investigated variations in trophic niches of two dominant centipede species, Lithobius mutabilis and Lithobius crassipes, in differently aged beech and spruce forests. FA composition of the two centipede species differed significantly with bacterial marker FAs being more abundant in L. crassipes as compared to L. mutabilis. Differences were most pronounced in spruce as compared to beech forests. The results suggest that dense needle litter in coniferous forests may restrict prey availability to the larger L. mutabilis and confine foraging to the litter surface whereas the smaller L. crassipes is able to also exploit prey of deeper litter layers. Lithobius crassipes was significantly more enriched in N-15 and C-13 compared to L. mutabilis suggesting that, compared to L. mutabilis, the smaller L. crassipes occupies higher trophic levels and relies more on root derived carbon. The results indicate that trophic niches of centipedes vary in a species specific way between forest types with body size and habitat structure being major determinants of the variations in the prey spectrum. Combining techniques for delineating predator-prey interactions allowed insights into variations in trophic interrelationships and their driving forces in temperate forest soil food webs.