Incorporation of plant carbon into the soil animal food web of an arable system
Incorporation of plant carbon into the soil animal food web of an arable system
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DOI：
10.1890/04-1728
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发表时间：
2006-01-01
期刊：
影响因子：
4.8
通讯作者：
Scheu, S
中科院分区：
文献类型：
--
作者：
Albers, D;Schaefer, M;Scheu, S
我们使用稳定同位素来研究植物碳进入农业系统的地下食物网。1999年5月，在哥廷根（德国北方）附近的黑麦田（Secale cereale）建立了地块并种植了玉米（Zea mays）。在1999年10月，2000年4月，2000年10月，中型和大型动物和玉米和黑麦凋落物收集在每个小区和分析C-13和N-15含量。N-15标记表明，分析的土壤动物物种跨越3个营养级的物种的营养地位变化不大的时间。调查的物种形成了一个连续的初级到二级分解者的捕食者。平均而言，捕食者物种不同的初级和次级分解者由3.9三角洲N-15表明，他们喂养的混合饮食的两个分解者组。对C-13和N-15特征的综合分析使我们能够确定猎物和消费物种之间的联系。1999年10月，玉米残留物被纳入地块后不久，玉米产生的碳存在于每一种被调查的动物物种中，包括顶级捕食者。在接下来的12个月里，玉米碳进入地下食物网的比例有所增加，但玉米碳的浓度在任何物种中都没有超过50%。此外，玉米出生的碳的物种的结合等级变化不大。研究结果表明，地下食物网严重依赖于来自最近两个生长季节之前的植物残留物的碳。在大多数物种的玉米出生的碳量不断增加，但是，在一些物种在冬季下降，这表明这些物种切换到饮食的基础上C3植物在冬季，或主要代谢碳纳入在过去的生长季节。该研究证明，在C4植物取代C3后，土壤无脊椎动物物种中C-13和N-15特征的综合分析是更好地了解地下食物网结构和碳通量的有力工具。
We used stable isotopes to examine the incorporation of plant carbon into the belowground food web of an agricultural system. Plots were established and planted with maize (Zea mays) in a rye field (Secale cereale) near Gottingen (northern Germany) in May 1999. In October 1999, April 2000, and October 2000, meso- and macrofauna and maize and rye litter were collected in each plot and analyzed for C-13 and N-15 content. N-15 signatures suggested that the soil animal species analyzed span three trophic levels with the trophic position of species varying little in time. The species investigated formed a continuum from primary to secondary decomposers to predators. On average, predator species differed from primary and secondary decomposers by 3.9 delta N-15 suggesting that they fed on a mixed diet of both decomposer groups. The combined analysis of C-13 and N-15 signatures allowed us to identify links between prey and consumer species. In October 1999, shortly after maize residues had been incorporated into the plots, maize-born carbon was present in each of the animal species investigated, including top predators. The incorporation of maize carbon into the belowground food web increased during the following 12 months but the concentration of maize-born carbon never exceeded 50% in any of the species. Furthermore, the ranks of the incorporation of maize-born carbon of the species changed little. The results suggest that the belowground food web relies heavily on carbon originating from plant residues from before the recent two growing seasons. In most species the amount of maize-born carbon increased continuously; however, in some species it decreased during winter, suggesting that these species switched to a diet based more on C3 plants during winter, or predominantly metabolized carbon incorporated during the last growing season. The study documents that the combined analysis of C-13 and N-15 signatures in soil invertebrate species, after replacement of C3 by C4 plants, is a powerful tool to better understand the structure of the belowground food web and the flux of carbon through it.