Incorporation of root-derived carbon into soil microarthropods varies between cropping systems

Zhipeng Li,Melanie M Pollierer,Stefan Scheu,Lingling Shi,Nicole Scheunemann,Anton M Potapov,Johanna Pausch

doi:10.1007/s00374-020-01467-8

Abstract

As the dynamics and magnitude of rhizodeposition vary considerably among cropping systems, we investigated effects of cropping system on the incorporation of root-derived carbon (C) into Collembola, a dominant taxon of soil microarthropods. In the field, we used 13CO2 to pulse label a crop monoculture (oilseed rape, Brassica napus L.), a mixed-grass community (dominated by Lolium perenne L. mixed with clover Trifolium repens L.), and a tree plantation (willow, Salix schwerinii E.L. Wolf and Salix viminalis L.). During 28 days, the incorporation of 13C was traced in nine species of Collembola including epedaphic (surface-dwelling), hemiedaphic (litter-dwelling), and euedaphic (soil-dwelling) functional groups. Incorporation of 13C into Collembola reached a plateau before day 3 after the labeling in grass and willow, but increased up to day 14 in rape. While euedaphic Collembola incorporated less root-derived C than epedaphic and hemiedaphic Collembola in rape and willow, the incorporation of 13C was similar among functional groups in grass. Differential incorporation of 13C in euedaphic species points to niche differentiation within the same functional group. Our findings highlight that cropping system not only affects the flux of root C into soil mesofauna, being slower in rape than in grass and willow, but also the utilization of root-derived resources by functional groups and species of Collembola. The results indicate that pronounced differences in belowground C inputs between cropping systems affect microbivores as basal species and thereby soil food webs and their functioning and services.

Highlights

Considerable amounts (10–20%) of C are released by plants into soil as rhizodeposition shortly after fixation (Kuzyakov and Domanski 2000; Dennis et al 2010)
13C incorporation was already high at day 3 and stayed relatively constant in most species except for L. paradoxus and O. villosa, which reached their peaks at days 7 and 14, respectively (Fig. 2)
Incorporation of 13C in willow was lowest in S. denisi and P. armata (Fig. 3)

Summary

Introduction

Considerable amounts (10–20%) of C are released by plants into soil as rhizodeposition shortly after fixation (Kuzyakov and Domanski 2000; Dennis et al 2010). This root-derived C comprises mainly low-molecular-weight compounds, such as glucose, organic acids, and amino acids, which are preferentially taken up by soil organisms (Dennis et al 2010). 1 J.F. Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Untere Karspüle 2, 37073 Göttingen, Germany. 3 A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninsky Prospect 33, 119071 Moscow, Russia

Methods

Results

Discussion

Conclusion