1. Flux of Root-Derived Carbon into the Nematode Micro-Food Web: A Comparison of Grassland and Agroforest.
- Author
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Hemmerling, Christin, Li, Zhipeng, Shi, Lingling, Pausch, Johanna, and Ruess, Liliane
- Subjects
GRASSLANDS ,WHITE clover ,RYEGRASSES ,GRASSLAND soils ,LOLIUM perenne ,NUTRIENT cycles - Abstract
Carbon (C) cycling is crucial to agroecosystem functioning. Important determinants for the belowground C flow are soil food webs, with microorganisms and microfaunal grazers, i.e., nematodes, as key biota. The present study investigates the incorporation of plant-derived C into the nematode micro-food web under two different cropping systems, grassland (ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.)) and agroforest (willow (Salix schwerinii Wolf and Salix viminalis L)). To quantify the C flux from the plant into the soil micro-food web, grass and willow were pulse-labeled with
13 CO2 and the incorporation of13 C into the nematode trophic groups was monitored 3, 7, 14 and 28 days after labeling. The natural stable isotope signals (13 C/12 C,15 N/14 N) were analyzed to determine the structure of the nematode micro-food web. The natural isotopic δ15 N signal revealed different trophic levels for omnivores and predators in grassland and agroforest soils. The incorporation of plant C into nematode tissue was detectable three days after13 CO2 labeling with the highest and fastest C allocation in plant feeders in grassland, and in fungal feeders in agroforest soil. C flux dynamics between the aboveground vegetation and belowground micro-food web varied with cropping system. This demonstrates that crop-specific translocation of C affects the multitrophic interactions in the root environment, which in turn can alter soil nutrient cycling. [ABSTRACT FROM AUTHOR]- Published
- 2022
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