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Earthworm (Lumbricus rubellus and Aporrectodea caliginosa) Effects on Carbon Flux in Soil
Author(s) -
Zhang Q. L.,
Hendrix P. F.
Publication year - 1995
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1995.03615995005900030026x
Subject(s) - lumbricus rubellus , earthworm , epigeal , lumbricidae , soil biology , litter , agronomy , chemistry , zoology , environmental chemistry , soil water , biology , botany , ecology
Effects of earthworm activities on litter and soil C flux were studied in a laboratory incubation experiment using two types of isotopic tracers and two earthworms with different ecological strategies‐ Lumbricus rubellus , an epigeic species, and Aporrectodea caliginosa , an endogeic species. The soil was prelabeled with 14 C. Dry sorghum [ Sorghum bicolor (L.) Moench] leaves labeled with 13 C were applied to the soil surface. Activity of both earthworm species significantly ( P < 0.001) enhanced total C efflux (479 ± 8 [standard error], 483 ± 4, and 395 ± 5 mg C jar −1 for L. rubellus, A. caliginosa , and the control, respectively) and significantly ( P < 0.05) reduced total surface soil microbial biomass (251.7, 205.2, and 312.1 mg C kg −1 soil for L. rubellus, A. caliginosa , and the control, respectively) during the 30‐d incubation. Activity of A. caliginosa also reduced subsurface soil microbial biomass. The epigeic earthworms assimilated significantly more 13 C from the litter and significantly less 14 C from the soil than the endogeic species. In the absence of earthworms, 14 C in the soil was translocated into the surface litter, as shown by a 15.5‐fold increase in 14 C enrichment in the surface litter by the end of the experiment. This translocation of soil C into the litter was significantly reduced by earthworm activities (155.43, 121.11, and 240.58 kBq kg −1 litter for L. rubellus, A. caliginosa , and the control, respectively), possibly due to disruption by earthworms of fungal‐hyphal connections between litter and soil. These interactions between earthworms and soil microbial processes have important implications for soil C turnover.