Protozoan Pulses Unveil Their Pivotal Position Within the Soil Food Web

• Published in: Microbial ecology 2012-05, Vol.63 (4), p.905-918
• Main Authors: Crotty, Felicity V., Adl, Sina M., Blackshaw, Rod P., Murray, Philip J.
• Format: Article
• Language: English
• Subjects: Animals; Apes; Arthropods - physiology; Biological and medical sciences; Biomedical and Life Sciences; Ciliophora - physiology; Collembola; Ecology; Ecosystem; Eukaryota - physiology; Food; Food Chain; Forest soils; Fundamental and applied biological sciences. Psychology; Geoecology/Natural Processes; Grasses; Grassland soils; Grasslands; Habitats; Insecta - physiology; INVERTEBRATE MICROBIOLOGY; Invertebrates; Land management; Larvae; Life Sciences; Microbial Ecology; Microbiology; Mineralization; Nature Conservation; Nematoda; Nematoda - physiology; Oligochaeta - physiology; Protozoa; Soil - parasitology; Soil fauna; Soil food webs; Soil nutrients; Soil types; Water Quality/Water Pollution; Woodland soils; Woodlands
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/s00248-011-9956-y

Protozoa are one of the most abundant groups of bacterivores within the soil and are responsible for mineralisation of bacterial biomass, having a large impact on C and N cycling. Little is known of their contribution to soil nutrient transfers or the identity of their consumers. Here, for the first time indigenous flagellates and ciliates, enriched to 83 atom% for ¹³C and 10 atom% for ¹⁵N, were introduced to soil cores from two different land managements, grassland and woodland with the same soil type, to trace the flow of protozoan C and Í through the soil food web. Nematodes, Collembola, earthworms and insect larvae obtained the greatest amounts of C and N of protozoan origin, either through direct consumption or uptake of biomass post-cell death. Our results show that changes in management, affect the functioning of the soil food web and the utilisation of protozoa as a food source.