Introduced slugs and indigenous caterpillars as facilitators of carbon and nutrient mineralisation on a sub-Antarctic island

• Published in: Soil biology & biochemistry Vol. 39; no. 2; pp. 709 - 713
• Main Author: Smith, V.R.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.2007; New York, NY Elsevier Science
• Subjects: Agronomy. Soil science and plant productions; Alien biota; Biochemistry and biology; biogeochemical cycles; Biological and medical sciences; C:N ratio; calcium; carbon; Carbon mineralisation; carbon nitrogen ratio; Chemical, physicochemical, biochemical and biological properties; Deroceras; Deroceras panormitanum; ecological function; Fundamental and applied biological sciences. Psychology; introduced species; larvae; Litter respiration; macroinvertebrates; magnesium; Microcosm; mineralization; Moth larva; moths; nitrogen; Nutrient cycling; Nutrient mineralisation; Organic matter; Physics, chemistry, biochemistry and biology of agricultural and forest soils; plant litter; potassium; Pringelophaga marioni; Slug; slugs; Soil fauna; soil invertebrates; Soil macroinvertebrate; soil nutrients; Soil science; Sub-Antarctic; Zoology (interactions between soil fauna and agricultural or forest soils); Antarctic region; Antarctic Islands; Moth larva; C:N ratio; Soil fauna; Nutrient cycling; Litter respiration; Soil macroinvertebrate; Sub-Antarctic; Microcosm; Alien biota; Slug; Carbon mineralisation; Nutrient mineralisation; Insecta; Gastropoda; Inorganic element; Limacidae; Pulmonata; Mineralization; Autochthonous; Translocation; Litter; Fauna; Biogeochemical cycle; Subpolar zone; Carbon; Carbon nitrogen ratio; Soils; Deroceras; Larva; Macrofauna; Arthropoda; Lepidoptera; Nutrient; Mollusca; Invertebrata; Respiration
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/j.soilbio.2006.09.026

Indigenous soil macroinvertebrates (moth larvae, weevil larvae, earthworms) are cardinal agents of nutrient release from litter on sub-Antarctic Marion Island (47°S, 38°′E). Their populations are threatened through predation by introduced house mice, which do not prey on an introduced slug Deroceras panormitanum. A microcosm study was carried out to explore whether slugs affect rates of carbon and inorganic nutrient mineralisation from plant litter differently to an indigenous caterpillar (larva of a flightless moth Pringelophaga marioni). Caterpillars stimulated N, Ca, Mg and K mineralisation from plant litter two to five times more than slugs did, whereas the two invertebrate types stimulated C and P mineralisation to the same degree. Consequently, ratios of C:N and N:P released from the litter were different for slugs and caterpillars. Such differences might affect peat nutrient quality and ultimately the peat accumulation-decomposition balance, an important driver of ecological succession. This suggests that slugs cannot simply replace caterpillars without consequences for ecosystem structure and functioning on the island.