Summary
The indirect contribution terrestrial isopods make to decomposition processes by stimulating microbial activites has been quantified in laboratory experiments. The extent to which microbial metabolism is enhanced as a result of the passage of Betula pendula leaf litter through the alimentary system of isopods was measured for both freshly fallen and decayed leaves. Faeces derived from 1 g freshly fallen litter lost 75 mg g-1 D.W. more than did intact leaves, as a result of enhanced microbial metabolism. Faeces derived from 1 g of previously decayed leaves, which were shown to be the preferred food of isopods, lost only 17.5 mg g-1 D.W. more than intact decaying leaves. The isopod's direct contribution to soil metabolism was calculated to be 151 mg and 138 mg g-1 litter ingested when fed on freshly fallen and decayed leaves respectively. It is concluded that the physical and chemical changes in the leaf substrate which result from fragmentation and digestion by isopods do not necessarily accelerate the subsequent decomposition of the litter very significantly. Fungal propagule density was 3.2x and 3.6x higher in faeces derived from freshly fallen and decayed leaves respectively than in the intact litter. Numbers of viable bacteria were correspondingly 126x and 34x higher in faeces than in the freshly fallen and the decayed leaves. Levels of microbial inhibitors were lower in the faeces than in the leaves but levels of free amino acids stayed higher for longer in the faeces than they did in intact litter. In the field the physical removal of litter by the soil macrofauna from surface to deeper and moister microsites may be the most important indirect contribution that they make to decomposition processes.
Similar content being viewed by others
References
Bocock KL (1963) The digestion and asimilation of food by Gomeris. In: Doeksen J, Van der Drift J (eds) Soil organisms. North Holland, Amsterdam, pp 85–91
Coughtrey PJ, Jones CRH, Martin MH, Shales SW (1979) Litter accumulation in woodlands contaminated by Pb, Zn, Cd, and Cu. Oecologia (Berlin) 39:51–60
Edwards CA, Heath GW (1963) The role of soil organisms in the breakdown of leaf materials. In: Doekson J, Van der Drift J (eds) Soil organisms. North Holland, Amsterdam, pp 6–84
Hanlon RDG, Anderson JM (1979) The effects of Collembola grazing on microbial activity in decomposing leaf litter. Oecologia (Berlin) 38:93–99
Hanlon RDG, Anderson JM (1980) The influence of macroarthropod feeding activities on microflora in decomposing oak leaves. Soil Biol Biochem 12:255–261
Hassall M, Rushton SP (1982) The role of copophaphy in the feeding strategies of terrestrial isopods. Oecologia (Berlin) 53:374–381
Hassall M, Rushton SP (1984) Feeding behaviour of terrestrial isopods in relation in plant defences and microbial activity. In: Sutton SL, Holdich D (eds) The biology of terrestrial isopods. Symp Zool Soc Lond 53:487–505
Hassall M, Sutton SL (1978) The role of isopods as decomposers in a dune grassland ecosystem. Sci Proc R Dublin Soc A6:117–127
Heal OW, MacLean SF Jr (1976) Comparative productivity in ecosystems — secondary productivity. In: van Dobben WH, Lowe-McConnell RH (eds) Unifying concepts in ecology. Junk, The Hague, pp 89–108
Ineson P, Anderson JM (1985) Aerobically isolated bacteria associated with the gut and faeces of the litter feeding macroarthropods Oniscus asellus and Glomeris marginata. Soil Biol Biochem 17:843–849
Macfadyen A (1968) The animal habitat of soil bacteria. In: Gray TRG, Parkinson D (eds) The ecology of soil bacteria. Liverpool University Press, Liverpool
Macfadyen A (1971) The soil and its total metabolism. In: Phillipson J (ed) Methods of study in quantitative soil ecology: population production and energy flow. I.B.P. Handbook 18. Blackwell, Oxford, pp 1–18
McBrayer JJ (1973) Exploitation of deciduous leaf litter by Apheloria montana (Diplopoda: Eurydesmidae). Pedobiologia 13:90–98
Mitchell MJ, Parkinson D (1976) Fungal feeding of orabatid mites (Acari: Cryptostigmata) in an aspen woodland soil. Ecology 57:302–312
Nicholson PB, Bocock KL, Heal OW (1966) Studies on the decomposition of the faecal pellets of a millepede (Glomeris marginata (Villers)). J Ecol 54:755–766
Parkinson D, Visser S, Whittaker JB (1979) Effects of collembolan grazing on fungal colonization of leaf litter. Soil Biol Biochem 11:529–535
Persson T, Booth E, Clarholm M, Lundkvist H, Soderstrom BE, Sohlenius B (1980) Trophic structure, biomass dynamics carbon metabolism of soil organisms in a Scots Pine forest. In: Persson T (ed) Structure and function of northern coniferous forests — an ecosystem study. Ecol Bull (Stockholm) 32:419–459
Reichle E (1977) The role of soil invertebrates in nutrient cycling. In: Lohm U, Persson T (eds) Soil organisms as components of ecosystems. Ecol Bull (Stockholm), vol 25. Proceedings of the VI International Colloquium of Soil Zoology, pp 145–156
Satchell JE (1974) Introduction. Litter-interface of animate/inanimate matter. In: Dickenson CH, Pugh GJF (eds) Biology of plant litter decomposition, vol 1. Academic Press, London, pp 13–44
Spiro RG (1966) Analysis of sugars found in glycoproteins. In: Newfeld EF, Ginsburg V (eds) Methods in enzymology, vol 8. Complex carbohydrates. Academic Press, New York, pp 3–26
Turner JG, Taha RR (1984) Contribution of tabtoxin to the pathogenicity of Pseudomonsas syringae p.v. tabaci. Physiol Plant Pathol 25:55–69
Van der Drift J, Witkamp M (1960) The significance of the breakdown of oak litter by Enoicyla pusilla. Beum Arch neerl Zeeol 13:486–492
Visser S (1986) The role of the soil invertebrates in determining the composition of soil microbial communities. In: Fitter AH (ed) Ecological interactions in the soil environment. Plants, microbes and animals. Blackwell, Oxford
Webb DP (1977) Regulation of deciduous forest litter decomposition by soil arthropod faeces. In: Mattson WJ (ed) The role of arthropods in forest ecosystems: Springer, Berlin Heidelberg New York, pp 57–69
Witkamp M, Crossley DA Jr (1966) The role of arthropods and microflora in breakdown of white oak litter. Pedobiologia 6:293–303
Yemm EW, Cocking EC (1955) The determination of amino acids with ninhydrin. Analyst 80:209–213
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hassall, M., Turner, J.G. & Rands, M.R.W. Effects of terrestrial isopods on the decomposition of woodland leaf litter. Oecologia 72, 597–604 (1987). https://doi.org/10.1007/BF00378988
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00378988