Acid Intolerant and Ubiquitous Lumbricidae in Selected Habitats in North Wales
1972; Wiley; Volume: 41; Issue: 2 Linguagem: Inglês
10.2307/3476
ISSN1365-2656
Autores Tópico(s)Aquatic Invertebrate Ecology and Behavior
ResumoBornebusch (1930), working on Danish forest soils, distinguished two different ecological groups of earthworms: litter dwellers tolerant of acid conditions and more deeply burrowing species less tolerant of such conditions. Satchell (1955) added to these 'acid tolerant' and 'acid intolerant' groups, a third, of 'ubiquitous' species, found in both acid and neutral soils. The exact nature of the relationship between earthworm distribution and pH is not clear. Many factors, including soil base status, and flora, are associated with acidity. Of particular interest is soil calcium. The family Lumbricidae is characterized by the presence of complex calciferous glands, organs which (in some species at least) secrete calcium carbonate into the oesophageal lumen. In this way excess calcium absorbed from the diet may be excreted (Darwin 1881). It has also been suggested (Laverack 1963) that the glands may facilitate the regulation of acid-base balance by eliminating carbonate from the body. In either case, calcium will play an important r6le in metabolism. It was clearly of interest therefore to examine the distribution and abundance of Lumbricidae over a wide range of soil types, in relation to soil pH, calcium levels in soil and vegetation or litter, etc. This paper describes two such surveys, carried out in an area of North Wales.
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