Effects of artificial liming on land snail populations in a woodland at Ekeröd, Skåne, Sweden


In Sweden, there are several land snails which appeared vulnerable to the effects of acid rain and it was therefore suggested that these would be useful, due to there demand for calcium, for monitoring changes in pH of litter and soil. In this study, as part of a wider project addressing this issue, plots in a forest in southern Sweden were artificially limed to assess effects on snail species and densities.

Study site: The study took place in a 80-100 years old beach Fagus sylvatica forest at Ekeröd, Skåne (Scania), southern Sweden. Litter pH varied from 4.2 to 5.1.

Liming: In 1983, nine of 12 adjacent (10 x 10 m) plots were limed with 2, 5 and 10 tonnes of dolomite lime (containing 12% MgCO3)/ha. Three plots were left as unlimed controls.

Snail sampling: Snail populations were estimated in July 1988 from three samples of 0.1 m² area in one of each level of the limed plots, and one control plot.

Litter analysis: From litter samples, pH was measured in the laboratory and analysed for total calcium, exchangeable calcium, exchangeable phosphorus, exchangeable potassium, total nitrogen, base ion concentration and base saturation.


Ten snail species were recorded, along with five slug species (Arion silvaticus, A.subfuscus, A.ater, Limax tenellus and L.marginatus; observed but not counted). Snail species recorded and their population densities are summarized in Table 1 (attached)

Five snail species were only recorded in limed plots. All species found in unlimed plots had higher population densities in limed plots (except Columella aspersa a 2 t/ha) and in general the higher the lime dose the higher the population density. In plots treated with 10t/ha, mean densities increased 4-40 times, depending on the species (5 years after liming).

There were highly significant correlations between snail density and pH, Ca concentration, base cation concentration and base saturation; however, the correlations between nitrogen, phosphorus and potassium were very low.

Conclusions: The results indicate that liming positively affects land snail population densities in this relatively nutrient-poor deciduous forests.

Note: If using or referring to this published study, please read and quote the original paper, this can be viewed at:


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