Respiration rates and population metabolism of woodland snails

Experiments were done to measure the respiration rates of twenty species of terrestrial snail. Acclimatization phenomena were sought in two species, Discus rotundatus and Hygromia striolata, but not detected. The Q _10s between 5 and 15° C for the twenty species varied between 1.20 and 4.27, with a mean Q ₁₀ of 2.21. Q ₁₀ was higher in larger snail species. There was an increase in respiration with body weight for those species which grew to a large size, but the trend was not detectable in species with small adult weight. A double log plot of mean respiration rate of each species against the mean weight of each species gave a linear relationship.Mean monthly leaf litter temperature was measured in a beech woodland site in Wytham Woods, Berkshire. Litter temperature, in combination with snail population data and size class distribution, was used to calculate population metabolism of the snails on the site. Annual population metabolism amounted to 7.0934 kcals/m²/annum. The estimated annual production was 4.4386 kcals/m². The P/R ratios varied between 0.143 and 1.861, P/B ratios varying from 1.0 to 34.3. From the data it is suggested that respiration alone will not give a good measure of the importance of different species in litter breakdown.