Snail numbers, biomass and respiratory metabolism in a beech woodland - Wytham Woods, Oxford.

Two methods of extraction were used in the estimation of snail population densities in woodland litter. The time-consuming-Vágvölgyi technique proved to be 6.25 times more efficient than infra-red heat extraction but it was shown that the results obtained by the latter method could be easily corrected to conform with those of the former.Snail density varied with season (Winter, 1,000-1,250 m-2, Summer, 50-600 m-2), the annual mean density being 645 m-2. The annual mean ash-free dry weight biomass was 176 mg m-2 while annual population metabolism equalled 0.8941 O2 (=17.84 kJ m-2 yr-1).Two independent estimates of the energy equivalent of food consumption gave rise to values of 25.37 and 57.98 kJ m-2 yr-1, these respectively account for 0.54 and 1.23% of the known ground litter disappearance of 4,716.58 kJ (=235 g dry wt. m-2 yr-1).