摘要

Although land snail communities could be a good indicator of soil quality and landscape structure impact, they are seldom analysed in an urban context, probably because of the lack of interest in this ecosystem and because no fast and reliable method of inter-site comparison seems to exist. The classical method of removing large quantities of soil leads to degradations unsuitable in urban gardens and involves time-consuming sorting. For the purpose of ecological comparisons, we analysed different methods to assess land snail communities in urban parks in order to set up a simplified strategy. Snail communities were sampled in three parks within the city of Paris (France) using (1) quadrat method (litter and soil removed over a given area, snails sorted later in the laboratory), (2) visual search in situ (hand-picking snails in the leaf litter), (3) wooden boards placed on the ground and regularly checked, and (4) pitfall traps, usually used for insect sampling. Our results suggest that the wooden board and pitfall trap did not yield enough data to determine community structure and that visual search was not sufficient to sample all dominant species, especially the smallest ones. In order to allow for replication of samples, we suggest a mixed strategy suitable for ecological comparisons, combining visual searches of five 0.5 m(2) areas (15 min for each area) and litter and soil sampling on two 0.0625 m(2) quadrats.

  • 出版日期2011-5