Invertebrate macrofauna of a temporary pond in central Italy: Composition, community parameters and temporal succession

The macroinvertebrate fauna of a temporary pond located in a natural reserve near Rome was studied in 1989-1990. Sixteen samples were collected from the pond filling until its drying (about every 15-30 days). A total of 15,000 individuals belonging to 86 taxa (most at species level) was collected during the study. 67 taxa belonged to Insecta (mostly to Coleoptera and Diptera) and 19 to other zoological groups, 6 of which were recorded for the first time in temporary waters. Oligochaetes and dipterans were dominant in the community. The fauna exhibited a remarkable richness and a great turnover of species. The number of taxa was low (9) after the pond was filled (September), increased until a maximum (51) in May and then regularly declined (20) until few days before the pool dried up (early August). This parameter correlated positively with pH values, pond area and wet phase duration. The feeding guilds were represented mostly by detritivores and predators, while the habit organization was dominated by burrowers. The direct relationships between taxonomic diversity and both trophic and habit diversities suggest a good partitioning of food and space resources among taxa. The macrofauna belongs primarily to Group 1 and 2, and secondarily to Group 4 of WIGGINS et al. (1980) classification. The temporal succession of the pond life indicated the existence of three phases, denoted as ''filling'', ''aquatic'' and ''drying'' phases, each characterized by distinctive environmental conditions and faunal groups. There was a high faunal similarity between the first and the last phases due to the great simplicity of the community. The intermediate phase can also include three sub-phases according to the season. The results were compared with data from the few intensive studies on temporary ponds carried out in other countries.