SEASONAL-CHANGES IN THE INVERTEBRATE COMMUNITY OF SMALL SHALLOW EPHEMERAL PANS AT BAIN VLEI, SOUTH-AFRICA

Changes in invertebrate population numbers and composition were monito red in six small shallow ephemeral pans during four consecutive inunda tions of spring, summer and autumn 1988/1989. The community was genera lly characterized by crustaceans and was invaded by insect larvae in s ummer. Community changes and succession were prominent in spring but l ess so in summer and autumn. Large pans supported more species than sm all pans. During longer inundation there was less difference between t he initial and the final population composition than during shorter in undation, although the total population density did not increase signi ficantly. This indicated that population composition stabilized as inu ndation lengthened. Population changes of six representative taxa were not correlated to changes in the physical and chemical characteristic s of the water.