Szukana fraza: [Abstrakt = "Analyses have been carried out of the rate of phosphorus and nitrogen regeneration by the zooplankton of 42 lakes representing a trophic and morphometric gradient. For unpolluted lakes a high growth of the rate of P and N regeneration has been found, as well as a reduction of the turnover time of phosphorus and of the value of the N \: P ratio in the products of regeneration following an increase in the pool of total phosphorus. The importance is discussed of changes in the internal cycles of P and N, connected with changes in the trophical conditions of the lakes, to the consequences of the process of eutrophication."]