Indicadores ecológicos de algunos ecosistemas acuáticos del Bajo Guadalquivir (SW; España): odonatos heterópteros y coleópteros acuáticos

Abstract

ECOLOGICAL INDICATORS OF SOME AQUATIC ECOSYSTEMS OF "BAJO GUADALQUIVIR" (S.W. SPAIN): ODONATA AND AQUATIC HETEROPTERA ANO COLEOPTERA Toe indicator value of 56 populations of Odonata and aquatic Coleoptera and Heteroptera was detennined from aquatic ecosystems of low Guadalquivir river by a statistical procedure (Binary Discriminant Analysis), as a part of a general ecological study.In general, permanent sites on sand substrate are used as temporary residences by a great number of migratory species of Coleoptera and few species of Heteroptera. Permanent waters on clay, within the endorheic area are properly used to reside and to breed mainly by Heteroptera and Odonata. Temporary waters of salt marshes support breeding Odonata, Coleoptera and Heteroptera specially adapted to extreme fluctuations and dry periods which are typical of these ecosystems.

Limnological comparison of two peridunar ponds in the Doñana National Park (Spain)

“…Previous physical and chemical data (Montes et al, 1982;Furest & Toja, 1981) indicated a progressive increase in calcium and pH values. Changes in phytoplanktonic communities can also be observed: the dominant species are different from those quoted by other researchers (Margalef, 1976); and Spirulina platensis, a species typical of alkaline waters (Margalef, 1983), not mentioned before, now appears among the phytoplankton.…”

“…From a limnological point of view, there have been previous studies on water chemistry (Margalef, 1976;Furest 8c Toja, 1981Montes et al, 1982), phytoand zooplankton (Bigot 8c Marazanoff, 1965;Margalef, 1976;Armengol, 1976;Furest 8c Toja, 1984, 1987, which showed differences be tween the two ponds in spite of their proximity. Nevertheless these studies, being sporadic and short-termed, have not allowed us to understand how long term fluctuations affect the limnological features of both ponds.…”