THE EFFECT OF PHYSICAL AND CHEMICAL PARAMETERS ON THE STRUCTURE AND COMPOSITION OF THE PHYTOPLANKTON COMMUNITY OF LAKE BUDI (IX REGION, CHILE)

摘要: ABSTRACTThe chemical characteristics of the waters Lake Budi (IX Region, Chile), in winter and summer were analysed order to establish seasonal variations determine their influence on various phytoplankton components. On basis results it was possible indicate that parameters found water body under examination vary time space, giving rise different algal communities. The strong salinity communities both study periods appears result principally from sea, resulting intrusion salt during certain year. predominant characteristic indicates a slight reduction quality, due temperature oxygen concentration. Keywords: Budi, salinity, phytoplankton, quality.INTRODUCTIONPhytoplankton constitutes most important primary producer, is fundamental food source for consumers many continental aquatic systems [1-2-3]. However wide spectrum organisms which made up limnological may be encountered each individual system have hindered understanding processes involved population dynamics [4]. In general, has been established determining factors structure lakes relationship exists between physical, biological present [5]. Several studies carried out freshwater environments growth controlled large degree by limitation nutrients [6-7], availability light [8] composition abundance zooplankton [9]. It also determined coastal are subject marine some period year, factor affecting distribution [10-11]. above consequence problems osmotic regulation produced sea-water, [12]. Under natural conditions, respond regular manner environment occur an annual cycle [13-14]. This largely changes physical stability column. As result, varying components lake clear indicator its environmental state. this respect, analysis presence species, biomass, can provide information needed evaluate ecological state lacustrine systems. However, do not only into lakes, but as human interventions body, either directly or through activities basin whole. These influences modifications take form taxa associations composed, taxa, richness diversity associations, other community parameters. Finally, interdependence existing these translate trophic chain productivity [15]. where there Moreover, recent decades considerable intervention basin. two indubitably conditions column lake.As proposed, aim greatest influence, Budi.EXPERIMENTALArea sample collectionLake (38o 52’ S; 73o 18’ W) connected sporadically sea. Different bio-types recognized surroundings: banks, covered with vegetation bare; mud-sand beaches; sediments high content organic material derived plants [16].Based special contribution principal tributaries (Budi, Temo, Allipen, Comue, Bolleco Botapulli), nine sampling stations established: Rio Bolleco, Botapulli, Deume 1, 2 3 (Fig. 1). To account samples taken at times first July 2004, representing winter, second January 2005, reflecting conditions. Two station: surface (20cm) deep (1 m), exception station, shallowness sampling. Chemical Analysis Eight quality study: temperature, pH, solution (OS), biochemical demand (BOD), total suspended solids (TSS), (OSS) nitrates. extracting using Ruttner bottle, duplicate. Consideration given sampling, type container, preservation maximum time-lapse taking [17-18].e-mail: jtapia@utalca.cl