Photoautotrophic community changes in Lagunillo del Tejo (Spain) in response to lake level fluctuation: two centuries of sedimentary pigment records.

摘要: Lagunillo del Tejo is a small doline lake in karstic region of the Iberian Ranges (central-eastern Spain) that undergoes significant level fluctuation response to changing aquifer influxes. In order assess changes primary producer community over last two centuries and elucidate whether these were conditioned by climatic variability, photosynthetic pigments their derivatives extracted from sediments data analysed using multivariate statistical techniques. Quantitative variations total pigment concentrations through sedimentary sequence are considered result sedimentation rate, largely due fluctuation. Rapid lowering results an increase detritic mineral matter eroded sides lake, which accumulates sediment dilutes organic content corresponding layers. On other hand, shifts relative abundances different suggest development communities: (i) planktonic, comprising cyanobacteria, chlorophytes, cryptophytes purple sulfur bacteria (ii) producers related littoral environment, mostly submerged macrophytes. These communities showed alternating importance centuries, as biotic during wet dry periods, respectively.