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THE MORE DIATOMS IN SPRING, THE LESS CYANOBACTERIA IN SUMMER: IMPLICATIONS FOR ENVIRONMENTAL MANAGEMENT AND EUTROPHICATION CONTROL

Vladimir Krivtsov

I would like to draw the attention of the cyanobactrerial research community to the recent findings (Krivtsov, 2000) related to the regulation of nasty summer blooms by promoting diatoms in spring (Krivtsov et al. 1999, 2000a), which provides a theoretical basis for a new measure of eutrophication control. This phenomenon is a particular case of a more general pattern outlined below.

Consecutive stages of ecological succession are often dominated by different species and limited by different resources. If the resource limiting at the later stage is also essential for growth of the species dominant at the earlier stage, the two successive dominants may have a negative correlation. This provides a possibility of manipulating community structure at the later stage by causing changes at the earlier stage (Krivtsov et al., 2000b).

Both empirical analysis and modelling showed an inverse relationship between spring (mainly limited by Si and sedimentation) and summer (mainly limited by N and/or P) primary producers in certain temperate lakes. Hence the summer dominance of cyanobacteria could be lessened by promoting the spring diatoms.

To find out more about the above mentioned issues email the author to request the papers.

References

Krivtsov V. (2000). Environmental studies on the Rostherne Mere ecosystem, combining traditional methods with scanning electron microscopy X-ray microanalysis and mathematical modelling. PhD Thesis. The University of Manchester.

Krivtsov, V., Bellinger, E., Sigee, D. and Corliss, J. (1999). Examination of the phytoplankton of Rostherne Mere by using a simulation mathematical model. Hydrobiologia, 414, 71 - 76.

Krivtsov,V., Bellinger, E., Sigee, D. and Corliss, J. (2000a). Interrelations between Si and P biogeochemical cycles - a new approach to the solution of the eutrophication problem. Hydrological Processes, 14/2, 281 - 294.

Krivtsov, V., Corliss, J., Bellinger, E., Sigee, D. (2000b). Indirect Regulation Rule for Consecutive Stages of Ecological Succession. Ecological Modelling (in Press).