The use of two lumped models for the analysis of consequences of external influences on the Lake Baikal ecosystem

The application of two lumped models to the prediction of the anthropogenic changes in the ecosystem of Lake Baikal is described. The first model is the static size conversion model, describing the changes in the ecosystem caused by a conservative pollutant present in sub-lethal concentrations. The second one is the model of the ecosystem disturbances. It is based on the data of field experiments and describes the interaction of the ecosystem components with the nutrients and phenolic compounds in the under-ice and summer–autumn seasons. The static model has demonstrated the higher sensitivity of top trophic levels to external influences and necessity to take these levels into account during monitoring works. The model of the anthropogenic disturbances of the Lake Baikal ecosystem has shown higher sensitivity of under-ice community than summer one. The possible reasons are discussed. Exergy content is shown to decrease under the action of conservative pollutant and increase after addition of nutrients and phenolic compounds, reflecting the general shifts in ecosystem. The calculations of buffer capacities demonstrated that exergy buffer capacity seems to be more realistic one than biomass buffer capacity.