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RENERGI-Fremtidens rene energisystemer

Can nuisance growth of the aquatic macrophyte Juncus bulbosus be related to elevated nitrogen deposition as well as hydropower regulations?

Awarded: NOK 2.3 mill.

The hydroelectric power industry has thus far been strongly linked to the problem with mass development of the aquatic macrophyte Juncus bulbosus in regulated freshwaters, although other factors like climate variability, acid rain and liming may also cont ribute to the expansion of this species. In southern Norway, there is also a remarkable similarity between the deposition pattern of atmospheric nitrogen and the regional distribution of massive J. bulbosus growth. We hypothesise that nuisance growth can be governed by the skewed stoichiometry (element ratios) of nitrogen (N) relative to carbon (C) and phosphorus (P). On this basis, we propose a four-year research project with the main objective to explore possible links between mass occurrence of J. bulb osus and regional patterns in the stoichiometry of C, N and P in surface waters, relative to impacts from other environmental gradients and flow-regime regulations. The project includes a synoptic survey of 150 lakes, detailed field investigations in a sm aller subset of natural lakes and regulated/non-regulated streams, and growth experiments under controlled laboratory conditions. By means of thorough statistical treatment of all the results obtained from these activities we should be in a good position to generate new knowledge about the factors governing mass development of J. bulbosus.

Funding scheme:

RENERGI-Fremtidens rene energisystemer