The effects of ozone depletion and the burning of fossil fuels mean that plants are likely to be exposed to increasing atmospheric carbon dioxide (CO₂) and ultraviolet-B radiation, especially in polar regions.

It had been thought that the soil microbes associated with such plant communities would be strongly affected by increasing CO₂, at least indirectly, but relatively insulated from the effects of UV-B radiation.

But a five-year study by David Johnson of the University of Sheffield, United Kingdom, and colleagues suggests otherwise

The researchers — whose results are published in the 7 March issue of Nature — studied of a patch of subarctic heath in Swedish Lapland. They found that increases in UV-B radiation — with or without raised atmospheric CO₂ — significantly reduce the amount of nitrogen that soil bacteria hold.

Reference: Nature 416, 82 (2002)

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