Naughty lemmings upset global warming beliefs

PARIS, November 18, 2011 (AFP) – Really, it’s enough to drive a climate scientist over the edge. In past years, satellite images have shown a perceptible growth in grasses and shrubs in parts of the Arctic, a phenomenon pinned on global warming.

But part of the greening could come from lemmings, surprised researchers have found.

University of Texas scientists counted plant cover and biomass in a huge area in coastal Alaska where brown lemmings (Lemmus trimucronatus) have been monitored for more than 50 years in a project to understand their boom-and-bust population cycles.

On small plots that had been fenced off to exclude the lemmings, certain plant types called lichens and bryophytes had increased, the researchers found.

But where the lemmings scampered unhampered, there was an increase in grass and sedge — curiously, the very same plants that the hamster-like herbivores feed on.

The reason for this is unclear. Urine and faeces from the lemmings could be acting as a fertiliser, helping the plants to grow, the researchers suggests.

Alternatively, the rodents could be