Naughty lemmings upset global warming beliefs

Ishara S. Kodikara | AFP | Getty Images Sri Lanka Prime Minister Ranil Wickremesinghe, center, speaks to supporters at the prime minister's official residence in Colombo on December 16, 2018, after he was reappointed as prime minister by Sri Lanka's president, the same man who fired him from the job nearly two months ago.

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