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The Greenland High Arctic is a bare, sparse¹ place. Rather than tall trees, it has tundra²—ground hugging vegetation—and rugged³, Lord-of-the-Rings-style vistas⁴. "Well I don't know, it's not exactly New Zealand, but kind of similar landscape."

Mikko Tiusanen, an ecologist at Helsinki University in Finland. "The winter season is like six, seven months. So everything basically happens during the short summer season." Including the white-yellow bloom of mountain avens, a hardy⁵ arctic shrub⁶. "Even though it's small it can be over 100 yrs old. It's pretty good at surviving harsh conditions." 

Tiusanen and his colleagues set out to census⁷ which of the many local insects visit mountain avens by summer, and help with pollination⁸. So they planted 2100 sticky flower lookalikes, as traps, and identified stuck visitors by their DNA⁹. 

Two-thirds of all local insect species visited. But it was one particular fly, a relative of the humble¹⁰ housefly, that showed up most often in those spots where the tundra shrubs¹¹ had successfully set seed. Meaning more flies appeared to be a good thing for the avens. The study appears in the Proceedings¹² of the Royal Society: B. [Mikko Tiusanen et al, One fly to rule them all—muscid flies are the key pollinators in the Arctic]

Here's the bad news: a 2013 study found that the Arctic flowering season is shortening. The numbers of fly pollinators is down, as is the the number of visits by these fly pollinators. Which could be bad for mountain avens—and beyond. "One could expect that also the other pollinators and flower visitors visiting the mountain avens could get more uncommon¹³ and even become extinct in the long run." Meaning "shoo fly" could spell trouble for the life of the tundra.

—Christopher Intagliata

[The above text is a transcript¹⁴ of this podcast.]