REALLY?

LITTLE ROCK — Should mistletoe always be removed from forests?

A recent Australian study has come up with a surprising new understanding of the evergreen, parasitic plant: While it harms individual trees, its impact on the forest overall is positive.

This is a 180-degree shift in opinion about mistletoe, which has long been considered a detrimental parasite. The image makeover stems from an experiment started in 2004 in a small forest surrounded by farmland in the upper Billabong Creek area of Australia’s New South Wales. David Watson, an ecologist at Charles Sturt University in Albury, New South Wales, removed mistletoe from 17 woodlands and compared them with 11 woodlands where the mistletoe remained and 12 others naturally devoid of the plant.

Three years after the mistletoe vanished, so had more than a third of the bird species, including those that fed on insects. Where mistletoe remained, bird species increased slightly. It was a similar story for some mammals and reptiles, but, in another surprise, particularly for those that fed on insects on the forest floor.

Analysis showed that species of mistletoe plays an important role in moving nutrients around the forest food web. Nonparasitic plants suck nutrients out of their own leaves before they let them fall, sending dry containers to the ground.

But because mistletoe draws water and nutrients from the tree stem or branch it attaches to, it makes the tree drop leaves still full of nutrition. Those fallen leaves feed creatures on the forest floor.