From bad to benefactor. (Clippings).

For many years forest rangers waged a war against dwarf mistletoe (Arceuthobium sp.), a parasitic plant that attacks the towering evergreens of the American West. (Dwarf mistletoe is different from the leafy kind that lovers hang out under at Christmas.) Rangers routinely cut dawn or burned infected trees, so the pesky plant wouldn't spread. But recently, scientists have discovered that dozens of forest creatures depend on mistletoe for food and shelter. So now forestry policies are changing.

Most plants make their own food, hut dwarf mistletoe is a thief. It jams root-like sinkers into delicate tree tissue and steals food and water from its helpless host. The wounded tree responds by sprouting a compact bundle of slender twigs. After a few years of growth, the tangled mass, called a "witches' broom," resembles the business end of an old-fashioned broom.

There are about 40 species of dwarf mistletoe in the genus Arceuthobium, and each species attacks a specific species of tree. Eventually, dwarf mistletoe plants steal enough water, minerals, and nutrients to kill the ponderosa and lodgepole pines, Douglas-firs, western larches, and western hemlocks they attack. In the meantime, the parasites--and the neighboring wildlife--live well.

As mistletoe grows and reproduces, the shoots, flowers, and berries provide food for a variety of creatures. From the time a thicket hairstreak caterpillar hatches to the time it transforms into a butterfly, it eats nothing but mistletoe shoots. House sparrows, black-capped chickadees, and blue grouse dine on mistletoe berries, while porcupines devour whatever plant parts they can reach. And when tree branches draped with mistletoe fall to the ground, deer and elk enjoy a mistletoe feast.

Meanwhile, witches' brooms serve as a safe haven for daddy longlegs and pseudoscorpions. They are also prime real estate for red squirrels, bushy-tailed wood rats, northern goshawks, great gray owls, and long-eared owls. These treetop homes offer protection from predators and the weather.

Knowing that so many creatures depend on mistletoe for homes, hiding places, and hunting grounds has changed the way we think about and treat the problematic plant. By allowing dwarf mistletoe to grow and create witches' brooms, we are helping a whole community of living things survive and reproduce.