October 2008

The DNR communications team works with agency experts to develop the weekly questions and provide the answers. This feature addresses current DNR issues, interesting topics, or the most frequently asked questions from around Minnesota.






Why should we plant native trees and other vegetation in an urban area? What sort of benefits do they offer?

One major benefit to planting native species in urban areas is that they are adapted to the local climate and soil conditions. They generally thrive with very little attention and can survive extreme weather conditions very well. Native plants are also important to wildlife because they provide food and shelter. Because native plants are found throughout Minnesota, they’re a better alternative than non-native species, which can cause ecological damage to our natural environments. Some non-natives, such as buckthorn, are known to invade our prairies, forests and water bodies, spread quickly and crowd out native plants. So when we see a native oak or dogwood growing in an urban setting we maintain our connection to the natural world and protect Minnesota’s natural resources.

- Welby Smith, DNR state botanist


On occasion, an eerie green glow can be seen illuminating from the forest floor. Is there something causing this or is it an unexplained Halloween phenomenon?

This phenomenon, called “foxfire,” is a blue-green glow given off by the mycelia (threadlike strands) of certain fungi that grow in rotting wood. Armillaria, a root- and trunk-rotting fungus common in Minnesota, is one such organism that can emit a faint, blue-green light seen at night. It grows on hundreds of species of trees, shrubs, vines and forbs found in forests, along roadsides, and in cultivated areas.

Bioluminescence, the emission of light from living organisms, is most likely to occur when decomposing wood is damp and when the temperature is in the high 70s. If you want to see foxfire, go for a hike in the woods after dark on a cloudy or moonless night in late summer or early fall. If you kick some decayed and softened stumps, you may also have a shoe that glows in the dark!

- Jana Albers, DNR forest health specialist


A telltale sign that winter is approaching is the ongoing wildlife activity. Although birds migrate to warmer climates, many wildlife species stay put, including the creepy, crawly, and slithery critters. What do reptiles and amphibians do to prepare for winter?

Since Minnesota's 50 species of amphibians and reptiles can't migrate south to escape the wrath of winter, these cold-blooded animals search for sites in the fall that meet their over-wintering needs. Strategies for surviving the inevitable chill are interesting and varied. Some seek safety underground, traveling deep into rock crevices or burrows to escape the frost line. Others take refuge in aquatic habitats, remaining submerged throughout the winter. Wood Frogs and members of the treefrog family are truly hardcore, nestling themselves under a thin blanket of leaves on the forest floor, freezing solid. They protect vital organs by creating their own antifreeze. These frozen frogs do not breathe or have a pulse, yet recover quickly when spring returns. Amphibians and reptiles typically settle in to their winter home by late October, however global climate change could alter seasonal patterns in animals whose activities are closely linked to temperature.

- Carol Hall - DNR herpetologist


DNR Question of the Week Archive