September 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 do trees change color in the fall and what determines if we have a good display on a given year?

Those magnificent colors you see in the fall are actually there all summer, its just you can't see them because of the green chlorophyll in the leaves. As our days get shorter and the temperatures cool down, trees cease green chlorophyll production causing the reds to form, oranges and yellows to show.  Any sugars trapped in the leaf will react with each other in the presence of sunlight - thus the more sun, the more brilliant the red colors. The best weather conditions are the same ones we enjoy in the fall - bright, cool days and chilly but not freezing nights. The slightest change - too hot, too cold, too wet or too dry - can slow the process, or cause trees to lose their leaves before they change color.

Minnesota is fortunate to have many excellent places to view the changing season - from the northern hardwood forests along the North Shore to the prairie regions of the state. To get the latest information on when and where the fall colors are expected to be at their peak, check out the DNRs Web site,

- Linda Radimecky, Fort Snelling State Park naturalist


Technology has improved hunting and fishing. But some pieces of equipment, such as cell phones and two-way radios, can be illegal if misused. What is the state law on the use of such communications devices?

In addition to their blaze orange clothing, guns and other hunting gear, hunters are increasingly becoming technology-savvy. This includes the use of cellular phones and two-way radios. These devices can save lives, help people find lost hunters and even allow hunters to chat with their spouses as they sit around a campfire at night. But just because they’re readily available doesn’t mean they are necessarily legal when used as an aid in hunting or fishing in Minnesota, or any other state. According to Minnesota hunting regulations, it is illegal to use radio communications to aid in the taking of game. For example, hunters cannot communicate the locations of wild game or use the devices while driving animals to other hunters. Conservation officers do occasionally encounter hunters using some form of radio communications to assist others in the taking of game animals, and do write citations for this violation. Additional information about the use of radios while hunting can be found under general hunting information in the Minnesota Hunting and Trapping Regulations Handbook.

- Rich Sprouse, DNR Enforcement Division information officer


It appears to be that time of year for tree diseases to surface. Is there anything homeowners can do to protect their trees from diseases and possible mortality, regardless of tree species?

There are a number of things that homeowners can do on their own to help keep their trees healthy. Since many areas of the state are experiencing some type of drought conditions, a good place to start is watering your trees. The lack of water predisposes trees to insects and pathogens that can only successfully attack drought-stressed trees. So, wherever possible, homeowners should give their trees about one inch of water each week.

In addition to watering, apply organic mulch two- to three-inches deep and spread it out three- to eight-feet from the trunk. This will guard against lawn mower injury and keep the roots moist. Homeowners should also avoid using weed and feed fertilizer products that contain herbicide. While the product makes lawns look good, it does kill tree roots. Picking up and properly disposing of fallen leaves and tree branches can also help prevent the spread of tree diseases now and next spring. For more information, go to DNR’s Web site at

- Jana Albers, DNR forest health specialist


The fall hunting season is upon us. Do resident or non-resident hunters who possess a lifetime Minnesota hunting license need to get a license for the current year?

Every hunter who possesses a lifetime Minnesota hunting license must obtain an annual license at no cost for the current year. This rule also applies to those who have purchased lifetime angling licenses. Those planning to hunting for pheasant, turkey or waterfowl, or fish for trout, must purchase the necessary stamps. Hunters who intend to harvest migratory game birds must also get their HIP (Harvest Information Program) certification. Those planning on taking part in the annual firearms or archery deer hunting seasons must register and receive tags each year and must apply for the antlerless deer permit drawings in areas where the lottery system is still used. All tags must be used in the year issued. Regular deer tags will be issued at no charge to the licensee; however, hunters will be charged for additional management or intensive harvest tags.

- Steve Michaels, ELS program director, Minnesota DNR License Center


DNR Question of the Week Archive