The science of yellow snow: White-tailed deer may be ruining their own winter havens

Jun 04, 2013 by Jennifer Donovan
The science of yellow snow: White-tailed deer may be ruining their own winter havens
Deer like to gather under the protection of evergreens like northern white cedar in the winter .

(Phys.org) —New research from wildlife ecologists at Michigan Technological University indicates that white-tailed deer may be making the soil in their preferred winter homes unfit to grow the very trees that protect them there.

Bryan Murray, a PhD candidate at Michigan Tech, and two faculty members, Professor Christopher Webster and Assistant Professor Joseph Bump, studied the effects on soil of the nitrogen-rich waste that white-tailed leave among stands of eastern hemlock, which are among their favorite wintering grounds in the harsh, snowy climate of northern Michigan. Webster and Bump are on the faculty of Michigan Tech's School of and Environmental Science.

They compared eastern hemlock stands where deer congregated to stands where deer were fenced out and found a strong relationship between the amount of from the deer's waste products and the kinds of plants that flourished there. Their research results were reported online in the journal Ecology, published by the .

"Altering the nitrogen availability in a hemlock stand may affect its ability to continue functioning as a deeryard by changing the types of plants that grow there," said Murray, first author on the journal article titled "Broadening the ecological context of ungulate-ecosystem interactions: the importance of space, , and nitrogen." For example, he said, "high inputs of nitrogen may hasten the transition of hemlock stands to hardwood species that provide scant winter cover."

During cold northern winters, deer seek out stands of evergreens with dense crowns, such as eastern hemlock, northern white cedar and balsam fir. Such stands of trees are known as "deeryards." They are thought to provide refuge from deep snow and blustery winds and to help deer hide from predators, Murray explained.

Deer instinctively seek deeryards, but their choice of location is knowledge passed from mother to fawn. Thus deeryards that are traditional favorites can harbor 100 deer or more per square mile, creating hotspots of high-nitrogen-content waste.

Long ago, before logging enabled the white-tailed deer to move further and further north and before the deer population explosion more recently experienced, the ecosystem stayed balanced because there were plenty of deeryards and fewer deer. Now more deer are crowding into less winter cover, shifting the dynamic balance of nature.

The Michigan Tech research demonstrates that the relationship of deer to their habitat is more complex than just the plants they eat, Webster said. "Our hope is that by better understanding the links between habitat use and spatial patterning of resources and plants in survivng hemlock stands we can identify sustainable management strategies for this critical resource."

"It was fascinating to discover such complex interactions, which have implications for sustainable management, in a seemingly simple ecosystem," Murray added.

Explore further: Japan's new whaling plan will prove hunt is science: negotiator

More information: www.esajournals.org/doi/abs/10.1890/12-1582.1

add to favorites email to friend print save as pdf

Related Stories

Loss of eastern hemlock will affect forest water use

May 09, 2013

The loss of eastern hemlock from forests in the Southern Appalachian region of the United States could permanently change the area's hydrologic cycle, reports a new study by U.S. Forest Service scientists at the Coweeta Hydrologic ...

Maine weather wreaking havoc on deer

Mar 30, 2008

Deer living in Maine and other portions of New England are likely battling starvation because of the region's tough winter, biologists say.

Researchers predict locations for deer vs. car collisions

Jun 30, 2011

University of Alberta researchers have produced a map of Edmonton predicting the most likely locations where vehicles will collide with deer. These collisions can be fatal for drivers and their passengers. The hot spots for ...

Recommended for you

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.