The Deer Balancing Act
Posted: January 21, 2010
21 , 2010- For Immediate Release
Contact: Allyson Muth, Phone: 814-865-3208, E-mail: firstname.lastname@example.org
The Deer Balancing Act
Written by David R. Jackson, Phone: 814-355-4897, email@example.com
Wildlife biologists often speak about "balancing" the deer herd. What does this mean? How many of us really know just exactly what it is they are trying to accomplish, how to go about it, or how to know when we have gotten there? Penn State Cooperative Extension is offering several programs this spring on deer and habitat management -- balancing the herd.
Deer populations larger than the habitat can support pose serious problems for homeowners, agricultural producers, woodland owners, and the public. Safety is one issue affecting many people - from Lyme disease to deer-vehicle collisions. A recent Maryland survey found that 1 out of 6 citizens knows someone who hit a deer with a car. Deer browsing reduces farm crop yields, damages landscape plantings, and reduces forest plant diversity. Managing deer populations so they are in balance with the available habitat is essential.
Research has repeatedly documented deer impacts on tree regeneration and forest herbaceous plant diversity. The ability of a forest to support deer is a function of both deer density and forage availability. By selectively browsing preferred palatable plants, deer influence tree seedling numbers, species composition, and seedling height growth. Because deer are free to move, it is important to consider their management at a landscape level and to understand how concentrated preferential feeding can shift plant communities. As deer feed on one species, another species that is not preferred can become increasingly common. Research findings indicate that when deer numbers exceed what the land is capable of supporting, deer can severely impact the forest's ability to regenerate itself following natural or man-made disturbances.
Landscape level forage
availability relates directly to the ability to support a healthy deer
population. When deer populations are out of balance with available habitat,
preferred forage species decline and subsequent foraging is even more
detrimental to preferred plant species. Preferred plants continue to decline
in abundance and may even be locally eliminated from the landscape. In
regions where over-browsing for decades has severely depleted food species,
even very few deer have major impact and the habitat can only support
very few animals. In landscapes with little preferred forage, deer numbers
in balance with available habitat must be kept low. To sustainably increase
the number of healthy deer the habitat can support, landscape forage availability
must increase. It is possible to increase desirable forage through management
activities such as controlling undesirable vegetation and harvesting trees.
When deer numbers are out of balance with their habitat, look for obvious browse lines, evidence of severe browsing on non-preferred species such as American beech, striped maple, and black cherry, and forest understories dominated by species deer avoid (e.g., hayscented fern, striped maple, American beech, hophornbeam, mountain laurel, blueberry, spicebush). Across Pennsylvania it is relatively easy to recognize areas where the deer-habitat balance has been upset for years: non preferred plant species, such as hayscented fern, cover the forest floor. Many Pennsylvanians have never seen a healthy forest understory. Can these habitats recover over time? How do we move them from undesirable species to create better deer habitat? What kinds of management decisions will lead to the best solutions? Resource managers have some of the knowledge and tools necessary to improve conditions, but sometimes the answers are evasive.
Web seminars and hands-on workshops offered this spring by Penn State Educators and partners will answer some of your questions. The first webinar entitled "Regenerating Hardwood Forests; Managing Competition, Deer, and Light," is on February 9 at noon and 7 p.m. The second webinar, entitled "Deer Habitat Management," is on March 9 at noon and 7 p.m. For webinar details or to register to participate, visit: http://rnrext.cas.psu.edu/PaForestWeb.html.
Penn State will also offer several hands-on workshops entitled "Deer Density and Carrying Capacity Workshops." These workshops are open to landowners, hunters, and anyone interested in learning more about deer and their habitat. During the session participants learn how to evaluate a given habitat, how its condition relates to deer biology, density, and carrying capacity. For a listing of dates and locations for these workshops, visit the Renewable Natural Resources Extension webpage at: http://rnrext.cas.psu.edu, and click on the "Calendar" Quick Link on the right hand side of the page.
The Pennsylvania Forest Stewardship Program provides publications on a variety of topics related to woodland management for private landowners. For a list of free publications, call 1-800-235-WISE (toll-free), send e-mail to firstname.lastname@example.org , or write to: Forest Stewardship Program, Forest Resources Extension, The Pennsylvania State University, 416 Forest Resources Building, University Park, PA 16802. The Pennsylvania Bureau of Forestry and USDA Forest Service, in partnership with the Penn State's Forest Resources Extension, sponsor the Forest Stewardship Program in Pennsylvania.
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