New Research Published - Excessive deer populations facilitate garlic mustard invasion

Just last week we posted on this blog about a recent article about deer overabundance impacting aboveground vegetation and seed bank and how they influences the forest community.  (See original post HERE).

Now, new research has been published that further investigates the specific relationship between deer populations and invasion by garlic mustard, Alliaria petiolata.  In the latest issue of Proceedings of the National Academy of Sciences (vol. 111, no.12), Kalisz et. al  published an article titled "In a long-term experimental demography study, excluding ungulates reversed invader's explosive population growth rate and restored natives."  In this article, the authors argue that successful garlic mustard invasion is dependent upon high deer populations.

From a release about the article on Science Daily -
(http://www.sciencedaily.com/releases/2014/03/140320111932.htm)

To study the effect of rampant deer on trillium and garlic mustard populations, the researchers established multiple 196-square-meter plots in the forest. Half were fenced to exclude deer. Years of observation and hours of statistical analysis later, the team found that in plots where deer were excluded, the trillium population is increasing, and the garlic mustard population is trending toward zero.  "This demonstrates that the high population growth rate of the invader is caused by the high abundance of deer," says Susan Kalisz, professor of evolutionary ecology in the University of Pittsburgh's Department of Biological Sciences and principal investigator of the study. This effect is reversible with deer exclusion.

The full research article can be found here:
http://www.pnas.org/content/111/12/4501

Forest Health Programs of the U.S. Forest Service, Department of Agriculture, Applying an Exotic Plant Strike Team Strategy to Improve Forest Health in Northwest Illinois

Jeff Horn, Director of Land Stewardship
Jo Daviess Conservation Foundation

Invasive species cost the United States more than $120 billion in damages every year. Invasive plants species are plants brought here from elsewhere in the world that do not have natural enemies in the areas they are invading. This allows invasive plant species to spread rapidly through landscapes. This rapid spread can cause enormous damage to agriculture, fisheries, forestry, and outdoor recreation.


With funding from the USDA Forest Service and the Illinois Department of Natural Resources (IDNR), and in cooperation with Jo Daviess Conservation Foundation (JDCF) and US Fish and Wildlife Service (USFWS), a two-person Strike Team was formed to work year-round on controlling and monitoring invasive plant species in Northwest Illinois. The Nature Conservancy (TNC) helped initiate the setup of this team.



Report available HERE

 In February of 2013 the Northwest Illinois Strike Team (NWST) began controlling and monitoring of invasive plant species in State designated nature preserves, natural areas, and lands adjacent to natural areas in six northwest Illinois counties. The NWST used mechanical methods, prescribed fire, and herbicide application to suppress established invasive weed populations and prevent future populations from establishing. The NWST prevents further spread of invasive weed populations into natural areas by responding early to new infestations. The goals of the NWST include: managing existing invasive species populations, preventing the spread of invasive species to natural areas, and re-establish native plant communities to restore health to these natural areas. Thus far, they have treated over 650 acres of invasive plants in natural areas.

The Jo Daviess Conservation Foundation’s mission is to conserve and enhance natural wildlife habitat, cultural heritage, scenic vistas, and the agricultural character of Jo Daviess County and the surrounding area for future generations. JDCF owns several beautiful and unique preserves all of which are open to the public for hiking, wildlife viewing, and picnicking. For more information, visit their office at 126 N Main Street in Elizabeth, IL, call (815) 858-9100, or find them online at www.jdcf.org.

 

New Research Published - Deer proliferation disrupts a forest's natural growth

An article from DiTommaso et. al was recently published in the Journal PLOS ONE.  This research, titled 'Deer Browsing Delays Succession by Altering Aboveground Vegetation and Belowground Seed Banks' indicates that expanding deer populations can stall the development of forests and promote the growth of invasive plants. 

From a release about the article on Science Daily - (http://www.sciencedaily.com/releases/2014/03/140308095500.htm)

Deer typically prefer to eat native, woody plants and rebuff invasive species. The study showed that when deer consume native plants, the non-native species are left to flourish, dropping seed in the soil.

"It's obvious that the deer are affecting the above-ground species, but it's like an iceberg. There are major effects below the soil surface. We are seeing a divergence of seeds contained within the soil from what should be there," says DiTommaso. "We are not seeing the seeds of woody plants. Instead, we're seeing an escalation of non-native seed and the virtual elimination of woody plant seeds."

See the full research article here:
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0091155

MIPN/OIPC Conference presentations available online

The Midwest Invasive Plant Network and the Ohio Invasive Plant Council jointly organized an invasive plant symposium as part of the Northcentral Weed Science Society meeting inb December.  Many of the presentations given at this symposium are now available on the MIPN website:

http://www.mipn.org/2013Symposium.html

Session topics included:

• New Tools and Technology for Invasive Species Reporting and Information Sharing
• Strategies for Outreach on Invasive Ornamental Plants
• Invasive Plant Management
• Assessing Invasiveness of Invasive Plants
• Asian Bush Honeysuckle: Recent Advances in Research and Control