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Beyond Lyme: New Tick-Borne Diseases On The Rise In U.S.

Beyond Lyme: New Tick-Borne Diseases On The Rise In U.S., NPR, March 11, 2017In the Midwest, you can find Heartland virus, a new Lyme-like disease and Bourbon virus — which is thought to be spread by ticks but hasn’t been proven yet. In the South, there’s Southern tick-associated rash illness. Out west, there’s a new type of spotted fever. And across a big swath of the country, there’s a disease called ehrlichiosis.

Tick-borne Lyme disease exploding into Michigan; human cases up 5-fold

Tick-borne Lyme disease exploding into Michigan; human cases up 5-fold, The Free Press, Feb 23, 2017The Lyme disease spike in Michigan correlates with the spread of blacklegged ticks here. In 1998, the ticks were established in only five counties — Berrien County in the southwestern-most Lower Peninsula, and four counties in the Upper Peninsula — and reported in 22 other counties. By 2016, however, the ticks were established in almost five times as many counties — established in 24 Michigan counties and reported in 18 others. The ticks have overtaken the entirety of the Lake Michigan shoreline in the Lower Peninsula, from Charlevoix to St. Joseph. But tick populations are not staying confined to coastal counties, becoming established increasingly to the east in the southern part of the state.
[Saline resident, who had not traveled outside the county,] Feldkamp said she never got her primary care doctor, neurologist, or oncologist to take Lyme disease seriously. “And once I started being vocal about it on Facebook, I started hearing from all these other people suffering from Lyme disease who’ve had a similar experience with their doctors,” she said.
Lyme Disease in Michigan

Excessive deer populations hurt native plant biodiversity

Excessive deer populations hurt native plant biodiversity
PhysOrg, March 11, 2014

To study the effect of rampant deer on trillium and garlic mustard populations, Kalisz and colleagues established multiple 196-square-meter plots in the forest. Half were fenced to exclude deer. Years of observation and hours of statistical analysis later, Kalisz and her colleagues have found that in plots where deer were excluded, the trillium population is increasing and the garlic mustard population is trending toward zero.

Deer Browsing Delays Succession by Altering Aboveground Vegetation and Belowground Seed Banks

Deer Browsing Delays Succession by Altering Aboveground Vegetation and Belowground Seed Banks
PLOS ONE, March 2014

Soil seed bank composition is important to the recovery of natural and semi-natural areas from disturbance and serves as a safeguard against environmental catastrophe. White-tailed deer (Odocoileus virginianus) populations have increased dramatically in eastern North America over the past century and can have strong impacts on aboveground vegetation, but their impacts on seed bank dynamics are less known. To document the long-term effects of deer browsing on plant successional dynamics, we studied the impacts of deer on both aboveground vegetation and seed bank composition in plant communities following agricultural abandonment. In 2005, we established six 156 15 m fenced enclosures and paired open plots in recently fallowed agricultural fields near Ithaca, NY, USA. In late October of each of six years (2005–2010), we collected soil from each plot and conducted seed germination cycles in a greenhouse to document seed bank composition.

These data were compared to measurements of aboveground plant cover (2005–2008) and tree density (2005–2012). The impacts of deer browsing on aboveground vegetation were severe and immediate, resulting in significantly more bare soil, reduced plant biomass, reduced recruitment of woody species, and relatively fewer native species. These impacts persisted throughout the experiment. The impacts of browsing were even stronger on seed bank dynamics. Browsing resulted in significantly decreased overall species richness (but higher diversity), reduced seed bank abundance, relatively more short-lived species (annuals and biennials), and fewer native species. Both seed bank richness and the relative abundance of annuals/biennials were mirrored in the aboveground vegetation. Thus, deer browsing has long-term and potentially
reinforcing impacts on secondary succession, slowing succession by selectively consuming native perennials and woody species and favoring the persistence of short-lived, introduced species that continually recruit from an altered seed bank.