Monday, 9 June 2008

Spring ephemerals

Trillium, courtesy of ColdClimateGardening
Excerpts from Barbara Whitaker, "Forest's Colorful Jewels in a Fight for Their Lives," New York Times 17 May 2005, reprinted by U of Florida Extension FYN Florida Yards and Neighbourhoods.

Flowers are being "devastated," says Keith P. Tomlinson, manager of Meadowlark Botanical Gardens in suburban Washington. Since March his wildflowers have been putting on a carefully choreographed show. The bloodroots took the stage first, unfurling white petals around their yellow hearts... followed by delicate Virginia bluebells and dainty pink spring beauties. [In mid-May] red, white and yellow trilliums joined blue dwarfcrested iris and a handful of pink lady's slippers... [but] the spring ephemerals of deciduous forests are under siege from Maine through South Carolina and stretching to the Midwest.

On Mather Gorge trail [aka Mathildaville] in Great Falls National Park a few miles away on the Potomac River... bluebells, golden ragwort and trilliums are being crowded out by invasive plants and ravaged by deer [which have vastly increased due to human interference with natural systems]... True spring ephemerals like Dutchman's breeches, Virginia bluebells, trout lilies and spring beauties flower and die in the few weeks after winter's freeze has broken and before the trees have fully leafed out and blocked the sun. The ephemerals live the rest of the year underground and are believed to have life spans of tens to hundreds of years like the trees around them.

In Wisconsin, where historic data from several hundred forested sites are available, native species including the spring ephemerals and other related wildflowers have declined 18 percent over the last 50 years... At the Daniel Smiley Research Center of the Mohonk Preserve in New Paltz NY, researchers have been studying a stand of red trillium for several years to determine the deer's effects. "We can get the first flower out, but probably within a week almost all the plants are chewed off," says the director. "The plants were about half their previous size and did not flower". Rivaling deer for destructiveness are invasive plants like Japanese honeysuckle, garlic mustard and mile-a-minute weed.

Sally Anderson of the Virginia Native Plant Society says invasive plants like garlic mustard and stilt weed constantly competed for space on her acre and a half in the Shenandoah Valley. ... clearing nearby lots to build houses has taken habitat once rich with trillium grandiflorum. "The seeds of a lot of our spring ephemerals are transported by ants," she noted. "So if confined by roads and driveways and houses, the plants not going to move as easily, and they are going to lose the genetic intermixing that keeps them healthy."

Some botanists and ecologists say the loss of biodiversity in the groundcover is a much bigger story than the threat to wildflowers.... In parts of the Eastern United States, forests are widely thought to be on the rebound as land cleared for agriculture and now abandoned reverts to its former state. But much of the diversity in those forests is missing..."What we have back is a shadow" [of the original forest] says Dr. Canham of the Institute of Ecosystem Studies.

See also Sebasticook River Watershed Association, Ivy Creek Foundation, Wabash College blog, Kerrdelune's blog. Holly's Picasa album, Ellis Hollow album, NH Public Radio, Cannon River MN, Travel Wisconsin, Dr Martin Pfeiffer's research on ants.

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